{"title":"Promoter Sequences Do Not Solely Govern nosZ Expression Differences between Bradyrhizobium ottawaense and B. diazoefficiens.","authors":"Sawa Wasai-Hara, Yoshikazu Shimoda, Hisayuki Mitsui, Shusei Sato, Haruko Imaizumi-Anraku, Kiwamu Minamisawa","doi":"10.1264/jsme2.ME25079","DOIUrl":"10.1264/jsme2.ME25079","url":null,"abstract":"<p><p>Nitrous oxide (N<sub>2</sub>O) is a potent greenhouse gas, and the enzyme Nos catalyzes its reduction to dinitrogen (N<sub>2</sub>). Bradyrhizobium ottawaense exhibits strong N<sub>2</sub>O-reducing activity with high nosZ expression. To investigate whether promoter sequences affect nosZ expression, we constructed reciprocal promoter-swapped mutants between B. ottawaense and B. diazoefficiens. The swapping of promoters did not significantly affect expression levels. B. ottawaense mutants maintained approximately 200-fold higher expression levels than B. diazoefficiens, and the introduction of the B. ottawaense promoter into B. diazoefficiens did not increase expression levels. Therefore, the present results indicate that promoter sequence differences are not the primary factor affecting nosZ expression, suggesting regulation by other factors.</p>","PeriodicalId":18482,"journal":{"name":"Microbes and Environments","volume":"41 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12999732/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147355663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Inoculation with Bradyrhizobium ottawaense Effectively Reduces N<sub>2</sub>O Emissions from Degraded Soybean Nodules in Andosols Dominated by nosZ-lacking Bradyrhizobia.","authors":"Misa Tsubokura, Shintaro Hara, Tsubasa Ohbayashi, Masanori Takeda, Yuma Sasaki, Haruka Ukita, Miho Fujimori, Kaori Kakizaki, Manabu Itakura, Kiwamu Minamisawa, Hiroko Akiyama","doi":"10.1264/jsme2.ME26022","DOIUrl":"10.1264/jsme2.ME26022","url":null,"abstract":"<p><p>Nitrous oxide (N<sub>2</sub>O) is a potent greenhouse gas, and its largest anthropogenic source is agricultural soils. In these soils, N<sub>2</sub>O emissions are produced from nitrogen fertilization and nitrogen-rich crop residues, such as soybean nodules. Previous studies demonstrated that inoculation with Bradyrhizobium diazoefficiens possessing the N<sub>2</sub>O reductase gene (nosZ) effectively mitigated N<sub>2</sub>O emissions from soybean fields at harvest. More recently, Bradyrhizobium ottawaense, which exhibits higher nosZ expression, reduced N<sub>2</sub>O emissions more effectively than B. diazoefficiens during the degradation of soybean nodules formed under sterile vermiculite conditions. Although the effects of inoculation with B. ottawaense have subsequently been exami-ned under natural soil conditions, it remains unclear whether these effects are maintained across different soil types and soybean cultivars. Therefore, we herein investigated the effects of inoculation with B. ottawaense on its competitiveness and N<sub>2</sub>O emissions in pot experiments using two field soils (Andosol and Fluvisol) and three Japanese commercial soybean cultivars ('Hatayutaka', 'Yukihomare R', and 'Satonohohoemi'). The results demonstrated that inoculation with B. ottawaense significantly increased higher nodule occupancy of the inoculant strain compared with the non-inoculated controls in the two field soils. Moreover, B. ottawaense tended to reduce N<sub>2</sub>O emissions in Andosol dominated by nosZ-lacking bradyrhizobia, regardless of the soybean cultivar. No significant N<sub>2</sub>O-reducing effects were observed in Fluvisol dominated by nosZ-possessing bradyrhizobia. Collectively, these results suggest the applicability of inoculation with B. ottawaense to diverse soybean cultivars and its effectiveness in mitigating N<sub>2</sub>O emissions from soybean fields in which indigenous nosZ-lacking bradyrhizobial populations are dominant, such as Andosols.</p>","PeriodicalId":18482,"journal":{"name":"Microbes and Environments","volume":"41 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13659342/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148920308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liang Feng, Jia Xing Loi, Joana Séneca, Petra Pjevac, Faidzul Hakim Adnan, Gek Cheng Ngoh, Bee Chin Khor, Alijah Mohd Aris, Mamoru Oshiki, Holger Daims, Adeline Seak May Chua
{"title":"Nitrifying Communities in Biological Nitrogen Removal Processes at Tropical Municipal Wastewater Treatment Plants.","authors":"Liang Feng, Jia Xing Loi, Joana Séneca, Petra Pjevac, Faidzul Hakim Adnan, Gek Cheng Ngoh, Bee Chin Khor, Alijah Mohd Aris, Mamoru Oshiki, Holger Daims, Adeline Seak May Chua","doi":"10.1264/jsme2.ME25036","DOIUrl":"10.1264/jsme2.ME25036","url":null,"abstract":"<p><p>Nitrifying communities in activated sludge play a crucial role in biological nitrogen removal processes in municipal wastewater treatment plants. While extensive research has been conducted in temperate regions, limited information is available on nitrifiers in tropical regions. The present study investigated all currently known nitrifying communities in two full-scale municipal wastewater treatment plants in Malaysia operated under low-dissolved oxygen (DO) (0.2-0.7 mg DO L<sup>-1</sup>) or high-DO (2.0-5.5 mg DO L<sup>-1</sup>) conditions at 30°C. The core nitrifiers in the municipal wastewater treatment plants were Nitrosomonas (ammonia-oxidizing bacteria, AOB), Nitrospira (nitrite-oxidizing or complete ammonia-oxidizing, comammox, bacteria), and ammonia-oxidizing archaea (AOA) as identified by a 16S rRNA gene amplicon sequencing ana-lysis and corroborated by 16S rRNA-targeted fluorescence in situ hybridization. A quantitative polymerase chain reaction (qPCR) targeting ammonia monooxygenase subunit A (amoA) genes revealed stable populations of comammox Nitrospira and AOB in both wastewater treatment plants. AOA were detected in only one of the plants and their population sizes fluctuated, with higher temporary abundance under high-DO conditions. These results provide important insights into the composition and dynamics of nitrifying communities in tropical municipal wastewater treatment plants.</p>","PeriodicalId":18482,"journal":{"name":"Microbes and Environments","volume":"40 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12501877/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145033697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ammonia Oxidation Property of Soils on the Glacier Foreland of Austre Brøggerbreen, Svalbard: Response to Open-top Chamber Experiments.","authors":"Kentaro Hayashi, Keisuke Ono, Yukiko Tanabe, Masahito Hayatsu, Kanako Tago, Tsubasa Ohbayashi, Yong Wang, Luciano Nobuhiro Aoyagi, Masaki Uchida","doi":"10.1264/jsme2.ME25058","DOIUrl":"10.1264/jsme2.ME25058","url":null,"abstract":"<p><p>Recent warming and glacier retreat in the Svalbard Archipelago, part of the Arctic cryosphere, have become increasingly evident. The present study investigated the foreland of Austre Brøggerbreen near Ny-Ålesund to clarify how soil nitrification responds to changing conditions. Two sites, exposed for different periods following glacier retreat, were compared. A manipulation experiment using open-top chambers (OTCs) and homogenized initial soil conditions was conducted to assess the effects of site differences, the OTC treatment, soil depth, and interannual variations on soil and nitrification properties. Although the OTC treatment slightly increased soil temperature and moisture, its overall effect on soil properties, ammonia oxidation potential (AOP), and microbial properties was negligible. In contrast, homogenization markedly increased total nitrogen at both sites and temporarily boosted AOPs for two years before levels returned to baseline. Site 2, exposed for longer, contained more soil nitrogen and showed higher AOP than Site 1. For example, in 2015, AOPs at 10°C were 3.5 and 2.4 ng N g<sup>-1</sup> dry soil h<sup>-1</sup> at Sites 2 and 1, respectively. Ammonia-oxidizing bacteria (AOB) and archaea (AOA) were both more abundant at Site 2, although AOB clearly dominated at both sites. While AOB-amoA operational taxonomic units (OTUs) were mostly shared between sites, community compositions differed: OTU2 was prevalent at Site 1, but minor at Site 2. OTU2 may act as a pioneer taxon that declines in later stages, or its pattern may reflect site-specific soil conditions. A phylogenetic anal-ysis showed that OTU2 and OTU3 belonged to Cluster ME found near Mount Everest.</p>","PeriodicalId":18482,"journal":{"name":"Microbes and Environments","volume":"40 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12727203/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145557208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Genetic Diversity of Endospore-forming Nitrogen-fixing Bacteria and Their Future Application as Biofertilizers in the Central Dry Zone of Myanmar.","authors":"Ya Maon Phoo, Koki Toyota, Yu Yu Min","doi":"10.1264/jsme2.ME25033","DOIUrl":"10.1264/jsme2.ME25033","url":null,"abstract":"<p><p>In Myanmar, the application of both nitrogen-based chemical fertilizers and biofertilizers is limited and this low input has caused poor agricultural yields. The present study aimed to isolate indigenous endospore-forming nitrogen-fixing bacteria (EFNFB) and examine their potential for co-inoculation with agricultural waste. A total of 387 isolates were obtained from 42 different soil samples in the central dry zone of Myanmar using nitrogen-free Rennie medium. Nitrogen-fixing activity (NFA) assessed with the acetylene reduction assay was positive in 102 isolates. A phylogenetic ana-lysis based on 16S rRNA sequences identified 25 different species, including the genera Paenibacillus, Priestia, Bacillus, Brevibacillus, Sporolactobacillus, Niallia, and Neobacillus. Among these genera, Paenibacillus spp. was the predominant genus, comprising 51 isolates (64%) across 16 different species (64%) that were prevalent in soils rotated with rice and pulses. Paenibacillus spp. showed different NFA levels in Rennie medium. Eleven species belonging to different genera had not been previously documented as nitrogen-fixing bacteria. NFA levels were evaluated in soil inoculated with EFNFB and rice straw or mung bean residue. The results obtained demonstrated that NFA levels were dependent on isolates and the type of agricultural waste. NFA in soil was significantly increased by inoculations with some isolates, suggesting their potential as biofertilizers. The inoculation of Priestia aryabhattai S10 with rice straw or mung bean resulted in significantly higher NFA levels in soil. These results indicate the potential of EFNFB as biofertilizer inoculants in Myanmar.</p>","PeriodicalId":18482,"journal":{"name":"Microbes and Environments","volume":"40 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12727198/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145756999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High-pressure Methanogenesis Reveals Metabolic Adaptation to Dissolved CO<sub>2</sub> Limitation.","authors":"Taiki Katayama, Hideyoshi Yoshioka, Masaru K Nobu","doi":"10.1264/jsme2.ME25066","DOIUrl":"10.1264/jsme2.ME25066","url":null,"abstract":"<p><p>This study investigated the effects of elevated hydrostatic pressure on methane production and gene expression in a hydrogenotrophic methanogen isolated from subseafloor sediments at biogenic gas hydrate sites, with a focus on the implications of CO<sub>2</sub> availability. Using high-pressure cultivation, the methane production rate decreased by 15% at 25 MPa, while a transcriptomic anal-ysis revealed the marked up-regulation of methyl-coenzyme M reductase and ATP synthase. These results suggest that methanogens compensate for pressure-driven constraints on CO<sub>2</sub> utilization by increasing the expression of key methanogenic enzymes, underscoring the overlooked role of CO<sub>2</sub> in deep biosphere microbial processes.</p>","PeriodicalId":18482,"journal":{"name":"Microbes and Environments","volume":"40 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12727201/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145757038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fusarium Fungi Produce Nitrous Oxide (N<sub>2</sub>O) from Nitrite (NO<sub>2</sub><sup>-</sup>) in a Model Pot System Simulating the Soybean Rhizosphere.","authors":"Makoto Moriuchi, Keiichi Kuzunuki, Fumio Ikenishi, Reiko Sameshima, Akira Nakagiri, Sakae Toyoda, Chie Katsuyama, Kaori Kakizaki, Manabu Itakura, Naohiro Yoshida, Yuichi Suwa, Kiwamu Minamisawa","doi":"10.1264/jsme2.ME24092","DOIUrl":"10.1264/jsme2.ME24092","url":null,"abstract":"<p><p>Nitrous oxide (N<sub>2</sub>O) is a key atmospheric greenhouse gas that contributes to global warming, with anthropogenic N<sub>2</sub>O emissions from agriculture being a particular concern. Among agricultural sources, unknown soil organisms in the legume rhizosphere emit N<sub>2</sub>O from degraded root nodules. To discriminate between fungal and bacterial N<sub>2</sub>O emissions, we adopted an isotopomer ana-lysis, which provides site preference values (the difference in <sup>15</sup>N abundance of the central and terminal N atoms in the N<sub>2</sub>O molecule). The addition of nitrite instead of nitrate to soybean nodulated roots significantly increased SP<sub>N2O</sub> from -3.5‰ to 4.2‰ in a pot system. Moreover, a mutation of the nirK gene (encoding dissimilatory nitrite reductase) in symbiotic bradyrhizobia significantly increased SP<sub>N2O</sub> from 4.2‰ to 13.9‰ with nitrite. These results suggest that nitrite-utilizing N<sub>2</sub>O emissions via fungal denitrification occurred in the model pot system of the soybean rhizosphere. Microscopic observations showed fungal hyphae and crescent spores around N<sub>2</sub>O-emitting nodules. Therefore, we isolated single spores from soybean nodules under a microscope. A phylogenetic ana-lysis revealed that all 12 fungal isolates were Fusarium species, which exist in soybean field soil. When these isolates were cultivated in glycerol-peptone medium supplemented with nitrate or nitrite (1 mM), 11 of the 12 isolates strongly converted nitrite to N<sub>2</sub>O; however, no N<sub>2</sub>O emissions were noted in the presence of nitrate. A <sup>15</sup>N-nitrite tracer experiment revealed that one N<sub>2</sub>O molecule was derived exclusively from two molecules of nitrite (NO<sub>2</sub><sup>-</sup>) in the fungal culture. These results suggest that nitrite-utilizing Fusarium fungi mediate N<sub>2</sub>O emissions in the soybean rhizosphere.</p>","PeriodicalId":18482,"journal":{"name":"Microbes and Environments","volume":"40 2","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12213065/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144025718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Syntrophic Interaction between an Anoxygenic Photosynthetic Bacterium and a Tetrathionate-reducing Bacterium in Anaerobic Benzoate Degradation.","authors":"Miao He, Shin-Ichi Nishitani, Shin Haruta","doi":"10.1264/jsme2.ME24105","DOIUrl":"10.1264/jsme2.ME24105","url":null,"abstract":"<p><p>The present study exami-ned bacteria that anaerobically degrade the aromatic compound, benzoate, and obtained enrichment cultures from marine sediments under illumination. The enrichment culture contained anoxygenic photosynthetic bacteria and non-photosynthetic bacteria. The photosynthetic strain PS1, a purple sulfur bacterium in the genus Marichromatium, was unable to utilize benzoate; however, when combined with the non-photosynthetic bacterial isolate, Marinobacterium sp. strain BA1, the co-culture grew anaerobically on benzoate in the presence of thiosulfate or tetrathionate. Based on the metabolic profiles of the co-culture and axenic cultures, the following syntrophic interactions were proposed. Strain PS1 oxidizes thiosulfate as the electron source for photosynthesis to produce tetrathionate and relies on carbon dioxide produced through benzoate degradation by strain BA1. Strain BA1 oxidizes benzoate and reduces tetrathionate to provide thiosulfate to strain PS1 for photosynthetic carbon fixation. To the best of our knowledge, this is the first study to report anaerobic benzoate degradation in a photosynthetic co-culture through the syntrophic exchange of sulfur compounds.</p>","PeriodicalId":18482,"journal":{"name":"Microbes and Environments","volume":"40 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11946414/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Gamma Ray-induced Mutations in pyrEF Genes in Frankia casuarinae Strain CcI3.","authors":"Ken-Ichi Kucho, On Han, Miki Yunoki","doi":"10.1264/jsme2.ME24062","DOIUrl":"10.1264/jsme2.ME24062","url":null,"abstract":"<p><p>Frankia spp. are multicellular actinobacteria with the ability to fix atmospheric dinitrogen (N<sub>2</sub>). Frankia fixes N<sub>2</sub> not only in the free-living state, but also in root-nodule symbioses with more than 200 plant species called actinorhizal plants. In the present study, we isolated mutants of the pyrE (orotate phosphoribosyltransferase) and pyrF (orotidine-5'-phosphate decarboxylase) genes in Frankia casuarinae strain CcI3 using gamma rays as a mutagen and systematically identified the types of mutations that occurred in these genes. pyrEF mutants were isolated as uracil auxotrophs using the antimetabolite 5-fluoroorotic acid. We elucidated the nucleotide sequences of the pyrEF genes in 32 uracil auxotrophs, and detected eight substitutions, 17 single-nucleotide deletions, and seven large insertions. Large insertions were insertion sequences (IS elements); four belonged to the IS4 family, two to the IS66 family, and one to the IS110 family. This is the first study to demonstrate the mobilization of IS elements in the Frankia genome.</p>","PeriodicalId":18482,"journal":{"name":"Microbes and Environments","volume":"40 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11946415/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Egodaha G W Gunawardana, Tiffany Joan Sotelo, Kenshiro Oshima, Masahira Hattori, Takashi Mino, Hiroyasu Satoh
{"title":"Categorization of Bacteria That Leak from Activated Sludge to Secondary Treated Water: Year-round Observations.","authors":"Egodaha G W Gunawardana, Tiffany Joan Sotelo, Kenshiro Oshima, Masahira Hattori, Takashi Mino, Hiroyasu Satoh","doi":"10.1264/jsme2.ME24082","DOIUrl":"10.1264/jsme2.ME24082","url":null,"abstract":"<p><p>The present study proposes a categorization of bacteria that leak from activated sludge processes to secondary treated water (STW). Bacterial populations in primary treated water (PTW), activated sludge (AS), STW, and the 0.2 μm-filtrate of STW (FSTW) in a full-scale wastewater treatment plant with two treatment trains were observed for a period of one year using a 16S rRNA ana-lysis approach. The taxonomic groups detected were categorized as different \"leak types\" based on the read occupancies in PTW, AS, STW, and FSTW, where a leak type indicates the likelihood of a taxonomic group to leak to STW. Five leak types were introduced: \"LTE\", \"LTE-I\", \"LTEF\", \"LTF\", and \"NLT\", with \"LT\" for leak type, \"E\" for high read occupancy in STW or the effluent of secondary settling tanks, \"I\" for high read occupancy in PTW or influent to the AS process, \"F\" for high read occupancy in FSTW, and \"NLT\" for a smaller likelihood to leak. Representative taxonomic groups for each leak type were Neisseria and ABY1 for \"LTE\" Parcubacteria for \"LTEF\", Campylobacterota for \"LTE-I\", and Saccharimonadia, Bdellovibrionota, and some lineages in Comamonadaceae for \"LTF\". Although some taxonomic groups, such as Comamonadaceae, included different leak types, the categorization assigned to each taxonomic group was mostly consistent between the two treatment trains. The categorization scheme proposed herein may become a useful key for understanding the characteristics of bacteria that appear in AS and STW.</p>","PeriodicalId":18482,"journal":{"name":"Microbes and Environments","volume":"40 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11946410/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143639708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}