International journal of systematic and evolutionary microbiology最新文献

{"title":"<i>Faecalibacterium langellae</i> sp. nov. isolated from human faeces.","authors":"Adeline Ang Li Xuan, Véronique Robert, Atsushi Hisatomi, Masahiro Hirasaki, Shintaro Maeno, Moriya Ohkuma, Mitsuo Sakamoto, Jean-Marc Chatel, Akihito Endo","doi":"10.1099/ijsem.0.006804","DOIUrl":"https://doi.org/10.1099/ijsem.0.006804","url":null,"abstract":"<p><p>The genus <i>Faecalibacterium</i> is one of the major butyrate-producing bacteria in the human gut. Due to its production of beneficial metabolites and reduced populations in diseased patients, it is regarded as a potential biomarker of healthy gut microbiota. Strains Collection Nationale de Cultures de Microorganismes (CNCM) I-4540 and CNCM I-4541 were isolated from faeces of a healthy elderly and a healthy adult respectively. In this study, we conducted a taxonomic analysis of these strains. Phylogenetic analyses based on 16S rRNA gene and <i>rpoA</i> gene sequences revealed that the two strains belong to the genus <i>Faecalibacterium</i>. A core gene phylogenetic tree further supported their phylogenetic placement. CNCM I-4540 shared an average nucleotide identity (ANI) value of 96.7% and a digital DNA-DNA hybridization (dDDH) value of 74.3% with <i>Faecalibacterium taiwanense</i> HLW78^T, indicating that CNCM I-4540 should be classified as <i>F. taiwanense</i>. In contrast, CNCM I-4541 did not exhibit ANI or dDDH values above the species threshold for any known species within the genus <i>Faecalibacterium</i>. These findings indicate that CNCM I-4541 represents a novel species within the genus <i>Faecalibacterium</i>, for which the name <i>Faecalibacterium langellae</i> sp. nov. is proposed. The type strain is CNCM I-4541^T (=CIP 112513^T=JCM 39552^T).</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144208538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Bradyrhizobium tunisiense</i> sp. nov., a novel rhizobial species isolated from <i>Acacia saligna</i> nodules.","authors":"Jihed Hsouna, Houda Zouagui, Takwa Gritli, Houda Ilahi, Jia-Cheng Han, Muhammad Sulman, Walid Ellouze, Xiao Xia Zhang, Maroua Mansouri, Mustapha Missbah El Idrissi, Soufiane Alami, Pierre Emmanuel Courty, Daniel Wipf, Abdelkader Bekki, James T Tambong, Bacem Mnasri","doi":"10.1099/ijsem.0.006807","DOIUrl":"10.1099/ijsem.0.006807","url":null,"abstract":"<p><p>Three slow-growing rhizobial strains, designated as 1AS2L^T, 1AS20L and 1AS5L, were isolated from nodules of <i>Acacia saligna</i> in Borj Cedria, northern Tunisia. These strains, which belong to the symbiovar cyanophyllae, were characterized using a polyphasic approach. Phylogenetic analysis of the 16S rRNA (<i>rrs</i>) gene placed these strains within the genus <i>Bradyrhizobium</i>, specifically in the superclade associated with <i>Bradyrhizobium japonicum</i>. Further phylogenetic analysis using concatenated sequences of the <i>rec</i>A, <i>atp</i>D, <i>gln</i>II and <i>gyr</i>B genes (totalling 1,734 bp) positioned the strains in a distinct lineage, with <i>Bradyrhizobium shewense</i> identified as their closest related species, sharing a sequence identity of 95.2%. The type strain, 1AS2L^T, exhibited average nucleotide identity values of 89.10%, 89.08% and 89.00% with the type strains of the closest valid species: <i>Bradyrhizobium frederickii</i>, <i>B. shewense</i> and <i>Bradyrhizobium ottawaense</i>, respectively. Additionally, digital DNA-DNA hybridization values confirmed the novelty of strain 1AS2L^T, showing low similarity (38.0%-38.3%) with the type strains of the closest known species. Phylogenomic analyses based on up-to-date bacterial core genes, Type (Strain) Genome Server and the Genome Taxonomy Database (GTDB) pipelines further supported the uniqueness of the 1AS2L^T, 1AS20L and 1AS5L strains. The GTDB analysis also robustly clustered two strains (SZCCT0449 and NSD-1) with our strains, suggesting putative members of the proposed novel species. The differentiation of these novel strains from their closest phylogenetic neighbours was also corroborated by phenotypic, physiological and fatty acid content analyses. Based on genomic, phenotypic and biochemical data, we propose the establishment of a novel species, <i>Bradyrhizobium tunisiense</i> sp. nov., with strain 1AS2L^T (=LMG 33170^T=DSM 114401^T) as the type strain.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12179390/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144325650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Streptomyces sediminimaris</i> sp. nov., a novel actinobacterium with anticancer potential isolated from mangrove sediments.","authors":"Nuttaporn Emthomya, Chusanajit Chuangrattanawan, Chananan Ngamcharungchit, Tepakorn Kongsaya, Pawina Kanchanasin, Wongsakorn Phongsopitanun, Chanwit Suriyachadkun, Sacha J Pidot, Bungonsiri Intra","doi":"10.1099/ijsem.0.006811","DOIUrl":"10.1099/ijsem.0.006811","url":null,"abstract":"<p><p>Two marine actinomycete-like strains, MCC20^T and MCC57, were isolated from Chanthaburi (Thailand) mangrove sediment. Their taxonomic classifications were established through a polyphasic approach. Despite differences in colony morphotypes, genetic and chemotaxonomic analyses confirmed them as the same species within the genus <i>Streptomyces</i>. Both strains contained ll-diaminopimelic acid in their cell wall, with glucose, mannose, ribose and rhamnose identified as whole-cell sugars. Their phospholipid profile comprises phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. The predominant fatty acids were iso-C_15:0, anteiso-C_15:0, iso-C_16:0 and anteiso-C_17:0 with MK-9(H₈) as the primary menaquinone, while MK-9(H₆) and MK-9(H₄) were unique to strain MCC57. Both strains exhibited anticancer activity against colorectal (HCT116) and lung (A549) cancer cells, with strain MCC20^T being more potent. Their 16S rRNA gene sequences showed 100% similarity, with 99.2% similarity to <i>Streptomyces fumigatiscleroticus</i> NBRC 12999^T. Nevertheless, a phylogenomic tree placed them closer to <i>Streptomyces spinosirectus</i> CRSS-Y-16^T, <i>Streptomyces plumbidurans</i> KC 17012^T and <i>Streptomyces spinosisporus</i> 7R016^T. Nearly 100% average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values highlighted the identity of strains MCC20^T and MCC57, while ANI (89.4%) and dDDH (35.5%) values were well below the respective 95 and 70% thresholds for related species. This supported their novelty. Based on their genotypes and phenotypes, strains MCC20^T (=NBRC 117131^T=TBRC 19240^T) and MCC57 (=NBRC 117132=TBRC 19241) are identified as phenotypic variants of a new species, <i>Streptomyces sediminimaris</i> sp. nov., with strain MCC20^T designated as the type strain (~9.2 Mb genome, 72.0 mol% G+C content).</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12166134/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144284346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Flavobacterium mekongense</i> sp. nov., isolated from the Mekong River in Thailand.","authors":"Chitwadee Phithakrotchanakoon, Supattra Kitikhun, Paopit Siriarchawatana, Piyanat Charoenyingcharoen, Sukanya Jeennor, Thanyakorn Nilsakha, Amonwan Chanpet, Thanat Vorajinda, Sermsiri Mayteeworakoon, Pattaraporn Yukphan, Supawadee Ingsriswang","doi":"10.1099/ijsem.0.006815","DOIUrl":"https://doi.org/10.1099/ijsem.0.006815","url":null,"abstract":"<p><p>Two Gram-stain-negative, aerobic, non-motile, non-gliding, rod-shaped bacterial strains, designated as TBRC 19031^T and TBRC 19032, were isolated from water samples collected from the Mekong River, Thailand. Strain TBRC 19031^T was obtained from Chiang Saen in the upstream section near the borders with China and Myanmar, while TBRC 19032 originated from Khong Chiam, in the downstream section where the river exits Thailand. Colonies of both strains were circular, smooth and deep yellow on Reasoner's 2A agar and did not produce flexirubin-type pigments. Phylogenetic analysis with 16S rRNA gene sequences placed both strains within the genus <i>Flavobacterium</i>, showing the highest sequence similarity to <i>Flavobacterium cheonhonense</i> ARSA-15^T (98.29% for TBRC 19031^T and 98.22% for TBRC 19032). However, whole-genome comparisons between the strains and <i>F. cheonhonense</i> ARSA-15^T revealed average nt identity (89.39% and 89.29%), average aa identity (92.84% and 92.95%) and digital DNA-DNA hybridization (35.00% and 34.70%). The predominant fatty acids were iso-C_15:1, iso-C_15:0 and iso-C_15:0 3-OH, and menaquinone MK-6 was the major respiratory quinone. The major polar lipids of both strains included phosphatidylethanolamine, steryl ester and diacylglycerol. The genome sizes were 3.02 and 3.04 Mbp, with G+C contents of 38.3% and 38.2% for TBRC 19031^T and TBRC 19032, respectively. Comparative genomic analyses revealed the absence of genes involved in sulphate reduction and denitrification pathways and the presence of a gene encoding phosphatidylinositol synthase, distinguishing them from other <i>Flavobacterium</i> within the clade. Ecological profiling using public metagenomic datasets showed that both strains were associated with lotic freshwater environments. This study not only introduces <i>Flavobacterium mekongense</i> sp. nov. as a new species but also provides broader insights into the ecology, metabolism and environmental distribution of freshwater <i>Flavobacterium</i>. The genomic features identified here offer promising leads for future studies in microbial ecology, comparative genomics and functional gene mining in aquatic ecosystems. The type strain is TBRC 19031^T (TBRC 19031^T=NBRC 117006^T).</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144325651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Lacticaseibacillus salsurae</i> sp. nov. and <i>Levilactobacillus muriae</i> sp. nov., isolated from traditional Chinese pickle.","authors":"Si-Tong Song, Ting-Yu Wang, Xin-Yu Zhu, Chun Tao Gu","doi":"10.1099/ijsem.0.006816","DOIUrl":"https://doi.org/10.1099/ijsem.0.006816","url":null,"abstract":"<p><p>Two novel bacteria (designated N501-2^T and N40-8-2^T) belonging to the genera <i>Lacticaseibacillus</i> and <i>Levilactobacillus</i> were isolated from traditional Chinese pickle ('Suan cai') and identified. Strain N501-2^T was phylogenetically related to the type strains of <i>Lacticaseibacillus baoqingensis</i>, <i>Lacticaseibacillus porcinae</i>, <i>Lacticaseibacillus manihotivorans</i> and <i>Lacticaseibacillus jixiensis</i>, having 98.7-99.4% 16S rRNA gene sequence similarities. Strain N40-8-2^T was phylogenetically related to the type strains of <i>Levilactobacillus fuyuanensis</i>, <i>Levilactobacillus parabrevis</i>, <i>Levilactobacillus tujiorum</i>, <i>Levilactobacillus hammesii</i>, <i>Levilactobacillus senmaizukei</i> and <i>Levilactobacillus tangyuanensis</i>, having 98.4-99.4% 16S rRNA gene sequence similarities. Strain N501-2^T had 74.0-84.2% ANI (average nucleotide identity), 20.8-28.4% dDDH (digital DNA-DNA hybridization) and 73.5-86.8% AAI (average amino acid identity) values with <i>L. manihotivorans</i> DSM 13343^T, <i>L. porcinae</i> JCM 19617^T, <i>L. jixiensis</i> N163-3-2^T and <i>L. baoqingensis</i> 47-3^T. Analyses based on whole-genome sequences indicated that strain N40-8-2^T was most closely related to the type strains of <i>L. fuyuanensis</i>, <i>L. parabrevis</i>, <i>L. tujiorum</i> and <i>L. hammesii</i>, having less than 87.4% ANI, 33.6% dDDH and 93.2% AAI values. Based upon the data obtained in the present study, two novel species, <i>Lacticaseibacillus salsurae</i> sp. nov. and <i>Levilactobacillus muriae</i> sp. nov., are proposed, and the type strains are N501-2^T (=CCTCC AB 2024124^T=JCM 37150^T=LMG 33663^T) and N40-8-2^T (=CCTCC AB 2024128^T=JCM 37001^T=LMG 33659^T), respectively.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144325652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Methylobacterium oryzisoli</i> sp. nov., a novel methylotrophic methanol-utilizing bacterium isolated from the paddy soil.","authors":"Lu Liu, Shu-Yi Zhang, Peng Gao, Hao-Cheng Shen, Christopher Rensing, Guo-Hong Liu, Shun-Gui Zhou","doi":"10.1099/ijsem.0.006805","DOIUrl":"https://doi.org/10.1099/ijsem.0.006805","url":null,"abstract":"<p><p>Four pink-pigmented bacteria, designated as strains sgz302003^T, sgz302004, sgz302005 and sgz302006, were isolated from a paddy soil enrichment. The cells were aerobic, Gram-stain-negative, motile and short rods. The ranges and optima of the temperature, NaCl concentration and pH for growth were 25-37 °C (optimum, 30 °C), 0-2% (w/v) (optimum, 0-0.5%) and pH 5.0-10.0 (optimum, pH 6.5), respectively. Major fatty acids were summed feature 8 (C_18:1 <i>ω</i>7<i>c</i> and/or C_18:1 <i>ω</i>6<i>c</i>). Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that the four strains were affiliated with the genus <i>Methylobacterium</i> and were most closely related to <i>Methylobacterium isbiliense</i> AR24^T (99.2% sequence similarity), <i>Methylobacterium nodulans</i> ORS 206^T (97.7%) and <i>Methylobacterium currus</i> PR1016A^T (97.4%). The methanol dehydrogenase <i>mxaF</i> gene was absent, but <i>xoxF</i> was present. Phylogenomic tree supported that these four strains formed a distinct clade within <i>Methylobacterium</i>. Q-10 was detected as the only respiratory quinone in the studied strains. The genomic DNA G+C content was 70.7-70.8 %. The orthologous average nucleotide identity and <i>in silico</i> digital DNA-DNA hybridization values between the four strains and <i>M. isbiliense</i> AR24^T were 91.8-91.9% and 53.0-53.3%, respectively, while those with <i>M. nodulans</i> ORS 206^T were 86.3-86.5% and 25.5%. Phylogenomic, physiological and chemotaxonomic analyses indicate that the four strains represent a novel species within the genus <i>Methylobacterium</i>, for which the name <i>Methylobacterium oryzisoli</i> sp. nov. is proposed, with strain sgz302003^T (= MCCC 1K09384^T=KCTC 8693^T) as the type strain.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144234051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Taxonomic rearrangement of <i>Salinibacterium</i>, <i>Leifsonia</i>, <i>Diaminobutyricibacter</i>, <i>Antiquaquibacter</i>, <i>Homoserinimonas</i> and <i>Glaciibacter</i>: refining genus boundaries and proposal of two new genera - <i>Orlajensenia</i> gen. nov. and <i>Leifsonella</i> gen. nov.","authors":"Maher Gtari, Dhouha Boussoufa, Faten Ghodhbane-Gtari, Imed Sbissi","doi":"10.1099/ijsem.0.006809","DOIUrl":"https://doi.org/10.1099/ijsem.0.006809","url":null,"abstract":"<p><p>The actinobacterial family <i>Microbacteriaceae</i> comprises a diverse group of Gram-positive bacteria with high G+C content and complex taxonomic challenges. Traditional polyphasic approaches, based on 16S rRNA phylogeny and phenotypic traits, have in some instances resulted in polyphyletic taxonomic groupings, necessitating genome-wide methodologies to better resolve evolutionary relationships. This study employs a taxogenomic approach - incorporating 16S rRNA gene sequencing, core protein phylogeny, average amino acid identity and percentage of conserved proteins - to reassess the genera <i>Leifsonia</i>, <i>Salinibacterium</i>, <i>Homoserinimonas</i>, <i>Glaciibacter</i>, <i>Antiquaquibacter</i> and <i>Diaminobutyricibacter</i>. The findings reveal significant polyphyly in <i>Leifsonia</i>, <i>Glaciibacter</i> and <i>Salinibacterium</i>, indicating ecological convergence rather than shared ancestry. Proposed taxonomic revisions include the reclassification of <i>Salinibacterium soli</i> and <i>Salinibacterium metalliresistens</i> into <i>Antiquaquibacter</i>, <i>Salinibacterium hongtaonis</i> and <i>Salinibacterium sedimenticola</i> into <i>Homoserinimonas</i>, and <i>Leifsonia psychrotolerans</i> and <i>Leifsonia kafniensis</i> into <i>Glaciibacter</i>. <i>Diaminobutyricibacter tongyongensis</i> should be incorporated into <i>Leifsonia</i>. Additionally, <i>Leifsonia rubra</i> is reassigned to <i>Salinibacterium</i>. Two new genera were also proposed to encompass \"Leifsonia flava\" and <i>Glaciibacter flavus</i>, named <i>Orlajensenia</i> gen. nov. and another to encompass <i>Leifsonia bigeumensis</i>, named <i>Leifsonella</i> gen. nov. These genome-based insights provide a refined framework for the taxonomy of <i>Microbacteriaceae</i>, enhancing our understanding of their evolutionary and ecological roles.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144325706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Roseovarius roseus</i> sp. nov. and <i>Roseovarius maritimus</i> sp. nov., isolated from marine coastal sediment.","authors":"Xu-Nian Yang, Zi-Yang Zhou, Jing Zhang, Zhenxing Xu, Zong-Jun Du","doi":"10.1099/ijsem.0.006782","DOIUrl":"https://doi.org/10.1099/ijsem.0.006782","url":null,"abstract":"<p><p>Two novel Gram-stain-negative, rod-shaped, facultatively anaerobic and non-motile bacterial strains, designated as S1116L3^T and S4756^T, were isolated from the marine sediment of Jingzi Port, Weihai, China. Strain S1116L3^T grew at temperatures 15-37 ℃ within pH 5.5-9.0 and in the presence of 1.0%-10.0% (w/v) NaCl. Optimal growth required 3.0% (w/v) NaCl at 30 ℃ and pH 7.0. Strain S4756^T grew at 15-37 ℃, pH 6.0-9.0 and in the presence of 1.0%-10.0% (w/v) NaCl. Optimal growth appeared with 2.0% (w/v) NaCl at 30 ℃ and pH 7.0. Strains S1116L3^T and S4756^T had a major fatty acid of C_18 : 1 <i>ω</i>7<i>ϲ</i>. The predominant respiratory quinone of the two strains was Q10. The major polar lipids detected in the two strains were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The phylogenetic analysis based on 16S rRNA gene sequences placed the strains S1116L3^T and S4756^T into the genus <i>Roseovarius</i>. The comparison of 16S rRNA gene sequence similarities revealed that strains S1116L3^T and S4756^T had the closest relative with <i>Roseovarius aquimarinus</i> KCTC 32014^T (98.4% and 97.9%, respectively). These values were below the species delineation threshold of 98.6%. The average nucleotide identity (ANI) values based on the genome similarity between strain S1116L3^T and species of the genus <i>Roseovarius</i> ranged from 74.6% to 82.8%, while the ANI values ranged from 74.3% to 82.5% for strain S4756^T, which is significantly lower than the species delineation threshold of 95%. The DNA G+C content of both strains is 63.0%. Based upon the results presented in this study, strains S1116L3^T and S4756^T represent two novel species of the genus <i>Roseovarius</i>, for which the names <i>Roseovarius roseus</i> sp. nov. and <i>Roseovarius maritimus</i> sp. nov. are proposed with the type strains S1116L3^T (=KCTC 8178^T=MCCC 1H01426^T=SDUM 031094^T) and S4756^T (=KCTC 8179^T=MCCC 1H01425^T=SDUM 031096^T), respectively.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144208539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Gaoshiqia hydrogeniformans</i> sp. nov., a novel hydrogen-producing bacterium isolated from a deep diatomaceous shale formation.","authors":"Akio Ueno, Kiyoshi Sato, Shuji Tamamura, Takuma Murakami, Hidenori Inomata, Satoshi Tamazawa, Yuki Amano, Kazuya Miyakawa, Takeshi Naganuma, Toshifumi Igarashi","doi":"10.1099/ijsem.0.006802","DOIUrl":"https://doi.org/10.1099/ijsem.0.006802","url":null,"abstract":"<p><p>In the deep subsurface Miocene groundwater of Horonobe, Hokkaido, Japan, we isolated strain Z1-71ᵀ, an obligately anaerobic, Gram-stain-negative, non-motile bacterium with rod-shaped morphology (2.7-4.8 µm × 0.4 µm). This strain could grow at 10-42 °C (optimum, 30-35 °C), over a pH range of 6.0-9.0 (optimum, pH 7.0-7.2) and in the presence of 0-30 g l^-1 NaCl (optimum, 5-15 g l^-1). Physiologically, strain Z1-71ᵀ displayed positive catalase activity but negative oxidase reaction, with notable hydrogen production during d-glucose metabolism. Chemotaxonomic analysis revealed MK-7 as the sole respiratory quinone, while cellular lipid profiling identified four unidentified polar lipids, one unidentified phospholipid, one unidentified aminolipid and one unidentified glycolipid. The predominant fatty acids comprised C_17:0 (23.4%), C_17:1 <i> ω6</i>c (13.8%), anteiso-C_15 :0 (6.9%) and iso-C_17:0 3-OH (6.6%). Genomic characterization determined a genome size of 5.7 Mb with a G+C content of 45.9 mol%. Comprehensive phylogenetic analysis of 16S rRNA gene sequences positioned strain Z1-71ᵀ within the family <i>Prolixibacteraceae</i>, showing the highest sequence similarity to <i>Gaoshiqia sediminis</i> A06^T (95.0%), followed by <i>Mangrovibacterium diazotrophicum</i> SCSIO N0430^T (94.6%), <i>Mangrovibacterium lignilyticum</i> BM_7^T (94.3%) and <i>Mangrovibacterium marinum</i> FA423^T (93.6%). Digital DNA-DNA hybridization and orthologous average nucleotide identity tool using USEARCH (OrthoANIu) analyses between strain Z1-71ᵀ and <i>G. sediminis</i> A06^T yielded values of 20.7% and 75.8%, respectively, confirming genomic distinction. Based on these phylogenetic and phenotypic characteristics, we propose strain Z1-71ᵀ (=DSM 117644ᵀ=JCM 36072ᵀ) as the type strain of a novel species, <i>Gaoshiqia hydrogeniformans</i> sp. nov. This discovery not only expands our understanding of microbial diversity in deep terrestrial subsurface environments but also highlights the ecological significance of hydrogen-producing anaerobes in these previously underexplored habitats.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144225440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphological and phylogenetic analyses reveal <i>Conidiobolus longivillosus</i> sp. nov., a new cryptic species with long villose conidia in the <i>Conidiobolus coronatus</i> species complex.","authors":"Jie Wang, Yong Nie, Heng Zhao, Ying Chang, XiaoYong Liu, Bo Huang","doi":"10.1099/ijsem.0.006808","DOIUrl":"10.1099/ijsem.0.006808","url":null,"abstract":"<p><p><i>Conidiobolus coronatus</i> (Cost.) Batko is the most common species within the genus <i>Conidiobolus sensu stricto</i> (s.s.). Historically, the presence of villose conidia in <i>C. coronatus</i> was considered a unique morphological characteristic distinguishing it from other <i>Conidiobolus</i> s.s. members. However, <i>Conidiobolus lunulus</i>, reported to infect leafcutter ants and produce half-moon-shaped microspores, was identified as the second species with villose conidia. These findings suggest that <i>C. coronatus</i> represents a species complex. In the present study, we isolated the third species with villose conidia, characterized by its long villi and named it <i>Conidiobolus longivillosus</i> sp. nov. Phylogenetic analyses based on single-gene phylogenies (nucLSU, nucSSU and ITS) and multi-gene phylogenies (nucLSU, nucSSU, <i>TEF1</i>, ITS and mtSSU), along with the pairwise homoplasy index test and Poisson tree processes analysis, were performed to recognize this cryptic species. The results not only support <i>C. longivillosus</i> as an independent species but also imply the existence of cryptic species within the <i>C. coronatus</i> species complex.</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144284347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}