Journal of General and Applied Microbiology最新文献

Effect of glycoside hydrolase 18 chitinase on alternately β-1,4-linked glucose and N-acetylglucosamine derived from the sulfur-oxidizing bacterium Thiothrix nivea. 糖苷水解酶18几丁质酶对硫氧化菌中β-1,4-连接葡萄糖和n -乙酰氨基葡萄糖交替产生的影响。

IF 0.6 4区生物学

Journal of General and Applied Microbiology Pub Date : 2026-10-02 DOI: 10.2323/jgam.2026.09.001

Naoki Matsunaga, Keiko Kondo, Masato Katahira, Minoru Takeda

{"title":"Effect of glycoside hydrolase 18 chitinase on alternately β-1,4-linked glucose and N-acetylglucosamine derived from the sulfur-oxidizing bacterium Thiothrix nivea.","authors":"Naoki Matsunaga, Keiko Kondo, Masato Katahira, Minoru Takeda","doi":"10.2323/jgam.2026.09.001","DOIUrl":"https://doi.org/10.2323/jgam.2026.09.001","url":null,"abstract":"The filamentous sulfur-oxidizing bacterium Thiothrix nivea produces glucosaminoglucan (GG), which is β-1,4-linked copolymer of glucose and glucosamine. GG is a major component of the sheath which covers the bacterial filament, and the bacterium uses CO2 and organic acids as carbon sources in the presence of H2S. Similar to chitin, N-acetylated GG (NGG) can be degraded by lysozyme. However, it has not yet been confirmed whether NGG can be degraded by chitinase. Glycoside hydrolase 18 (GH18) chitinase is present in mammals and is produced by various microorganisms. In this study, the degradation of NGG by GH18 chitinase was investigated. When GH18 chitinase was added to the NGG suspension, a decrease in turbidity and an increase in reducing power were observed, indicating that it can degrade NGG. HPLC analysis and Nuclear magnetic resonance spectroscopy revealed that the enzyme degrades NGG into a specific disaccharide β-Glc-(1→4)-GlcNAc. Accordingly, it was found that GH18 chitinase hydrolyzes the GlcNAc→Glc linkage but not the Glc→GlcNAc linkage. The NGG degradation rate was much lower than that of chitin. Hence, NGG was recognized as a material with better biological durability than that of chitin. NGG-chitin composites with different NGG contents were prepared, and as the NGG content increased, the susceptibility of the hydrogel to chitinase decreased. Importantly, this study proposes a novel method for controlling the stability of chitin hydrogels using GH18 chitinase and enhances current understanding of the enzyme.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2026-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149110686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparative analysis of bacterial communities in traditional fermented food: Nezushi from Gifu Prefecture and izushi-style narezushi from across Japan. 传统发酵食品中细菌群落的比较分析：岐阜县的neizhi和日本各地的izizhi式narezushi。

IF 0.6 4区生物学

Journal of General and Applied Microbiology Pub Date : 2026-09-04 Epub Date: 2026-05-26 DOI: 10.2323/jgam.2026.05.001

Mitsuyo Hori, Chisa Ohtsubo, Kohei Nakamura, Masahiro Hirata, Masaya Shimada, Tomoyuki Nakagawa

{"title":"Comparative analysis of bacterial communities in traditional fermented food: Nezushi from Gifu Prefecture and izushi-style narezushi from across Japan.","authors":"Mitsuyo Hori, Chisa Ohtsubo, Kohei Nakamura, Masahiro Hirata, Masaya Shimada, Tomoyuki Nakagawa","doi":"10.2323/jgam.2026.05.001","DOIUrl":"10.2323/jgam.2026.05.001","url":null,"abstract":"Narezushi is a traditional Japanese fermented food made from fish and rice. Nezushi is a regional variety of izushi-style narezushi produced in the Hida (Gero) and Oku-Mino (Gujo) regions of Gifu Prefecture. In this study, nezushi was analyzed to clarify its bacterial communities using both culture-dependent and culture-independent approaches. Nezushi (Gero) was dominated almost exclusively by Latilactobacillus sakei, whereas nezushi (Gujo) showed greater diversity with Latilactobacillus sakei and Leuconostoc lactis. Izushi (Tokachi) closely resembled nezushi (Gero), while izushi (Ishikari) resembled nezushi (Gujo). In contrast, kabura‑zushi (Kanazawa) exhibited a distinct community dominated by Leuconostoc spp. These results indicate that psychrotrophic lactic acid bacteria, primarily Latilactobacillus sakei and Leuconostoc spp., drive fermentation in izushi‑style narezushi, while regional processing conditions shape microbial composition. This study provides the first microbiological characterization of nezushi, revealing previously unrecognized features of its fermentation ecology.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":" ","pages":"70-73"},"PeriodicalIF":0.6,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147982203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Choline-Responsive Band-Pass gene circuit without transcriptional cascades. 无转录级联的胆碱反应带通基因回路。

IF 0.6 4区生物学

Journal of General and Applied Microbiology Pub Date : 2026-09-04 Epub Date: 2026-04-29 DOI: 10.2323/jgam.2026.04.001

Yoshiki Takemura, Haruka Satoh, Kenta Harada, Shinichiro Suzuki, Daisuke Umeno

{"title":"A Choline-Responsive Band-Pass gene circuit without transcriptional cascades.","authors":"Yoshiki Takemura, Haruka Satoh, Kenta Harada, Shinichiro Suzuki, Daisuke Umeno","doi":"10.2323/jgam.2026.04.001","DOIUrl":"10.2323/jgam.2026.04.001","url":null,"abstract":"Band-pass filters, which selectively transmit signals within a defined range of input magnitudes, are fundamental components of signal-processing systems. In cellular gene circuits, band-pass behavior has likewise been pursued as a mean to implement complex signal-processing functions. However, previously reported genetic band-pass circuits have typically relied not only on a large number of regulatory components but also on transcriptional cascades involving multiple transcription factors, resulting in long DNA sequences and increased circuit complexity. Here, we first propose a band-pass gene circuit that operates without transcriptional cascades. By co-expressing two variants of the transcription factor BetI that exhibit opposite input-response behaviors-one acting as an inducer-dependent activator and the other as an inducer-dependent repressor-band-pass filtering is achieved solely through differential tuning of their inducer sensitivities. This minimal architecture enables gene expression only within a specific range of intracellular choline concentrations. Furthermore, we demonstrate that this cascade-free band-pass circuit can be exploited to generate spatial expression patterns in Escherichia coli populations in response to a choline diffusion gradient, illustrating its utility for pattern formation in multicellular contexts.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":" ","pages":"41-48"},"PeriodicalIF":0.6,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147773344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Acetylcholine responsiveness of the BetI regulatory system in Escherichia coli. 大肠杆菌BetI调控系统对乙酰胆碱的响应性。

IF 0.6 4区生物学

Journal of General and Applied Microbiology Pub Date : 2026-09-04 Epub Date: 2026-05-29 DOI: 10.2323/jgam.2026.05.003

Haruka Satoh, Kenta Harada, Yoshiki Takemura, Shinichiro Suzuki, Daisuke Umeno

引用次数: 0

Polyamines induce prolonged maintenance of stationary phase turbidity in coagulase-negative Staphylococcus. 多胺诱导凝固酶阴性葡萄球菌长时间维持固定相浊度。

IF 0.6 4区生物学

Journal of General and Applied Microbiology Pub Date : 2026-09-04 Epub Date: 2026-05-11 DOI: 10.2323/jgam.2026.04.002

Osamu Funatsu, Hiroko Ishii, Reiko Shimatsu, Yutaka Shimokawa, Akihiko Asahina, Itaru Dekio

引用次数: 0

Identification of a plastid-targeted RecQ-like helicase in the red alga Cyanidioschyzon merolae. 红藻叶绿体靶向recq样解旋酶的鉴定。

IF 0.6 4区生物学

Journal of General and Applied Microbiology Pub Date : 2026-09-04 Epub Date: 2026-05-28 DOI: 10.2323/jgam.2026.05.002

Shoko Kawato, Minori Ebihara, Yui Mizuki, Takayuki Fujiwara, Shin-Ya Miyagishima, Yusuke Kobayashi

引用次数: 0

Verification of optimal pre-enrichment culture inoculum size for tetrathionate broth and selenite broth to isolate Salmonella enterica by spike test and field trial. 通过刺钉试验和田间试验验证了四硫代酸肉汤和亚硒酸肉汤分离肠炎沙门氏菌的最佳预富集培养接种量。

IF 0.6 4区生物学

Journal of General and Applied Microbiology Pub Date : 2026-09-04 DOI: 10.2323/jgam.2026.08.002

Shiho Oyama, Hiroto Kitamura, Shunta Funada, Jun Hakozaki, Masatoshi Fujihara

{"title":"Verification of optimal pre-enrichment culture inoculum size for tetrathionate broth and selenite broth to isolate Salmonella enterica by spike test and field trial.","authors":"Shiho Oyama, Hiroto Kitamura, Shunta Funada, Jun Hakozaki, Masatoshi Fujihara","doi":"10.2323/jgam.2026.08.002","DOIUrl":"https://doi.org/10.2323/jgam.2026.08.002","url":null,"abstract":"The isolation efficiency of Salmonella enterica using selective enrichment media varies depending on culture conditions. Tetrathionate broth (TTB) and selenite broth (SB) differ in selectivity and growth support, yet practical guidance on optimizing their use remains limited. To identify appropriate conditions for improving recovery, we first conducted a spike test in which a defined amount of S. enterica was added to Salmonella negative cattle feces. TTB showed improved isolation rates when the inoculum size was reduced and the incubation period was extended, indicating that each factor independently contributed to recovery. In contrast, SB exhibited enhanced recovery when a smaller inoculum was combined with an incubation period appropriate for that inoculum size. We then validated these observations using naturally contaminated chicken liver, pig feces, and crow droppings. After pre‑enrichment, samples were inoculated into TTB, SB, modified semi‑solid Rappaport agar for stab culture (MSRAsc), and Rappaport-Vassiliadis broth under various culture conditions. Although results varied among sample types, TTB and SB generally showed improved isolation rates when cultured under the optimized conditions. MSRAsc achieved the highest overall recovery, but some strains, likely sensitive to dyes, failed to grow. These results indicate that although optimizing TTB and SB enhances isolation efficiency, no single medium is sufficient to recover a broad range of serovars. Therefore, a combined approach using dye‑free TTB alongside MSRAsc is recommended, and SB should also be used when strains exhibiting poor growth in other selective media are suspected.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148900633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Developing an assay system for screening inhibitors of Hfq-mediated RNA metabolism. 开发筛选hfq介导的RNA代谢抑制剂的检测系统。

IF 0.6 4区生物学

Journal of General and Applied Microbiology Pub Date : 2026-08-26 DOI: 10.2323/jgam.2026.08.001

Ayako Takada, Masaaki Wachi

{"title":"Developing an assay system for screening inhibitors of Hfq-mediated RNA metabolism.","authors":"Ayako Takada, Masaaki Wachi","doi":"10.2323/jgam.2026.08.001","DOIUrl":"https://doi.org/10.2323/jgam.2026.08.001","url":null,"abstract":"Hfq is an RNA chaperone conserved across diverse bacterial lineages that regulates gene expression by facilitating the pairing of small RNAs with their target mRNAs. It influences both the translation and stability of specific transcripts, thereby contributing to complex post-transcriptional regulatory networks. We have previously shown that overproduction of Hfq inhibits cell division by suppressing the expression of the essential cell division protein FtsZ. Based on this observation, we developed a novel antibiotic screening system using an Escherichia coli strain harboring an IPTG-inducible hfq gene to identify compounds that interfere with Hfq-mediated RNA metabolism. We tested representative inhibitors of DNA synthesis, protein synthesis, and cell wall synthesis; however, none restored colony formation. In contrast, rifampicin, an inhibitor of RNA polymerase, restored colony formation, as expected for a compound interfering with Hfq function. Sublethal concentrations of rifampicin restored colony formation of the Hfq-overproducing cells. Western blot analysis revealed that Hfq expression levels decreased upon rifampicin treatment, indicating that rifampicin was a false-positive hit. To eliminate such false-positive hits, a rifampicin-resistant rpoB mutation was introduced into the indicator strain. As expected, rifampicin did not restore growth of the rifampicin-resistant rpoB strain. This assay provides a useful platform for identifying compounds that interfere with Hfq-mediated RNA metabolism.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148829193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bioinformatics analysis of extracellular glycosyl hydrolases mined from the genome of Halophilic Meridianimaribacter sp. CL38. 嗜盐性Meridianimaribacter sp. CL38基因组胞外糖基水解酶的生物信息学分析。

IF 0.6 4区生物学

Journal of General and Applied Microbiology Pub Date : 2026-08-21 DOI: 10.2323/jgam.2026.07.001

Zhen Wei Tan, Muhamad Naim Abd Malek, Kah Yaw Ee, Wei Lun Lim, Chun Shiong Chong, Ming Quan Lam

{"title":"Bioinformatics analysis of extracellular glycosyl hydrolases mined from the genome of Halophilic Meridianimaribacter sp. CL38.","authors":"Zhen Wei Tan, Muhamad Naim Abd Malek, Kah Yaw Ee, Wei Lun Lim, Chun Shiong Chong, Ming Quan Lam","doi":"10.2323/jgam.2026.07.001","DOIUrl":"https://doi.org/10.2323/jgam.2026.07.001","url":null,"abstract":"Biological pre-treatment of lignocellulosic waste is crucial for efficient fermentation in second-generation biofuel production. Halophilic bacteria produce glycosyl hydrolases with enhanced stability for industrial application. This study aimed to characterise putative glycosyl hydrolases (cellulases and hemicellulases) encoded in the genome of the halophilic bacterium Meridianimaribacter sp. CL38 using bioinformatic approaches, in order to address the scarcity of structural information for this genus. Four putative glycosyl hydrolases (GH9, GH3, GH144 and GH16) were analysed, focusing on their functional domains and structural properties. Phylogenetic analysis indicated a close relationship with other members of the Flavobacteriaceae family. Structural analyses revealed significant predicted halophilic and thermostable properties, suggesting these putative enzymes may endure industrial conditions. This study provides insights into putative glycosyl hydrolase candidates for efficient lignocellulosic waste pre-treatment.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148808658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Development of a small mobilizable plasmid system: A foundation for genetic engineering of Bacillus subtilis strains. 小型可移动质粒系统的开发：枯草芽孢杆菌菌株基因工程的基础。

IF 0.6 4区生物学

Journal of General and Applied Microbiology Pub Date : 2026-07-06 DOI: 10.2323/jgam.2026.06.005

Takahiro Morita, Wakana Suda, Mitsuhiro Itaya, Kei Asai

引用次数: 0