CRISPR-Cas technologies have emerged as powerful and versatile tools in gene therapy. In addition to the widely used SpCas9 system, alternative platforms including modified amino acid sequences, size-optimized variants, and other Cas enzymes from diverse bacterial species have been developed to apply this technology in various genetic contexts. In addition, base editors and prime editors for precise gene editing, the Cas13 system targeting RNA, and CRISPRa/i systems have enabled diverse and adaptable approaches for genome and RNA editing, as well as for regulating gene expression. Typically, CRISPR-Cas components are transported to the target in the form of DNA, RNA, or ribonucleoprotein complexes using various delivery methods, such as electroporation, adeno-associated viruses, and lipid nanoparticles. To amplify therapeutic efficiency, continued developments in targeted delivery technologies are required, with increased safety and stability of therapeutic biomolecules. CRISPR-based therapeutics hold an inexhaustible potential for the treatment of many diseases, including rare congenital diseases, by making permanent corrections at the genomic DNA level. In this review, we present various CRISPR-based tools, their delivery systems, and clinical progress in the CRISPR-Cas technology, highlighting its innovative prospects for gene therapy.

Dengue, caused by four serotypes of dengue viruses (DENV-1 to DENV-4), is the most prevalent and widely mosquito-borne viral disease affecting humans. Dengue virus (DENV) infection has been reported in over 100 countries, and approximately half of the world's population is now at risk. The paucity of universally licensed DENV vaccines highlights the urgent need to address this public health concern. Action and attention to antibody-dependent enhancement increase the difficulty of vaccine development. With the worsening dengue fever epidemic, Dengvaxia^® (CYD-TDV) and Qdenga^® (TAK-003) have been approved for use in specific populations in affected areas. However, these vaccines do not provide a balanced immune response to all four DENV serotypes and the vaccination cannot cover all populations. There is still a need to develop a safe, broad-spectrum, and effective vaccine to address the increasing number of dengue cases worldwide. This review provides an overview of the existing DENV vaccines, as well as potential candidates for future studies on DENV vaccine development, and discusses the challenges and possible solutions in the field.

Protein solubility is a critical factor in the production of recombinant proteins, which are widely used in various industries, including pharmaceuticals, diagnostics, and biotechnology. Predicting protein solubility remains a challenging task due to the complexity of protein structures and the multitude of factors influencing solubility. Recent advances in computational methods, particularly those based on machine learning, have provided powerful tools for predicting protein solubility, thereby reducing the need for extensive experimental trials. This review provides an overview of current computational approaches to predict protein solubility. We discuss the datasets, features, and algorithms employed in these models. The review aims to bridge the gap between computational predictions and experimental validations, fostering the development of more accurate and reliable solubility prediction models that can significantly enhance recombinant protein production.

The increasing environmental concerns regarding conventional plastics have led to a growing demand for sustainable alternatives, such as biodegradable plastics. Yeast cell factories, specifically Saccharomyces cerevisiae and Yarrowia lipolytica, have emerged as promising platforms for bioplastic production due to their scalability, robustness, and ease of manipulation. This review highlights synthetic biology approaches aimed at developing yeast cell factories to produce key biodegradable plastics, including polylactic acid (PLA), polyhydroxyalkanoates (PHAs), and poly (butylene adipate-co-terephthalate) (PBAT). We explore recent advancements in engineered yeast strains that utilize various synthetic biology strategies, such as the incorporation of new genetic elements at the gene, pathway, and cellular system levels. The combined efforts of metabolic engineering, protein engineering, and adaptive evolution have enhanced strain efficiency and maximized product yields. Additionally, this review addresses the importance of integrating computational tools and machine learning into the Design-Build-Test-Learn cycle for strain development. This integration aims to facilitate strain development while minimizing effort and maximizing performance. However, challenges remain in improving strain robustness and scaling up industrial production processes. By combining advanced synthetic biology techniques with computational approaches, yeast cell factories hold significant potential for the sustainable and scalable production of bioplastics, thus contributing to a greener bioeconomy.

Streptomyces are a crucial source of bioactive secondary metabolites with significant clinical applications. Recent studies of bacterial and metagenome-assembled genomes have revealed that Streptomyces harbors a substantial number of uncharacterized silent secondary metabolite biosynthetic gene clusters (BGCs). These BGCs represent a vast diversity of biosynthetic pathways for natural product synthesis, indicating significant untapped potential for discovering new metabolites. To exploit this potential, genome mining using comprehensive strategies that leverage extensive genomic databases can be conducted. By linking BGCs to their encoded products and integrating genetic manipulation techniques, researchers can greatly enhance the identification of new secondary metabolites with therapeutic relevance. In this context, we present a step-by-step guide for using the antiSMASH pipeline to identify secondary metabolite-coding BGCs within the complete genome of a novel Streptomyces strain. This protocol also outlines gene manipulation methods that can be applied to Streptomyces to activate cryptic clusters of interest and validate the functions of biosynthetic genes. By following these guidelines, researchers can pave the way for discovering and characterizing valuable natural products.

The widespread use of antibiotics in aquaculture has led to the emergence of multidrug-resistant pathogens and environmental concerns, highlighting the need for sustainable, eco-friendly alternatives. In this study, we isolated and characterized three novel bacteriophages from aquaculture effluents in Korean shrimp farms that target the key Vibrio pathogens, Vibrio harveyi, and Vibrio parahaemolyticus. Bacteriophages were isolated through environmental enrichment and serial purification using double-layer agar assays. Transmission electron microscopy revealed that the phages infecting V. harveyi, designated as vB_VhaS-MS01 and vB_VhaS-MS03, exhibited typical Siphoviridae morphology with long contractile tails and icosahedral heads, whereas the phage isolated from V. parahaemolyticus (vB_VpaP-MS02) displayed Podoviridae characteristics with an icosahedral head and short tail.

Whole-genome sequencing produced complete, circularized genomes of 81,710 bp for vB_VhaS-MS01, 81,874 bp for vB_VhaS-MS03, and 76,865 bp for vB_VpaP-MS02, each showing a modular genome organization typical of Caudoviricetes. Genomic and phylogenetic analyses based on the terminase large subunit gene revealed that although vB_VhaS-MS01 and vB_VhaS-MS03 were closely related, vB_VpaP-MS02 exhibited a distinct genomic architecture that reflects its unique morphology and host specificity. Collectively, these comparative analyses demonstrated that all three phages possess genetic sequences markedly different from those of previously reported bacteriophages, thereby establishing their novelty. One-step growth and multiplicity of infection (MOI) experiments demonstrated significant differences in replication kinetics, such as burst size and lytic efficiency, among the phages, with vB_VhaS-MS03 maintaining the most effective bacterial control, even at an MOI of 0.01. Additionally, host range assays showed that vB_VhaS-MS03 possessed a broader spectrum of activity, supporting its potential use as a stand-alone agent or key component of phage cocktails. These findings highlight the potential of region-specific phage therapy as a targeted and sustainable alternative to antibiotics for controlling Vibrio infections in aquaculture.

The escalating antibiotic resistance crisis poses a significant challenge to global public health, threatening the efficacy of current treatments and driving the emergence of multidrug-resistant pathogens. Among the various factors associated with bacterial antibiotic resistance, small regulatory RNAs (sRNAs) have emerged as pivotal post-transcriptional regulators which orchestrate bacterial adaptation to antibiotic pressure via diverse mechanisms. This review consolidates the current knowledge on sRNA-mediated mechanisms, focusing on drug uptake, drug efflux systems, lipopolysaccharides, cell wall modification, biofilm formation, and mutagenesis. Recent advances in transcriptomics and functional analyses have revealed novel sRNAs and their regulatory networks, expanding our understanding of resistance mechanisms. These findings highlight the potential of targeting sRNA-mediated pathways as an innovative therapeutic strategy to combat antibiotic resistance, and offer promising avenues for managing challenging bacterial infections.

Precise and tunable gene expression is crucial for various biotechnological applications, including protein overexpression, fine-tuned metabolic pathway engineering, and dynamic gene regulation. Untranslated regions (UTRs) of mRNAs have emerged as key regulatory elements that modulate transcription and translation. In this review, we explore recent advances in UTR engineering strategies for bacterial gene expression optimization. We discuss approaches for enhancing protein expression through AU-rich elements, RG4 structures, and synthetic dual UTRs, as well as ProQC systems that improve translation fidelity. Additionally, we examine strategies for fine-tuning gene expression using UTR libraries and synthetic terminators that balance metabolic flux. Finally, we highlight riboswitches and toehold switches, which enable dynamic gene regulation in response to environmental or metabolic cues. The integration of these UTR-based regulatory tools provides a versatile and modular framework for optimizing bacterial gene expression, enhancing metabolic engineering, and advancing synthetic biology applications.

This review explores current advancements in microbiome functional analysis enabled by next-generation sequencing technologies, which have transformed our understanding of microbial communities from mere taxonomic composition to their functional potential. We examine approaches that move beyond species identification to characterize microbial activities, interactions, and their roles in host health and disease. Genome-scale metabolic models allow for in-depth simulations of metabolic networks, enabling researchers to predict microbial metabolism, growth, and interspecies interactions in diverse environments. Additionally, computational methods for predicting metabolite profiles offer indirect insights into microbial metabolic outputs, which is crucial for identifying biomarkers and potential therapeutic targets. Functional pathway analysis tools further reveal microbial contributions to metabolic pathways, highlighting alterations in response to environmental changes and disease states. Together, these methods offer a powerful framework for understanding the complex metabolic interactions within microbial communities and their impact on host physiology. While significant progress has been made, challenges remain in the accuracy of predictive models and the completeness of reference databases, which limit the applicability of these methods in under-characterized ecosystems. The integration of these computational tools with multi-omic data holds promise for personalized approaches in precision medicine, allowing for targeted interventions that modulate the microbiome to improve health outcomes. This review highlights recent advances in microbiome functional analysis, providing a roadmap for future research and translational applications in human health and environmental microbiology.

Extracellular vesicles derived from probiotics have received considerable attention for their pivotal role in bacterial‒host communication. These nanosized, bilayer-encapsulated vesicles carry diverse bioactive molecules, such as proteins, lipids, nucleic acids, and metabolites. Currently, ample evidence has emerged that probiotic extracellular vesicles may modulate several processes of host physiological hemostasis and offer therapeutic benefits. This review examines the biogenesis, composition, and immunomodulatory functions of probiotic-derived extracellular vesicles in probiotic–host interactions, highlighting the therapeutic potential of probiotic extracellular vesicles in the diagnosis and treatment of conditions such as cancer and inflammatory bowel disease. We further summarize the techniques for the separation and purification of extracellular vesicles, providing a methodological foundation for future research and applications. Although the field of probiotic extracellular vesicle research is still in its infancy, the prospects for their application in the biomedical field are broad, potentially emerging as a novel therapeutic approach.

The increase of sequence data in public nucleotide databases has made DNA sequence-based identification an indispensable tool for fungal identification. However, the large proportion of mislabeled sequence data in public databases leads to frequent misidentifications. Inaccurate identification is causing severe problems, especially for industrial and clinical fungi, and edible mushrooms. Existing species identification pipelines require separate validation of a dataset obtained from public databases containing mislabeled taxonomic identifications. To address this issue, we developed FunVIP, a fully automated phylogeny-based fungal validation and identification pipeline (https://github.com/Changwanseo/FunVIP). FunVIP employs phylogeny-based identification with validation, where the result is achievable only with a query, database, and a single command. FunVIP command comprises nine steps within a workflow: input management, sequence-set organization, alignment, trimming, concatenation, model selection, tree inference, tree interpretation, and report generation. Users may acquire identification results, phylogenetic tree evidence, and reports of conflicts and issues detected in multiple checkpoints during the analysis. The conflicting sample validation performance of FunVIP was demonstrated by re-iterating the manual revision of a fungal genus with a database with mislabeled sequences, Fuscoporia. We also compared the identification performance of FunVIP with BLAST and q2-feature-classifier with two mass double-revised fungal datasets, Sanghuangporus and Aspergillus section Terrei. Therefore, with its automatic validation ability and high identification performance, FunVIP proves to be a highly promising tool for achieving easy and accurate fungal identification.

Dual specificity phosphatases (DUSPs), a subfamily of the protein tyrosine phosphatase (PTP) family, dephosphorylate not only phosphotyrosine but also phosphoserine and phosphothreonine residues. Beyond the 26 members of this family in humans, DUSPs represent the only type of PTPs found across a wide range of microorganisms, including bacteria, archaea, and viruses. This review presents a comprehensive structural analysis of human and microbial DUSPs. These proteins commonly share core features, such as a typical DUSP fold, shallow active site pocket, signature active site motif known as the P-loop, and conserved aspartate residue that acts as a general acid/base. However, DUSPs from diverse microorganisms also display unique structural and functional characteristics. Pseudomonas aeruginosa TpbA is the only bacterial DUSP identified to date, while a second candidate was proposed in this review. Archaeal DUSPs are hyperthermostable, contain a unique motif in their P-loops, and employ dual general acid/base residues. Poxviral DUSPs are characterized by the formation of domain-swapped homodimers. The presence of DUSPs across all domains of life and viruses, along with their low specificity for phosphorylated amino acids and structural similarity to classical PTPs, suggests that DUSPs represent the ancestral form of PTPs.

Antarctic fungi can effectively adapt to extreme environments, which leads to the production of unique bioactive compounds. Studies on the discovery of fungi in the diverse environments of Antarctica and their potential applications are increasing, yet remain limited. In this study, fungi were isolated from various substrates on the Fildes Peninsula in Antarctica and screened for their antibiosis activity against two significant plant pathogenic fungi, Botrytis cinerea and Fusarium culmorum. Phylogenetic analysis using multiple genetic markers revealed that the isolated Antarctic fungal strains are diverse, some of which are novel, emphasizing the underexplored biodiversity of Antarctic fungi. These findings suggest that these fungi have potential for the development of new antifungal agents that can be applied in agriculture to manage fungal plant pathogens. Furthermore, the antibiosis activities of the isolated Antarctic fungi were evaluated using a dual-culture assay. The results indicated that several strains from the genera Cyathicula, Penicillium, and Pseudeurotium significantly inhibited pathogen growth, with Penicillium pancosmium showing the highest inhibitory activity against Botrytis cinerea. Similarly, Aspergillus and Tolypocladium strains exhibited strong antagonistic effects against Fusarium culmorum. This study enhances our understanding of Antarctic fungal diversity and highlights its potential for biotechnological applications.

Bacteria-free reverse genetics techniques are crucial for the efficient generation of recombinant viruses, bypassing the need for labor-intensive bacterial cloning. These methods are particularly relevant for studying the pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19. This study compared the efficiency of three bacteria-free approaches—circular polymerase extension reaction (CPER) with and without nick sealing and infectious sub-genomic amplicons (ISA)—to bacterial artificial chromosome (BAC)-based technology for rescuing SARS-CoV-2. Significant differences in viral titers following transfection were observed between methods. CPER with nick sealing generated virus titers comparable to those of the BAC-based method and 10 times higher than those of the standard CPER. In contrast, ISA demonstrated extremely low efficiency, as cytopathic effects were detected only after two passages. All rescued viruses exhibited replication kinetics consistent with those of the original strain, with no significant deviation in replication capacity. Furthermore, the utility of CPER and ISA in genetically modifying SARS-CoV-2 was demonstrated by successfully inserting the gene encoding green fluorescent protein into the genome. Overall, this study underscores the potential of bacteria-free methods, such as CPER and ISA, in advancing SARS-CoV-2 research while highlighting their significant differences in efficiency.

Pectin-rich biomass, derived from fruit and citrus processing waste, presents a promising yet underutilized resource for sustainable biofuel and biochemical production. Its low lignin content and high concentrations of fermentable sugars, including D-galacturonic acid, L-arabinose, and D-xylose, make it an attractive feedstock. Unlike lignocellulosic biomass, pectin-rich hydrolysates require milder pretreatment, improving sugar recovery efficiency. However, industrial strains such as Saccharomyces cerevisiae exhibit strong glucose preference, limiting the efficient co-fermentation of mixed sugars. While prior reviews have broadly addressed lignocellulosic biomass utilization, this mini-review uniquely centers on the specific metabolic challenges and opportunities associated with pectin-rich feedstocks. In addition to incorporating established strategies for the co-utilization of cellobiose and xylose, we highlight recent advances that allow S. cerevisiae to metabolize carbon sources specifically from pectin-rich biomass, such as L-arabinose and D-galacturonic acid—monomers not prevalent in traditional lignocellulosic biomass. By integrating discussions on sugar transport engineering, redox balancing, and pathway optimization, this review offers a comprehensive framework to overcome glucose repression and support efficient co-fermentation of carbon sources from conventional and pectin-rich biomass. Drawing on these advances, we outline practical strategies to enhance fermentation performance and expand the valorization of food processing residues in biomanufacturing.

The innate immune system relies on innate immune sensors, such as pattern recognition receptors (PRRs), to detect pathogens and initiate immune responses, crucial for controlling infections but also implicated in inflammatory diseases. These innate immune sensors, including Toll-like receptors (TLRs), nod-like receptors (NLRs), RIG-I-like receptors (RLRs), absent in melanoma 2 (AIM2), and Z-DNA binding protein 1 (ZBP1) trigger signaling pathways that produce cytokines, modulating inflammation and cell death. Traditional therapies focus on directly targeting pathogens; however, host-targeting therapeutic strategies have emerged as innovative approaches to modulate innate immune sensor activity. These strategies aim to fine-tune the immune response, either enhancing antiviral defenses or mitigating hyperinflammation to prevent tissue damage. This review explores innate immune sensor-based therapeutic approaches, including inhibitors, agonists, and antagonists, that enhance antiviral defense or suppress harmful inflammation, highlighting innate immune sensors as promising targets in infectious and inflammatory disease treatment.

Antimicrobial resistance (AMR) poses a serious threat to public health, with the emergence of extended-spectrum beta-lactamases (ESBLs) in Enterobacteriaceae, particularly Escherichia coli, raising significant concerns. This study aims to elucidate the drivers of antimicrobial resistance, and the global spread of cefotaxime-resistant E. coli (CREC) strains. Whole-genome sequencing (WGS) was performed to explore genome-level characteristics, and phylogenetic analysis was conducted to compare twenty CREC strains from this study, which were isolated from broiler chicken farms in Bangladesh, with a global collection (n = 456) of CREC strains from multiple countries and hosts. The MIC analysis showed over 70% of strains isolated from broiler chickens exhibiting MIC values ≥ 256 mg/L for cefotaxime. Notably, 85% of the studied farms (17/20) tested positive for CREC by the end of the production cycle, with CREC counts increasing from 0.83 ± 1.75 log10 CFU/g feces on day 1 to 5.24 ± 0.72 log10 CFU/g feces by day 28. WGS revealed the presence of multiple resistance genes, including bla_CTX-M, which was found in 30% of the strains. Phylogenetic comparison showed that the Bangladeshi strains were closely related to strains from diverse geographical regions and host species. This study provides a comprehensive understanding of the molecular epidemiology of CREC. The close phylogenetic relationships between Bangladeshi and global strains demonstrate the widespread presence of cefotaxime-resistant bacteria and emphasize the importance of monitoring AMR in food-producing animals to mitigate the spread of resistant strains.

A Gram-stain-negative, aerobic, non-motile, rod-shaped, and orange-pigmented bacterium, designated CJ426^T, was isolated from ginseng soil in Anseong, Korea. Strain CJ426^T grew optimally on Reasoner’s 2A agar at 30°C and pH 7.0 in the absence of NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain CJ426^T belonged to the family Chitinophagaceae and had the highest sequence similarity with Niabella hibiscisoli KACC 18857^T (98.7%). The 16S rRNA gene sequence similarities with other members of the genus Niabella ranged from 92.3% to 98.1%. Phylogenomic analyses and overall genomic relatedness indices, including average nucleotide identity, average amino acid identity, and the percentage of conserved proteins values, supported the classification of strain CJ426^T as a representative of a novel genus within the family Chitinophagaceae. Furthermore, genome-based analyses suggested that five members of the genus Niabella, including N. aquatica, N. defluvii, N. ginsengisoli, N. hibiscisoli, and, N. yanshanensis, should be separated from other Niabella species and be assigned as a novel genus. The major isoprenoid quinone of strain CJ426^T was menaquinone-7 (MK-7). The predominant polar lipids were phosphatidylethanolamine and six unidentified aminolipids. The major fatty acids were iso-C_15:0, iso-C_15:1 G, and iso-C_17:0 3-OH. The genome of strain CJ426^T was 6.3 Mbp in size, consisting of three contigs, with a G + C content of 41.9%. Based on a polyphasic taxonomic approach, strain CJ426^T represents a novel genus and species within the family Chitinophagaceae, for which the name Paraniabella aurantiaca gen. nov., sp. nov. is proposed. The type strain is CJ426^T (= KACC 23908^T = JCM 37728^T).

Atopic dermatitis (AD) is a widespread inflammatory skin condition that affects the population worldwide. Given the implication of microbiota in AD pathogenesis, we investigated whether human-derived Lactobacillus strains could modulate AD. In this study, we identified Lactobacillus crispatus KBL693 as a probiotic candidate for AD treatment. In vitro, KBL693 suppressed mast cell degranulation and IL-4 production by T cells, suggesting its ability to attenuate key type 2 immune responses. Consistent outcomes were observed in a murine AD model, where oral administration of KBL693 alleviated disease symptoms and reduced hallmark type 2 immune markers, including plasma IgE as well as IL-4, IL-5, and IL-13 levels in skin lesions. In addition to downregulating these AD-associated immune responses, KBL693 promoted regulatory T cell (Treg) expansion in mesenteric lymph nodes, indicating its potential to restore immune balance. Collectively, these findings highlight the therapeutic potential of KBL693 for AD through enhancement of Tregs and suppression of type 2 immune responses.

Two Gram-stain-negative, strictly aerobic, non-motile, rod-shaped bacteria, designated D3-12ᵀ and G2-2ᵀ, were isolated from the phycosphere of marine red algae. Both strains exhibited catalase- and oxidase-positive activities. Strain D3-12ᵀ grew optimally at 30°C, pH 7.0, and 2.0–3.0% (w/v) NaCl, while strain G2-2ᵀ showed optimal growth at 30°C, pH 7.0, and 2.0% NaCl. Ubiquinone-10 was the sole respiratory quinone in both strains. The major fatty acids (> 5%) in strain D3-12ᵀ were feature 8 (C_18:1 ω7c and/or C_18:1 ω6c), 11-methyl-C_18:1 ω7c, and C_16:0, while strain G2-2ᵀ contained summed feature 8 and C_16:0. The predominant polar lipids in strain D3-12ᵀ were phosphatidylcholine, phosphatidylglycerol, and phosphatidylethanolamine, whereas strain G2-2ᵀ contained phosphatidylglycerol and diphosphatidylglycerol. The genomic DNA G + C content was 59.9% for strain D3-12ᵀ and 60.2% for strain G2-2ᵀ. Phylogenetic analyses based on 16S rRNA and whole-genome sequences placed both strains into distinct lineages within the family Roseobacteraceae, separate from previously described genera. Genome-based relatedness metrics, including average nucleotide identity, digital DNA-DNA hybridization, average amino acid identity, and percentage of conserved proteins, further confirmed that these strains represent novel genera. Based on phenotypic, chemotaxonomic, and molecular characteristics, strains D3-12ᵀ and G2-2ᵀ are proposed as novel genera: Phycobium rhodophyticola gen. nov., sp. nov. (D3-12ᵀ = KACC 22712ᵀ = JCM 35528ᵀ) and Aliiphycobium algicola gen. nov., sp. nov. (G2-2ᵀ = KACC 22602ᵀ = JCM 35752ᵀ). Additionally, metabolic features relevant to interactions with marine algae, including genes associated with carbohydrate-active enzymes, vitamin biosynthesis, phenylacetic acid production, and bacterioferritin synthesis, were bioinformatically investigated.

Systemic sclerosis (SSc) is a chronic autoimmune disorder characterised by skin fibrosis and internal organ involvement. Disruptions in the microbial communities on the skin may contribute to the onset of autoimmune diseases that affect the skin. However, current research on the skin microbiome in SSc is lacking. This study aimed to investigate skin microbiome associated with disease severity in SSc. Skin swabs were collected from the upper limbs of 46 healthy controls (HCs) and 36 patients with SSc. Metagenomic analysis based on the 16S rRNA gene was conducted and stratified by cutaneous subtype and modified Rodnan skin score (mRSS) severity. Significant differences in skin bacterial communities were observed between the HCs and patients with SSc, with further significant variations based on subtype and mRSS severity. The identified biomarkers were Bacteroides and Faecalibacterium for patients with diffuse cutaneous SSc with high mRSS (≥ 10) and Mycobacterium and Parabacteroides for those with low mRSS (< 10). Gardnerella, Abies, Lactobacillus, and Roseburia were the biomarkers in patients with limited cutaneous SSc (lcSS) and high mRSS, whereas Coprococcus predominated in patients with lcSS and low mRSS. Cutaneous subtype analysis identified Pediococcus as a biomarker in the HCs, whereas mRSS analysis revealed the presence of Pseudomonas in conjunction with Pediococcus. In conclusion, patients with SSc exhibit distinct skin microbiota compared with healthy controls. Bacterial composition varies by systemic sclerosis cutaneous subtype and skin thickness.

The global spread of COVID-19 has underscored the urgent need for advanced tools to study emerging coronaviruses. Reverse genetics systems have become indispensable for dissecting viral gene functions, developing live-attenuated vaccine candidates, and identifying antiviral targets. In this study, we describe a robust and efficient reverse genetics platform for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The system is based on the assembly of a full-length infectious cDNA clone from seven overlapping fragments, each flanked by homologous sequences to facilitate seamless assembly using the Gibson assembly method. Individual cloning of each fragment into plasmids enables modular manipulation of the viral genome, allowing rapid site-directed mutagenesis by fragment exchange. Infectious recombinant virus was successfully recovered from the assembled cDNA, exhibiting uniform plaque morphology and genetic homogeneity compared to clinical isolates. Additionally, fluorescent reporter viruses were generated to enable real-time visualization of infection, and the effects of different mammalian promoters on viral rescue were evaluated. This reverse genetics platform enables efficient generation and manipulation of recombinant SARS-CoV-2, providing a valuable resource for virological research and the development of preventive and therapeutic antiviral measures.

Marine organisms often form symbiotic relationships with various microorganisms to adapt and thrive in harsh environments. These symbiotic microbes contribute to host survival by providing nutrition, modulating the hosts’ immune system, and supporting overall physiological stability. Advances in high-throughput sequencing technologies have enabled a deeper understanding of the structure and function of symbiotic microbial communities, as well as host-microbe interactions. Notably, symbiotic bacteria associated with marine invertebrates such as corals and sponges are recognized as a potential source of useful bioactive compounds, including antibiotics and enzymes. However, obtaining high-quality microbial DNA from host tissues still remains a technical challenge due to the presence of unknown substances. This study focuses on optimizing sample preparation and DNA extraction procedures and additional purification to improve the recovery of microbial DNA while minimizing host DNA contamination. Comparison between several methods was conducted using sponge samples to evaluate DNA quality and microbial recovery. A sample designated as 2110BU-001 was collected from the east coast of the Republic of Korea and used for culture-independent microbial cell isolation. Total bacterial DNA was extracted by using a manual Phenol-Chloroform protocol and three commercial kits. DNA extracted using the standard manual method showed both the highest yield and the largest fragment size. However, PCR (Polymerase chain reaction) test showed that quality of manually extracted DNA was not enough for sequencing. Therefore, the quality of DNA was improved through additional purification steps. Briefly, host eukaryotic cells were removed by mechanical process and almost only bacterial DNA was successfully obtained by combination of manual extraction method and further purification processes. The established protocol was successfully introduced to extraction of metagenomic DNA from mussel and jellyfish microbiomes, indicating that it can be widely applied to various marine organisms.

Gout is an inflammatory arthritis resulting from the deposition of monosodium urate crystals. Urate-lowering therapies for gout have limitations, including side effects and limited efficacy, highlighting the need for novel therapeutic approaches to improve patient outcomes. In this context, our research team conducted a microbiome analysis of fecal samples from healthy individuals and gout patients, identifying Bifidobacterium as a key biomarker. Subsequently, we isolated and identified this strain, B. longum PMC72, and demonstrated its efficacy in a gout mouse model. In potassium oxonate (PO)-induced hyperuricemia mice, PMC72 significantly alleviated nausea, gait disturbances, ankle inflammation, and improved renal health. These effects were associated with marked reductions in oxidative stress markers, including serum uric acid, blood urea nitrogen, hepatic xanthine oxidase, and malondialdehyde (MDA) levels in serum, liver, and joint samples, as well as the downregulation of inflammation and uric acid transport-related gene expression in kidney samples. These benefits were comparable to those treated with Febuxostat, a standard urate-lowering therapy for gout. Furthermore, gut microbiome analysis revealed that PMC72 restored dysbiosis induced by hyperuricemia, contrasting with the reduced microbial diversity observed with febuxostat alone, and showed a complete recovery to eubiosis when combined with Febuxostat. These findings position PMC72 as a promising microbial therapeutic candidate for gout management, demonstrating significant development potential and serving as a benchmark for reverse translational microbiome-based therapeutic research.

The 2015 Zika virus (ZIKV) outbreak in Brazil and its global spread underscored the urgent need for effective and broadly protective vaccines. While C57BL/6 and BALB/c mice are widely used in preclinical vaccine research, direct comparisons of their ability to elicit ZIKV-specific neutralizing antibodies (nAbs) remain limited. This study aimed to systematically evaluate and compare the immunogenic potential of these two common mouse strains across diverse vaccine platforms, focusing on their capacity to generate functional neutralizing antibody responses. We assessed nAb and IgG responses following four vaccination strategies: (1) DNA vaccine encoding prMEΔTM followed by E protein domain III boost, (2) recombinant EΔTM protein expressed using baculovirus system, (3) formalin-inactivated ZIKV, and (4) live ZIKV. Although both strains generated detectable ZIKV- and E protein-specific IgG, the magnitude and quality of responses varied by vaccine platform and strain. Notably, C57BL/6 mice consistently mounted significantly higher nAb titers than BALB/c mice across all immunization groups, including subunit- and whole-virus-based vaccines. In contrast, BALB/c mice showed lower or undetectable nAb responses, despite comparable or higher total IgG levels in some cases. These findings show that host genetic background is a critical determinant of vaccine-induced neutralization and underscore the importance of selecting appropriate animal models in ZIKV vaccine development. C57BL/6 mice, due to their robust nAb responses, represent a reliable model for evaluating vaccine immunogenicity. Conversely, the limited nAb responses in BALB/c mice position them as a potential low-responder model, offering a stringent system to test the potency and breadth of protective immunity under suboptimal conditions.

The Bacillus subtilis spore crust is an exceptionally robust proteinaceous layer that protects spores under extreme environmental conditions. Among its key components, CgeA, a glycosylation-associated protein, plays a critical role in modifying crust properties through its glycosylated moiety, enhancing spore dispersal in aqueous environments. In this study, we present the high-resolution cryo-electron microscopy structure of the core region of CgeA at 3.05 Å resolution, revealing a doughnut-like hexameric assembly. The N-terminal regions are disordered, whereas the C-terminal region forms the core of the hexamer. Although the loop containing Thr112 was not resolved in the density map, its location can be inferred from surrounding residues, suggesting that Thr112 is situated on the exposed surface of the hexamer. On the opposite face, a distinct electrostatic pattern is observed, featuring a negatively charged central pore and a positively charged outer surface. Modeling and biochemical studies with the putative glycosyltransferase CgeB provide insights into how the glycosyl group is transferred to Thr112. This study offers a molecular-level understanding of the assembly, glycosylation, and environmental adaptability of the B. subtilis spore crust, with valuable implications for controlling spore formation in industrial applications.

This study aimed to determine if the microbiota in four different oral sites and the oral health status differ between patients with primary Sjögren’s syndrome (pSS), non-pSS sicca symptoms, and healthy controls. All participants underwent an interview and clinical oral examination. Stimulated whole saliva (SWS), supragingival plaque (SGP), buccal mucosa tissue (BLM), and tongue scrape (TGS) samples from 23 pSS patients, 36 patients with sicca symptoms, not fulfilling the classification criteria for pSS (non-pSS sicca), and 21 age-matched healthy controls (HC) were analyzed using V3–V4 16S rRNA gene amplicon sequencing, and determination of amplicon sequence variants (ASVs). PSS and non-pSS sicca patients did not differ with respect to oral health status, saliva flow rates, abundance of predominant genera, relative abundance on genus level or bacterial diversity in any of the oral sites. Both patient groups differed significantly from the healthy control group in the abundance of 61 ASVs across all sites. The alpha-diversity was lower in SGP from non-pSS sicca patients (p = 0.019), and in TGS from pSS patients (p = 0.04). The proportion of variation in the beta-diversity across all four sites could be explained by the diagnosis (pSS, non-pSS sicca, and HC). However, subgrouping of patients according to their stimulated salivary flow rates (SWS > 0.7 ml/min versus SWS ≤ 0.7 ml/min), revealed significantly different abundance of three ASVs in SWS, 11 in SGP, and six in TGS. Our findings suggest that hyposalivation rather than pSS itself modifies the microbial composition in oral site-specific patterns leading to oral diseases.

Synbiotics have become a new-age treatment tool for limiting the progression of metabolic dysfunction-associated steatotic liver disease; however, inclusive comparisons of various synbiotic treatments are still lacking. Here, we have explored and evaluated multiple synbiotic combinations incorporating three distinctive prebiotics, lactitol, lactulose and fructooligosaccharides. Of the synbiotic treatments evaluated, a combination of fructooligosaccharides and probiotics (FOS+Pro) exhibited superior protection against western diet-induced liver degeneration. This synbiotic (FOS+Pro) combination resulted in the lowest body weight gains, liver weights and liver/body weight ratios. The FOS+Pro synbiotic combination substantially alleviated liver histopathological markers and reduced serum AST and cholesterol levels. FOS+Pro ameliorated hepatic inflammation by lowering expression of proinflammatory markers including TNF-α, IL-1β, IL-6, and CCL2. FOS+Pro significantly improved steatosis by restricting the expression of lipid metabolic regulators (ACC1, FAS) and lipid transporters (CD36) in the liver. These findings are critical in suggesting that synbiotic treatments are capable of restraining western diet-induced metabolic dysfunction in the liver. Additionally, this study demonstrated that adding probiotic strains amplified the effectiveness of fructooligosaccharides but not all prebiotics.

Minicells, which are anucleate cells generated by irregular cell division, are emerging as promising drug delivery systems owing to advances in synthetic biology. However, their development is largely limited to a few model bacteria, highlighting the need to explore minicell platforms in alternative hosts. Lactiplantibacillus plantarum (L. plantarum), a probiotic bacterium classified as Generally Recognized as Safe, is an ideal candidate for such exploration. Minicell-producing L. plantarum was engineered by deleting the putative minD gene via plasmid-mediated homologous recombination, which inactivates cell division to form spherical minicells. Anucleate cells were isolated through differential centrifugation and filtration, followed by additional drug treatment to completely eliminate progenitor cells. Microscopy and flow cytometry analyses of the purified sample confirmed the absence of progenitor cells by DAPI staining. This protocol effectively produces bacterial minicells from L. plantarum for use in various biotechnological applications, including therapeutic agent delivery.

Microbial biosynthesis using yeast species offers numerous advantages to produce industrially relevant biofuels and biochemicals. Conventional metabolic engineering approaches in yeast focus on biosynthetic pathways in the cytoplasm, but these approaches are disturbed by various undesired factors including metabolic crosstalk, competing pathways and insufficient precursors. Given that eukaryotic cells contain subcellular organelles with distinct physicochemical properties, an emerging strategy to overcome cytosolic pathway engineering bottlenecks is through repurposing these organelles as specialized microbial cell factories for enhanced production of valuable chemicals. Here, we review recent progress and significant outcomes of harnessing organelle engineering for biofuels and biochemicals production in both conventional and non-conventional yeasts. We highlight key engineering strategies for the compartmentalization of biosynthetic pathways within specific organelles such as mitochondria, peroxisomes, and endoplasmic reticulum; involved in engineering of signal peptide, cofactor and energy enhancement, organelle biogenesis and dual subcellular engineering. Finally, we discuss the potential and challenges of organelle engineering for future studies and propose an automated pipeline to fully exploit this approach.

Two Gram-stain-positive, facultatively anaerobic, rod-shaped, and non-motile lactic acid bacterial strains, designated as strains CBA3605^T and CBA3606^T, were isolated from kimchi, a traditional Korean fermented food. Both strains were oxidase- and catalase-negative, non-spore-forming, non-hemolytic, and non-gas-producing. Optimal growth conditions for the two strains were observed at 30°C, pH 5.0, and 0% NaCl. The two genomes were composed of a circular chromosome and three plasmids and the DNA G + C content of 43.0%, respectively. Strains CBA3605^T and CBA3606^T were most closely related to Lactiplantibacillus (Lp.) pingfangensis 382-1^T with 16S rRNA sequence similarity of 99.4% and 99.1%, respectively. However, the orthologous average nucleotide identities between CBA3605^T and CBA3606^T were 91.7%, and those with strain 382-1^T were 76.9% and 76.5%, respectively. Digital DNA–DNA hybridization values between CBA3605^T and CBA3606^T were 45.0%, and those with strain 382-1^T were 21.4% and 21.0%, respectively. The major fatty acids detected in both strains included C_16:0, C_18:1 ω9c, and summed features 7 (C_19:1 ω7c, C_19:1 ω6c, C_19:0 cyclo ω10c, and/or C_19:0 ω6c). The peptidoglycan of both strains CBA3605^T and CBA3606^T contained meso-diaminopimelic acid and was classified as A4α type (L-Lys–D-Asp). In polar lipid analyses, only strain CBA3605^T contained aminophosphoglycolipid, which was absent in CBA3606^T, although both strains harbored same major polar lipids (diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine). Based on phenotypic, phylogenetic, genomic, biochemical, and chemotaxonomic analyses, strains CBA3605^T and CBA3606^T represent two novel species of the genus Lactiplantibacillus, for which the names Lactiplantibacillus koreensis sp. nov. and Lactiplantibacillus kimchii sp. nov. are proposed, with CBA3605^T (= KACC 81073BP^T = JCM 37965^T), and CBA3606^T (= KACC 81074BP^T = JCM 37966^T) as the type strains.

Nosocomial infections caused by Pseudomonas aeruginosa (P. aeruginosa) have become increasingly common, particularly among immunocompromised individuals, who experience high mortality rates and prolonged treatment durations due to the limited availability of effective therapies. In this study, we screened for anti-ExoS compounds targeting P. aeruginosa and identified pycnogenol (PYC) as a potent inhibitor of the type III secretion system (T3SS), a major virulence mechanism responsible for the translocation of effectors such as ExoS. Using ELISA, western blotting, and real-time PCR analyses in both P. aeruginosa and infected H292 cells, we found that PYC significantly reduced T3SS activity. Mechanistically, PYC suppressed the transcription of T3SS-related genes by downregulating exsA expression in P. aeruginosa. Furthermore, pretreatment with PYC attenuated the cytotoxic effects and reduced the expression of proinflammatory cytokines, including interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-18 (IL-18), in P. aeruginosa-infected H292 cells. These effects were associated with the inhibition of NF-κB signaling and inflammasome activation. Taken together, our findings suggest that PYC may serve as a promising therapeutic candidate against P. aeruginosa infections by targeting T3SS-mediated virulence and modulating host inflammatory responses.

Yeast prion [PSI+], an amyloid form of the translation termination factor Sup35p/eRF3, causes translational stop codon readthrough by sequestering functional Sup35p. This unique phenotype may be analyzed via [PSI+]−suppressible nonsense alleles, and has greatly contributed to the advancement in yeast prion research. For comparing canonical reporters, like chromosomal ade1−14 or ade2−1, and plasmid-borne ura3−14, the de novo generation and characteristics of [PSI+] was investigated across common yeast laboratory strains (BY4741, 74D−694, and 779−6A). The results showed significant variability in [PSI+] induction frequency among strains. [PSI+] was successfully induced in BY4741 and frequently in 74D−694 (via Ade⁺ selection), but not in 779−6A. Notably, [PSI+] clones, even from identical genetic backgrounds, displayed vastly different nonsense suppression phenotypes depending on the reporter allele used; resulting in diverse growth patterns and suppression levels. Quantitative analyses revealed that prion seed counts fluctuated significantly based on the detection allele and observed phenotype. Furthermore, Sup35p aggregate visualization revealed distinct structural patterns between BY4741 and 74D−694, indicating strain-specific differences. Transferring [PIN+] prion variants from different strains into a common [psi−][pin−] background yielded similar [PSI+] inducibility and seed numbers, suggesting that the observed phenotypic and quantitative diversities of [PSI+] prions stem primarily from the interplay between the specific reporter detection system and the host strain's genetic background rather than solely from inherent differences in the initial [PIN+] prion or fundamental changes in the [PSI+] protein itself. This study underscores the crucial need to consider both the detection methodology and host genetic context for accurate prion variant characterization.

Tella is a traditional beverage widely accepted by consumers, despite the lack of product consistency owing to its reliance on natural fermentation. This study aimed to identify potential industrial lactic acid bacteria (LAB) starter cultures based on their technological properties. Seven LAB strains isolated from Tella were characterized for their carbohydrate utilization, salt content, temperature, and acid tolerances, growth and acidification rates, and metabolite profiles. Most strains efficiently utilized various carbohydrates, with Lactiplantibacillus plantarum TDM41 showing exceptional versatility. The strains exhibited similar growth characteristics. Principal component analysis of stress tolerance properties revealed that L. plantarum TDM41, Pediococcus pentosaceus TAA01, and Leuconostoc mesenteroides TDB22 exhibited superior tolerance ability. Strong acidification properties were detected in the L. plantarum TDM41, P. pentosaceus TAA01, and Leuconostoc mesenteroides TDB22 strains after 24 h incubation at 30°C. L. plantarum TDM41 displayed the fastest acidification rate throughout the analysis period. All LAB strains produced significant amounts of diverse organic acids, including lactic acid, citric acid, acetic acid, malic acid, and succinic acid, with lactic acid being the primary acid produced by each strain. Overall, strains L. plantarum TDM41 and P. pentosaceus TAA01 prove to be potential candidates for Tella industrial starter cultures and similar cereal products owing to their robust technological properties.

Porins in the outer membrane (OM) of Gram-negative bacteria play two main functions: passage of various extracellular molecules and maintenance of membrane integrity. OmpC, a non-specific porin, is involved in both functions; however, the exact mechanism of maintenance of membrane integrity remains unknown. In this study, we found that inhibiting cardiolipin biosynthesis partially restored the growth defect of the ompC mutant under envelope stress. Among the three enzymes involved in cardiolipin biosynthesis, ClsABC, this effect is primarily associated with ClsA. Notably, the deletion of ClsA also suppressed the similar phenotypes of an Escherichia coli mutant lacking YhdP, a transmembrane protein involved in phospholipid transport from the inner membrane to the OM. Collectively, these results imply that OmpC may contribute to membrane integrity, partially through mechanisms linked to transport or biosynthesis of phospholipids such as cardiolipin.

Streptococcus mutans is a Gram-positive pathogen that causes dental caries and subsequent pulpal infection leading to pulpitis. Although dendritic cells (DCs) are known to be involved in disease progression and immune responses during S. mutans infection, little is known about which component of S. mutans is responsible for the DC responses. Although the mannose phosphotransferase system (Man-PTS) is the primary sugar transporter of S. mutans, it is also a potential virulence factor. Since Man-PTS subunit IID (ManIID) embedded on the bacterial membrane is indispensable for Man-PTS function, we investigated its role in the maturation and activation of DCs stimulated with a ManIID-deficient strain (Δpts) of S. mutans and recombinant ManIID (rManIID) protein. When mouse bone marrow-derived DCs were treated with heat-killed S. mutans wild-type (WT) or Δpts, bacterial adherence and internalization of Δpts were lower than those of WT. Moreover, the heat-killed S. mutans Δpts strain was inferior to the wild-type in inducing expression of phenotypic maturation markers, such as CD80, CD86, MHC-I, and MHC-II, and proinflammatory cytokine, IL-6. In line with the trends in marker expression, the endocytic capacity of DCs treated with the Δpts strain was comparable to that of untreated DCs whereas DCs treated with the WT strain dose-dependently lost their endocytic capacity. Furthermore, rManIID dose-dependently promoted both phenotypic maturation marker expression and IL-6 production by DCs. Collectively, these results demonstrate that ManIID plays a crucial role in the adhesion and internalization of S. mutans into DCs and is one of the major immune-stimulating agents responsible for maturation and activation of DCs during S. mutans infection.

Bladder cancer is the most common malignancy of the urinary tract and is a major health burden globally. Recent advances in microbiome research have revealed that the urinary tract harbors a resident microbial community, overturning the long-held belief in its sterility. Increasing evidence suggests that microbial dysbiosis and microbially derived metabolites contribute to bladder cancer carcinogenesis, progression, and therapeutic responses. Distinct microbial signatures have been observed in bladder cancer patients, with notable differences across disease stages and between primary and recurrent cases. Mechanistic studies have demonstrated that microbe-associated metabolites and toxins can drive DNA damage, chronic inflammation, extracellular matrix remodeling, and epithelial–mesenchymal transition. In addition, biofilm formation allows bacteria to evade immune responses and promotes persistent inflammation, creating a tumor-permissive niche. Beyond pathogenesis, microbial activity also influences therapeutic outcomes; for instance, some microbial pathways can inactivate frontline chemotherapy, while others generate metabolites with anti-tumor properties. Collectively, these patterns define a microbiota–metabolite–immunity axis, presenting opportunities for precision oncology. Targeting microbial pathways, profiling urinary microbiota, and harnessing beneficial metabolites offer promising advancements in biomarker discovery, prognostic refinement, and the development of novel therapeutic strategies for bladder cancer.

CRISPR-Cas9-based gene editing enables precise genetic modifications. However, its application to human cytomegalovirus (HCMV) remains challenging due to the large size of the viral genome and the essential roles of key regulatory genes. Here, we establish an optimized CRISPR-Cas9 system for precise labeling and functional analysis of HCMV immediate early (IE) genes. By integrating a multifunctional cassette encoding an auxin-inducible degron (AID), a self-cleaving peptide (P2A), and GFP into the viral genome via homology-directed repair (HDR), we achieved efficient knock-ins without reliance on bacterial artificial chromosome (BAC) cloning, a labor-intensive and time-consuming approach. We optimized delivery strategies, donor template designs, and component ratios to enhance HDR efficiency, significantly improving knock-in success rates. This system enables real-time fluorescent tracking and inducible protein degradation, allowing temporal control of essential viral proteins through auxin-mediated depletion. Our approach provides a powerful tool for dissecting the dynamic roles of viral proteins throughout the HCMV life cycle, facilitating a deeper understanding of viral pathogenesis and potential therapeutic targets.

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) technologies have emerged as powerful tools for precise genome editing, leading to a revolution in genetic research and biotechnology across diverse organisms including microalgae. Since the 1950s, microalgal production has evolved from initial cultivation under controlled conditions to advanced metabolic engineering to meet industrial demands. However, effective genetic modification in microalgae has faced significant challenges, including issues with transformation efficiency, limited target selection, and genetic differences between species, as interspecies genetic variation limits the use of genetic tools from one species to another. This review summarized recent advancements in CRISPR systems applied to microalgae, with a focus on improving gene editing precision and efficiency, while addressing organism-specific challenges. We also discuss notable successes in utilizing the class 2 CRISPR-associated (Cas) proteins, including Cas9 and Cas12a, as well as emerging CRISPR-based approaches tailored to overcome microalgal cellular barriers. Additionally, we propose future perspectives for utilizing CRISPR/Cas strategies in microalgal biotechnology.

Bandavirus dabieense, a single-stranded RNA virus, is the causative agent of severe fever with thrombocytopenia syndrome (SFTS), a disease associated with high fatality rates. Early and accurate diagnosis is essential for improving clinical outcomes, particularly given the limited therapeutic options and high mortality rates associated with SFTS. However, while highly sensitive, conventional diagnostic methods such as PCR and qRT-PCR require specialized laboratory facilities and trained personnel, making them impractical for rapid detection in resource-limited settings. To address these challenges, we developed a rapid and highly sensitive assay for Bandavirus dabieense detection by integrating reverse transcription loop-mediated isothermal amplification (RT-LAMP) with CRISPR/Cas12a technology. LAMP primers and guide RNA sequences were designed to target the L gene, ensuring broad detection across viral genotypes. The optimized assay demonstrated a detection limit of 5 RNA copies per reaction, showing more sensitivity than qRT-PCR, and exhibited 100% concordance with qRT-PCR results in clinical samples. Given its speed, accuracy, and field applicability, this LAMP-CRISPR/Cas12a-based assay represents a promising diagnostic tool for early SFTSV detection, particularly in resource-constrained environments where conventional molecular diagnostics are not readily available.

The oral administration of synthetic drugs can effectively reduce blood lipid levels, but adverse reactions may occur. Because of this, the hypolipidemic ability of natural products has been increasingly investigated. We evaluate the safety and hypolipidemic characteristics of a water-soluble blue pigment extracted using HPD-400 resin from the fungus Quambalaria cyanescens. Hypolipidemic ability was examined by constructing a hyperlipidemia model with different doses of blue pigment (50, 100, and 200 mg/kg. mouse body weight) for 28 d. Blue pigment purity increased from 20.32% to 70.70% following treatment with HPD-400 resin. Acute toxicity tests revealed blue pigment sourced from Q. cyanescens to have no toxic effects on mouse body weight, mortality, or behavioral characteristics. Subacute toxicity tests revealed no significant differences in food intake, body weight, or organ weights between treatment groups and controls. Histopathological examination of the liver and kidney tissues of mice administered blue pigment were normal, and serum enzyme activities and blood constituents were also within normal ranges. Blue pigment can significantly reduce the weight of mice, reduce liver and kidney damage and fat accumulation. It can also reduce total cholesterol, triglyceride and low density lipoprotein cholesterol in serum and liver tissue, and increase the level of high density lipoprotein cholesterol. Reduce the levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, creatinine, urea and uric acid in serum. Increase the activities of total superoxide dismutase, glutathione peroxidase and catalase in serum and liver tissue, reduce the content of malondialdehyde, and up-regulate liver lipase and lipoprotein lipase. Our work proves that blue pigment is nontoxic, has the function of reducing blood lipid, and can alleviate obesity-related symptoms by regulating lipid metabolism and oxidative stress.

Strains Mo2-6^T, S9, KG4-3^T, and 50Mo3-2, identified as coagulase-negative, Gram-stain-positive, halotolerant, non-motile coccoid bacteria, were isolated from traditional Korean soybean foods. Strains Mo2-6^T and S9 were both catalase- and oxidase-negative, whereas KG4-3^T and 50Mo3-2 were catalase-positive but oxidase-negative. The optimal growth conditions for Mo2-6^T and S9 were 30°C, 2% NaCl, and pH 7.0, while KG4-3^T and 50Mo3-2 grew best at 35°C, 2% NaCl, and pH 7.0. All strains contained menaquinone-7 as the predominant isoprenoid quinone, with anteiso-C_15:0 and iso-C_15:0 as the major cellular fatty acids (> 10%). Additionally, anteiso-C_13:0 was a major fatty acid in strain KG4-3^T. The DNA G + C contents of strains Mo2-6^T, S9, KG4-3^T, and 50Mo3-2 were 33.4%, 33.3%, 32.5%, and 32.7%, respectively. Phylogenetic analyses based on the 16S rRNA gene and whole-genome sequences revealed that strains Mo2-6^T and S9, as well as KG4-3^T and 50Mo3-2, formed distinct lineages within the genus Staphylococcus. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses confirmed that strains Mo2-6^T and S9, as well as KG4-3^T and 50Mo3-2, belonged to the same species. Meanwhile, dDDH and ANI values between strains Mo2-6^T and KG4-3^T, as well as comparisons with other Staphylococcus type strains, were below the species delineation thresholds, indicating they represent novel species. Based on phenotypic, chemotaxonomic, and molecular data, we propose strain Mo2-6^T as the type strain of Staphylococcus parequorum sp. nov. (=KACC 23685^T =JCM 37038^T) and strain KG4-3^T as the type strain of Staphylococcus halotolerans sp. nov. (=KACC 23684^T =JCM 37037^T).

Existing microbial engineering strategies—encompassing metabolic engineering, systems biology, and systems metabolic engineering—have significantly enhanced the potential of microbial cell factories as sustainable alternatives to the petrochemical industry by optimizing metabolic pathways. Recently, systems metabolic engineering, which integrates tools from synthetic biology, enzyme engineering, omics technology, and evolutionary engineering, has been successfully developed. By leveraging modern engineering strategies within the Design-Build-Test-Learn (DBTL) cycle framework, these advancements have revolutionized the biosynthesis of valuable compounds. This review highlights recent progress in the metabolic engineering of Corynebacterium glutamicum, a versatile microbial platform, achieved through various approaches from traditional metabolic engineering to advanced systems metabolic engineering, all within the DBTL cycle. A particular focus is placed C5 platform chemicals derived from L-lysine, one of the key amino acid production pathways of C. glutamicum. The development of DBTL cycle-based metabolic engineering strategies for this process is discussed.

Spo0A, the master regulator of sporulation initiation in Bacillus subtilis, controls over 500 genes directly or indirectly in early sporulation stages. Although the effects of Spo0A disruption on sporulation have been extensively studied, a comprehensive understanding of the genomic response throughout growth phases remain elusive. Here, we examined the transcriptomic changes in Spo0A mutant strain, R211E, and wild-type across a time-course RNA-seq to identify impacted biological processes and pathways. The R211E strain, which exhibits sporulation deficiency, was constructed using the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR associated protein (Cas)9 system, highlighting the critical role of proper Cas9 dosing in gene editing. Functional analysis of 3,010 differentially expressed genes (DEGs) showed significant alterations in sporulation, quorum sensing, metabolism, and biofilm formation. The R211E disrupted the Spo0A-AbrB regulatory pathway, reducing biofilm formation and enhancing flagellar gene expression. Up-regulated metabolic pathways, including glycolysis, histidine, and purine biosynthesis, increased cell numbers during vegetative growth. Further, the mutant displayed elevated vegetative autolysin expression, resulting in reduced cell viability in the stationary phase. We also introduce the novel potential of R211E in a recombinant protein expression system that facilitated protein release into the supernatant, providing valuable insight for future research in metabolic engineering and efficient production systems in B. subtilis.

Denitrification and dissimilatory nitrate reduction to ammonium (DNRA) were thought to be carried-out by anaerobic bacteria constrained to anoxic conditions as they use nitrate (NO₃^-) as a terminal electron acceptor instead of molecular O₂. Three soil bacilli, Neobacillus spp. strains PS2-9 and PS3-12 and Bacillus salipaludis PS3-36, were isolated from rice paddy field soil in Korea. The bacterial strains were selected as possible candidates performing aerobic denitrification and DNRA as they were observed to reduce NO₃^- and produce extracellular NH₄⁺ regardless of oxygen presence at the initial screening. Whole genome sequencing revealed that these strains possessed all the denitrification and DNRA functional genes in their genomes, including the nirK, nosZ, nirB, and nrfA genes, which were simultaneously cotranscribed under aerobic condition. The ratio between the assimilatory and dissimilatory NO₃^- reduction pathways depended on the availability of a nitrogen source for cell growth, other than NO₃^-. Based on the phenotypic and transcriptional analyses of the NO₃^- reductions, all three of the facultative anaerobic strains reduced NO₃^- likely in both assimilatory and dissimilatory pathways under both aerobic and anoxic conditions. To our knowledge, this is the first report that describes coexistence of NO₃^- assimilation, denitrification, and DNRA in a Bacillus or Neobacillus strain under aerobic condition. These strains may play a pivotal role in the soil nitrogen cycle.

The pho regulon plays a critical role in maintaining phosphate homeostasis in bacteria, with the PhoU protein functioning as a regulator that bridges the PhoB/PhoR two-component system and the PstSCAB₂ phosphate transporter. While PhoU is known to suppress PhoR autophosphorylation under high phosphate conditions via interaction with its PAS domain, its broader regulatory functions remain elusive. Here, we investigated the role of the PhoU Ala147 residue in Salmonella enterica serovar Typhimurium using a phoU^A147E substitution mutant. Bacterial two-hybrid and immunoprecipitation assays confirmed that Ala147 is essential for PhoU-PhoR PAS domain interaction, and its substitution leads to derepression of pho regulon genes, even in high phosphate conditions. This disruption impaired Salmonella survival inside macrophages and mouse virulence, demonstrating the importance of PhoU-PhoR interaction in Salmonella pathogenesis. However, unlike the phoU deletion mutant, the phoU^A147E mutant does not exhibit growth defects or polyphosphate accumulation, indicating that the PhoU-PhoR interaction is not involved in these phenotypes. Our findings reveal PhoU as a multifaceted regulator, coordinating phosphate uptake and pho regulon expression through distinct molecular interactions, and provide new insights into its role in bacterial physiology and virulence.