Journal of Microbiology

Journal Article

Comprehensive Analysis of Gut Microbiota Alteration in the Patients and Animal Models with Polycystic Ovary Syndrome: Jing Zhou , Xuemei Qiu , Xuejing Chen , Sihan Ma , Zhaoyang Chen , Ruzhe Wang , Ying Tian , Yufan Jiang , Li Fan , Jingjie Wang; J. Microbiol. 2023;61(9):821-836. Published online October 12, 2023; DOI: https://doi.org/10.1007/s12275-023-00079-9

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Abstract: Polycystic ovary syndrome (PCOS) is a common disease of endocrine–metabolic disorder, and its etiology remains largely unknown. The gut microbiota is possibly involved in PCOS, while the association remains unclear. The comprehensive analysis combining gut microbiota with PCOS typical symptoms was performed to analyze the role of gut microbiota in PCOS in this study. The clinical patients and letrozole-induced animal models were determined on PCOS indexes and gut microbiota, and fecal microbiota transplantation (FMT) was conducted. Results indicated that the animal models displayed typical PCOS symptoms, including disordered estrous cycles, elevated testosterone levels, and ovarian morphological change; meanwhile, the symptoms were improved after FMT. Furthermore, the microbial diversity exhibited disordered, and the abundance of the genus Ruminococcus and Lactobacillus showed a consistent trend in PCOS rats and patients. The microbiota diversity and several key genera were restored subjected to FMT, and correlation analysis also supported relevant conclusions. Moreover, LEfSe analysis showed that Gemmiger, Flexispira, and Eubacterium were overrepresented in PCOS groups. Overall, the results indicate the involvement of gut microbiota in PCOS and its possible alleviation of endocrinal and reproductive dysfunctions through several special bacteria taxa, which can function as the biomarker or potential target for diagnosis and treatment. These results can provide the new insights for treatment and prevention strategies of PCOS.

Review

Envelope‑Stress Sensing Mechanism of Rcs and Cpx Signaling Pathways in Gram‑Negative Bacteria: Seung-Hyun Cho , Kilian Dekoninck , Jean-Francois Collet; J. Microbiol. 2023;61(3):317-329. Published online March 9, 2023; DOI: https://doi.org/10.1007/s12275-023-00030-y

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9 Citations

Abstract: The global public health burden of bacterial antimicrobial resistance (AMR) is intensified by Gram-negative bacteria, which have an additional membrane, the outer membrane (OM), outside of the peptidoglycan (PG) cell wall. Bacterial twocomponent systems (TCSs) aid in maintaining envelope integrity through a phosphorylation cascade by controlling gene expression through sensor kinases and response regulators. In Escherichia coli, the major TCSs defending cells from envelope stress and adaptation are Rcs and Cpx, which are aided by OM lipoproteins RcsF and NlpE as sensors, respectively. In this review, we focus on these two OM sensors. β-Barrel assembly machinery (BAM) inserts transmembrane OM proteins (OMPs) into the OM. BAM co-assembles RcsF, the Rcs sensor, with OMPs, forming the RcsF-OMP complex. Researchers have presented two models for stress sensing in the Rcs pathway. The first model suggests that LPS perturbation stress disassembles the RcsF-OMP complex, freeing RcsF to activate Rcs. The second model proposes that BAM cannot assemble RcsF into OMPs when the OM or PG is under specific stresses, and thus, the unassembled RcsF activates Rcs. These two models may not be mutually exclusive. Here, we evaluate these two models critically in order to elucidate the stress sensing mechanism. NlpE, the Cpx sensor, has an N-terminal (NTD) and a C-terminal domain (CTD). A defect in lipoprotein trafficking
results
in NlpE retention in the inner membrane, provoking the Cpx response. Signaling requires the NlpE NTD, but not the NlpE CTD; however, OM-anchored NlpE senses adherence to a hydrophobic surface, with the NlpE CTD playing a key role in this function.

Journal Articles

Fungal Catastrophe of a Specimen Room: Just One Week is Enough to Eradicate Traces of Thousands of Animals: Ji Seon Kim , Yoonhee Cho , Chang Wan Seo , Ki Hyung Park , Shin Nam Yoo , Jun Won Lee , Sung Hyun Kim , Wonjun Lee , Young Woon Lim; J. Microbiol. 2023;61(2):189-197. Published online February 6, 2023; DOI: https://doi.org/10.1007/s12275-023-00017-9

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Abstract: Indoor fungi obtain carbon sources from natural sources and even recalcitrant biodegradable materials, such as plastics and synthetic dye. Their vigorous activity may have negative consequences, such as structural damage to building materials or the destruction of precious cultural materials. The animal specimen room of the Seoul National University stocked 36,000 animal resources that had been well-maintained for over 80 years. Due to abandonment without the management of temperature and humidity during the rainy summer season, many stuffed animal specimens had been heavily colonized by fungi. To investigate the fungal species responsible for the destruction of the historical specimens, we isolated fungi from the stuffed animal specimens and identified them at the species level based on morphology and molecular analysis of the β-tubulin (BenA) gene. A total of 365 strains were isolated and identified as 26 species in Aspergillus (10 spp.), Penicillium (14 spp.), and Talaromyces (2 spp.). Penicillium brocae and Aspergillus sydowii were isolated from most sections of the animal specimens and have damaged the feathers and beaks of valuable specimens. Our findings indicate that within a week of mismanagement, it takes only a few fungal species to wipe out the decades of history of animal diversity. The important lesson here is to prevent this catastrophe from occurring again through a continued interest, not to put all previous efforts to waste.

Promoter exchange of the cryptic nonribosomal peptide synthetase gene for oligopeptide production in Aspergillus oryzae: Chanikul Chutrakul , Sarocha Panchanawaporn , Sukanya Jeennor , Jutamas Anantayanon , Kobkul Laoteng; J. Microbiol. 2022;60(1):47-56. Published online November 9, 2021; DOI: https://doi.org/10.1007/s12275-022-1442-3

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Abstract: Oligopeptides with functional activities are of current interest in the nutraceutical and medical sectors. The development of the biosynthetic process of oligopeptides through a nonribosomal peptide synthetase (NRPS) system has become more challenging. To develop a production platform for nonribosomal peptides (NRPs), reprogramming of transcriptional regulation of the acv gene encoded ACV synthetase (ACVS) was implemented in Aspergillus oryzae using the CRISPRCas9 system. Awakening silent acv expression was successfully achieved by promoter substitution. Among the three exchanged promoters, AoPgpdA, AoPtef1, and PtPtoxA, the replacement of the native promoter with AoPgpdA led to the highest ACV production in A. oryzae. However, the ACV production of the AoPGpdA strain was also dependent on the medium composition, in which urea was the best nitrogen source, and a C:N ratio of 20:1 was optimal for tripeptide production. In addition to cell growth, magnesium ions are an essential element for ACV production and might participate in ACVS activity. It was also found that ACV was the growthassociated product of the engineered strain that might be a
result
of constitutive transcriptional control by the AoPgpdA promoter. This study offers a potential strategy for nonribosomal ACV production using the fungal system, which is applicable for redesigning bioactive oligopeptides with industrial relevance.

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