Journal of Microbiology

Journal Article

A PadR family transcriptional repressor regulates the transcription of chromate efflux transporter in Enterobacter sp. Z1.: Xueqi Huo, Zijie Zhou, Hongliang Liu, Gejiao Wang, Kaixiang Shi; J. Microbiol. 2024;62(5):355-365. Published online April 8, 2024; DOI: https://doi.org/10.1007/s12275-024-00117-0

23 View
0 Download

Abstract: Chromium is a prevalent toxic heavy metal, and chromate [Cr(VI)] exhibits high mutagenicity and carcinogenicity. The presence of the Cr(VI) efflux protein ChrA has been identified in strains exhibiting resistance to Cr(VI). Nevertheless, certain strains of bacteria that are resistant to Cr(VI) lack the presence of ChrB, a known regulatory factor. Here, a PadR family transcriptional repressor, ChrN, has been identified as a regulator in the response of Enterobacter sp. Z1(CCTCC NO: M 2019147) to Cr(VI). The chrN gene is cotranscribed with the chrA gene, and the transcriptional expression of this operon is induced by Cr(VI). The binding capacity of the ChrN protein to Cr(VI) was demonstrated by both the tryptophan fluorescence assay and Ni-NTA purification assay. The interaction between ChrN and the chrAN operon promoter was validated by reporter gene assay and electrophoretic mobility shift assay. Mutation of the conserved histidine residues His14 and His50 resulted in loss of ChrN binding with the promoter of the chrAN operon. This observation implies that these residues are crucial for establishing a DNA-binding site. These findings demonstrate that ChrN functions as a transcriptional repressor, modulating the cellular response of strain Z1 to Cr(VI) exposure.

Review

Host–microbial interactions in metabolic diseases: from diet to immunity: Ju-Hyung Lee , Joo-Hong Park; J. Microbiol. 2022;60(6):561-575. Published online May 5, 2022; DOI: https://doi.org/10.1007/s12275-022-2087-y

17 View
0 Download
3 Citations

Abstract: Growing evidence suggests that the gut microbiome is an important contributor to metabolic diseases. Alterations in microbial communities are associated with changes in lipid metabolism, glucose homeostasis, intestinal barrier functions, and chronic inflammation, all of which can lead to metabolic disorders. Therefore, the gut microbiome may represent a novel therapeutic target for obesity, type 2 diabetes, and nonalcoholic fatty liver disease. This review discusses how gut microbes and their products affect metabolic diseases and outlines potential treatment approaches via manipulation of the gut microbiome. Increasing our understanding of the interactions between the gut microbiome and host metabolism may help restore the healthy symbiotic relationship between them.

Journal Articles

Lentibacillus cibarius sp. nov., isolated from kimchi, a Korean fermented food: Young Joon Oh , Joon Yong Kim , Hee Eun Jo , Hyo Kyeong Park , Seul Ki Lim , Min-Sung Kwon , Hak-Jong Choi; J. Microbiol. 2020;58(5):387-394. Published online April 11, 2020; DOI: https://doi.org/10.1007/s12275-020-9507-7

19 View
0 Download
10 Citations

Abstract: Two bacterial strains designated NKC220-2T and NKC851-2 were isolated from commercial kimchi from different areas in Korea. The strains were Gram-positive, aerobic, oxidaseand catalase-positive, rod-shaped, spore-forming, non-motile, and halophilic bacteria. Both strains grew without NaCl, unlike type species in the genus Lentibacillus. The optimal pH for growth was 8.0, higher than that of the type species in the genus Lentibacillus, although growth was observed at pH 5.5–9.0. 16S rRNA gene sequence-based phylogenetic analysis indicated that the two strains (99.3–99.9% similarity) are grouped within the genus Lentibacillus and most closely related to Lentibacillus juripiscarius IS40-3T (97.4–97.6% similarity) isolated from fish sauce in Thailand. OrthoANI value between two novel strains and Lentibacillus lipolyticus SSKP1- 9T (79.5–79.6% similarity) was far lower than the species demarcation threshold. Comparative genomic analysis displayed differences between the two strains as well as among other strains belonging to Lentibacillus. Furthermore, each isolate had strain-specific groups of orthologous genes based on pangenome analysis. Genomic G + C contents of strains NKC- 220-2T and NKC851-2 were 41.9 and 42.2 mol%, respectively. The strains contained meso-diaminopimelic acid in their cell walls, and the major menaquinone was menaquinone-7. Phosphatidylglycerol, diphosphatidylglycerol, and an unidentified glycolipid, aminophospholipid, and phospholipid were the major polar lipid components of both strains. The major cellular fatty acids of the strains were anteiso-C15:0 and anteiso- C17:0. Based on phenotypic, genomic, phylogenetic, and chemotaxonomic features, strains NKC220-2T and NKC851-2 represent novel species of the genus Lentibacillus, for which the name Lentibacillus cibarius sp. nov. is proposed. The type strain is NKC220-2T (= KACC 21232T = JCM 33390T).

Differences in the gut microbiota between Cercopithecinae and Colobinae in captivity: Zongjin Huan , Yongfang Yao , Jianqiu Yu , Hongwei Chen , Meirong Li , Chaojun Yang , Bo Zhao , Qingyong Ni , Mingwang Zhang , Meng Xie , Huailiang Xu; J. Microbiol. 2020;58(5):367-376. Published online March 28, 2020; DOI: https://doi.org/10.1007/s12275-020-9493-9

18 View
0 Download
10 Citations

Abstract: The gut microbiome of captive primates can provide a window into their health and disease status. The diversity and composition of gut microbiota are influenced by not only host phylogeny, but also host diet. Old World monkeys (Cercopithecidae) are divided into two subfamilies: Cercopithecinae and Colobinae. The diet and physiological digestive features differ between these two subfamilies. Accordingly, highthroughput sequencing was used to examine gut microbiota differences between these two subfamilies, using data from 29 Cercopithecinae individuals and 19 Colobinae individuals raised in captivity. Through a comparative analysis of operational taxonomic units (OTUs), significant differences in the diversity and composition of gut microbiota were observed between Cercopithecinae and Colobinae. In particular, the gut microbiota of captive Old World monkeys clustered strongly by the two subfamilies. The Colobinae microbial diversity was higher than that of Cercopithecinae. Additionally, Firmicutes, Lactobacillaceae, Veillonellaceae, and Prevotella abundance were higher in Cercopithecinae, while Bacteroidetes, Ruminococcaceae, Christensenellaceae, Bacteroidaceae, and Acidaminococcaceae abundance were higher in Colobinae. PICRUSt analysis revealed that the predicted metagenomes of metabolic pathways associated with proteins, carbohydrates, and amino acids were significantly higher in Colobinae. In the context of host phylogeny, these differences between Cercopithecinae and Colobinae could reflect adaptations associated with their respective diets. This well-organized dataset is a valuable resource for future related research on primates and gut microbiota. Moreover, this study may provide useful insight into animal management practices and primate conservation.

Jejubacter calystegiae gen. nov., sp. nov., moderately halophilic, a new member of the family Enterobacteriaceae, isolated from beach morning glory: Lingmin Jiang , Dexin Wang , Jung-Sook Lee , Dae-Hyuk Kim , Jae Cheol Jeong , Cha Young Kim , Suk Weon Kim , Jiyoung Lee; J. Microbiol. 2020;58(5):357-366. Published online March 27, 2020; DOI: https://doi.org/10.1007/s12275-020-9294-1

15 View
0 Download
5 Citations

Abstract: Strain KSNA2T, a Gram-negative, moderately halophilic, facultatively anaerobic, motile, rod-shaped bacterium, was isolated from the surface-sterilized stem tissue of a beach morning glory (Calystegia soldanella) plant in Chuja Island, Jejudo, Republic of Korea. Phylogenetic analysis based on 16S rRNA gene and whole-genome sequences revealed that strain KSNA2T formed a distinct lineage within the family Enterobacteriaceae, with the highest 16S rRNA gene sequence similarity to Izhakiella australiensis KCTC 72143T (96.2%) and Izhakiella capsodis KCTC 72142T (96.0%), exhibited 95.5– 95.9% similarity to other genera in the family Enterobacteriaceae and Erwiniaceae. Conserved signature indels analysis elucidated that strain KSNA2T was delimited into family Enterobacteriaceae. KSNA2T genome comprises a circular chromosome of 5,182,800 bp with 56.1% G + C content. Digital DNA-DNA relatedness levels between strain KSNA2T and 18 closely related species were 19.3 to 21.1%. Average nucleotide identity values were between 72.0 and 76.7%. Growth of strain KSNA2T was observed at 4 to 45°C (optimum, 25°C) and pH 5.0 to 12.0 (optimum, pH 7.0) in the presence of 0 to 11% (w/v) NaCl (optimum, 0–7%). The major cellular fatty acids (> 10%) were C16:0 followed by summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C17:0 cyclo, and C14:0. The major isoprenoid quinone was ubiquinone-8 (Q-8). With combined phylogenetic, genomic, phenotypic, and chemotaxonomic features, strain KSNA2T represents a novel species of a new genus in the family Enterobacteriaceae, for which the name Jejubacter calystegiae gen. nov., sp. nov. is proposed. The type strain is KSNA2T (= KCTC 72234T = CCTCC AB 2019098T).

First
Prev
Page of 1
Next
Last

Search