Systematic and applied microbiology最新文献

{"title":"Genomic characterization of Gillisia xinjiangensis sp. nov.: insights into nitrogen metabolism, stress adaptation, and application potential","authors":"Hao-hao Wang ,&nbsp;Chi Zhang ,&nbsp;Ya-qin Chen ,&nbsp;Yi-fan Guo ,&nbsp;Li-jian Ding ,&nbsp;Sheng-fa Zhang ,&nbsp;Gai-jun Du ,&nbsp;Wei-yan Zhang ,&nbsp;Shan He","doi":"10.1016/j.syapm.2025.126645","DOIUrl":"10.1016/j.syapm.2025.126645","url":null,"abstract":"<div><div>High-altitude saline lakes host distinctive microbial communities characterized by specialized adaptations to extreme environmental conditions. However, the underlying mechanisms enabling bacterial survival and physiological function in these habitats remain largely unexplored. In this study, a novel Gram-stain-negative, non-motile, rod-shaped bacterium, designated strain Q332^T, was isolated from sediment samples collected from Achikkul Lake, a high-altitude saline lake in Xinjiang, northwestern China. The strain was facultatively aerobic, and grew optimally at 28 °C, pH 7.0, and 3.0 % (<em>w</em>/<em>v</em>) NaCl. Catalase and oxidase activities were positive. Major fatty acids identified in strain Q332^T included anteiso‐C_15:0, anteiso-C_17:1, iso‐C_15:0 and C_16:0. The primary respiratory quinone detected was menaquinone-6 (MK-6). Polar lipid analyses identified phosphatidylethanolamine (PE), one unidentified acyloxyacyl phosphatidylglycerol (APGL), three unidentified lipids (L), three glycolipids (GL), one phospholipid (PL), and four amidolipids (AL). The genomic DNA G + C content is 38.9 %. Genomic characterization revealed a versatile metabolic repertoire, including unique C1-unit metabolic pathways and comprehensive nitrogen cycling capabilities, notably denitrification and assimilatory nitrate reduction. Furthermore, strain Q332^T displayed robust mechanisms for stress adaptation, encompassing tolerance to cold and osmotic stress, defenses against oxidative stress, and resistance to heavy metals. Based on phenotypic, chemotaxonomic, phylogenetic, and genomic features, strain Q332^T is considered to represent a novel species of the genus <em>Gillisia</em>, for which the name <em>Gillisia xinjiangensis</em> sp. nov. is proposed. The type strain is Q332^T (=KCTC 102200^T = MCCC 1K09490^T).</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 5","pages":"Article 126645"},"PeriodicalIF":4.2,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144864606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A practical guide on environmental genomics for prokaryotic systematics","authors":"Nathan M. Ernster ,&nbsp;Luis M. Rodriguez-R","doi":"10.1016/j.syapm.2025.126643","DOIUrl":"10.1016/j.syapm.2025.126643","url":null,"abstract":"<div><div>Environmental shotgun sequencing can provide great insight into microbial community profiles, functional capabilities, and the recovery of metagenome-assembled genomes (MAGs) which represent individual microbiome members. Similarly, assembly of single-cell amplified genomes (SAGs) is possible through advances in microfluidics and sequencing techniques. These fields have experienced tremendous growth in the amount of data produced, the ongoing development of analytical tools, and ultimately, the number of genomes recovered lacking valid names. As most microbes are uncultivable and therefore incompatible with traditional naming requirements, sequence databases are filled with genomes of varying quality and without standardized nomenclature, hindering communication and data usability. Overcoming these limitations, the recently introduced C<em>ode of Nomenclature of Prokaryotes Described from Sequence Data</em> (SeqCode) includes genome quality criteria and nomenclature standards to validly name uncultivated prokaryotes based on DNA sequence. Metagenomics and systematics can be overwhelming fields for new users, so here we provide a guide to help clarify topics and point out special considerations. These topics include metagenomic pipelines, genome quality assessment criteria, followed by taxonomy and trait prediction tools. Next, we cover source metadata, methods for abundance and occupancy measurement, and lastly, nomenclature and name registration. Community efforts to generate high-quality prokaryotic genomes with thorough descriptions and valid names are crucial for the future usability and communication of environmental genomic data.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 5","pages":"Article 126643"},"PeriodicalIF":4.2,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrogen fixation in Pampinifervens, a new species-rich genus of Aquificaceae that inhabits a wide pH range in terrestrial hot springs","authors":"Marike Palmer ,&nbsp;Nancy O. Nou ,&nbsp;Lara A. Turello ,&nbsp;Carolyn E. Power ,&nbsp;John C. Ong ,&nbsp;Jonathan K. Covington ,&nbsp;Dengxun Lai ,&nbsp;Xavier Mayali ,&nbsp;Anna-Louise Reysenbach ,&nbsp;Yan-Ling Qi ,&nbsp;Jeremy A. Dodsworth ,&nbsp;Jian-Yu Jiao ,&nbsp;Lan Liu ,&nbsp;Zheng-Han Lian ,&nbsp;Meng-Meng Li ,&nbsp;Yitai Liu ,&nbsp;Ranjani Murali ,&nbsp;Brandon R. Briggs ,&nbsp;Hongyan Zuo ,&nbsp;Stephen R. Quake ,&nbsp;Brian P. Hedlund","doi":"10.1016/j.syapm.2025.126644","DOIUrl":"10.1016/j.syapm.2025.126644","url":null,"abstract":"<div><div>Members of the <em>Aquificota</em> play important roles in hydrogen, sulfur, and carbon cycles in geothermal systems as ubiquitous and abundant chemolithoautotrophs; however, their roles in the nitrogen cycle are poorly defined. Here, we show that <em>Aquificaceae</em> isolate T-2^T from Tengchong, China, fixes nitrogen based on growth with dinitrogen as the sole nitrogen source and incorporation of ¹⁵N atoms when grown with ¹⁵N₂. We further show evidence that suggests its nitrogen fixation (<em>nif</em>) genes are transcribed in situ in a nearby spring. We propose the name <em>Pampinifervens diazotrophicum</em> gen. et sp. nov., with strain T-2^T (= JCM 35475^T = DSM 116324^T) as the nomenclatural type. Its close relative designated <em>Pampinifervens florentissimum</em> sp. nov. T-8^T (= CGMC 1.5214^T = JCM 33569^T) does not fix nitrogen but respires nitrate. Analysis of 104 metagenome-assembled genomes from 84 metagenomes allowed us to circumscribe the genus <em>Pampinifervens</em> and identify at least 16 sympatric <em>Pampinifervens</em> species that dominate the <em>Aquificaceae</em> populations in diverse hot springs in southwest China, with distinct species globally. Analysis of these <em>Pampinifervens</em> genomes revealed variable presence of <em>nif</em> and denitrification genes and frequent gene loss and horizontal transfer. Genes for pH homeostasis were also present in <em>Pampinifervens</em> genomes, with a proliferation in species from Tengchong, consistent with the wide pH growth range of both <em>Pampinifervens</em> isolates and the prevalence of <em>Pampinifervens</em> in both alkaline and acidic springs. The dynamic evolution of <em>nif</em> and denitrification genes, along with pH homeostasis genes, may facilitate the diversification of <em>Pampinifervens</em> into diverse springs with different nitrogen availability.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 5","pages":"Article 126644"},"PeriodicalIF":4.2,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of cluster analysis of elastic light scatter profiles for the identification of foodborne Bacteria","authors":"Sana Bari ,&nbsp;Yuwei Zhang ,&nbsp;Valery Patsekin ,&nbsp;J. Paul Robinson ,&nbsp;Bartek Rajwa ,&nbsp;Andrew Gehring ,&nbsp;James Lindsay ,&nbsp;Don Kulasiri ,&nbsp;Stephen L.W. On","doi":"10.1016/j.syapm.2025.126641","DOIUrl":"10.1016/j.syapm.2025.126641","url":null,"abstract":"<div><div>Elastic Light Scatter (ELS) profiling is a novel approach for simultaneous detection and identification of bacteria cultured on solid agar media. The profiles comprise a range of different scatter features that can be used jointly or individually as a basis for comparison. We examined the utility of cluster analysis of ELS profiles for classification and identification of bacteria of relevance to foods. A total of 1562 colonies from 48 strains, representing 17 different species distributed among four genera, were examined. Each of three scatter-derived features (Zernike moments, pseudo-Zernike moments, proprietary Patsekin elements) were used individually and in combination for the cluster analysis. Of these, a combination of Patsekin elements and pseudo-Zernike moments yielded clusters that best reflected the known taxonomic relationships among the strains examined. Evidence of Genus-level markers of colony architecture was seen and there was a general agreement of clustering at the species level. Nonetheless, some individual colonies did not cluster with the majority of others from the same taxon, which could reflect an aberrant ELS phenotype, or known challenges in depicting strain relationships using cluster analytical methods. However, when compared with UMAP data processing, relationships between individual colonies were more easily discerned by inspecting the dendrogram. Cluster analysis of ELS profiles is a useful adjunctive tool for the classification and identification of bacteria and results may also be helpful in informing the development and improvement of other data analytical tools for ELS profile analysis.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 5","pages":"Article 126641"},"PeriodicalIF":3.3,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Astrobacterium formosum gen. nov., sp. nov., a novel psychrotolerant rosette-forming bacterium from a laboratory psychrophilic EGSB bioreactor","authors":"V.V. Potokina ,&nbsp;S.N. Parshina ,&nbsp;A.Y. Merkel ,&nbsp;A.G. Elcheninov ,&nbsp;A.V. Vishnyakova ,&nbsp;A.N. Avtukh ,&nbsp;N.A. Kostrikina ,&nbsp;V.M. Tereshina ,&nbsp;Y.V. Litti","doi":"10.1016/j.syapm.2025.126640","DOIUrl":"10.1016/j.syapm.2025.126640","url":null,"abstract":"<div><div>A new psychrotolerant, facultative anaerobic bacterium, strain Astr-EGSB^T, was isolated from a syntrophic propionate-oxidizing consortium obtained from a low-temperature expanded granular sludge bed (EGSB) bioreactor fed with a mixture of volatile fatty acids. The cells of this strain were Gram-negative and non-spore-forming rods (0.5<strong>·</strong>0.8–1.5<strong>·</strong>9 μm), grew either as individual cells or formed rosettes of various sizes, resembling stars. Bacteria reproduced by budding, and each cell has a sticky, non-reproductive pole that allows them to attach to other cells, forming rosette-like clusters. This strain could grow between 5 and 40 °C, with pH ranging from 4.5 to 7.5 and NaCl concentration of 0 to 2 %. It could degrade a variety of carbon substrates, including sugars, alcohols, casamine acids and several organic acids, but could not grow under photoautotrophic conditions. During glucose fermentation, the products include lactate, acetate, isobutyrate, CO₂, and traces of succinate. Major cellular fatty acids were C_18:1ω9c and C_19:0 cyclo <em>ω</em>9c, menaquinone МХ-10(H10). Main polar lipids were phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol. Sequence comparison of the 16S rRNA gene revealed that strain Astr-EGSB^T was related to <em>Pseudorhodoplanes sinuspersici</em> RIPI 110^T with a similarity of 95.0 %. Based on phylogenomic analysis using 120 marker genes, strain Astr-EGSB^T belongs to the distinct genus-level phylogenetic lineage that is most related to the genus <em>Rhodoplanes</em>. The G + C content of genomic DNA was 65.8 mol%. Based on genomic and physiological characteristics of strain Astr-EGSB^T, a new genus and a new species, <em>Astrobacterium formosum</em> gen. Nov., sp. nov., is proposed, with Astr-EGSB^T as the type strain.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 5","pages":"Article 126640"},"PeriodicalIF":3.3,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pyranulibacter aquaticus gen. nov., sp. nov., the first nitrate-reducing representative of the class Ignavibacteria from an Iturup well","authors":"Olga A. Podosokorskaya ,&nbsp;Alexander Y. Merkel ,&nbsp;Andrei A. Novikov ,&nbsp;Alexandra A. Klyukina ,&nbsp;Alexander G. Elcheninov","doi":"10.1016/j.syapm.2025.126639","DOIUrl":"10.1016/j.syapm.2025.126639","url":null,"abstract":"<div><div>A novel facultatively anaerobic moderately thermophilic bacterium, strain 4301-Me^T was isolated from the well 13k on the Iturup Island (Kuril Islands, Russian Federation). Gram-stain-negative, motile rods were present singly, in pairs, rosettes, and aggregates, or formed biofilms. The strain grew optimally at 50–55 °C, pH 6.7–7.0 and 0.2–0.4 % NaCl. It did not require yeast extract for growth and utilized mono-, di- and polysaccharides (cellulose, starch, xanthan gum, locust bean gum, glucomannan, lichenan, amorphous chitin) as well as proteinaceous substrates (gelatin, peptone, beef and yeast extract). Growth under anaerobic conditions was observed in the presence and absence of external electron acceptors. Sulfur, thiosulfate, nitrate, arsenate, Fe-citrate, and ferrihydrite were reduced with acetate, or yeast extract as electron donors. The respiratory quinone was MK-7. Major cellular fatty acids were iso-C_15:0, iso-C_16:0, anteiso-C_15:0, 3OH-C_14:0, 3OH-C_13:0. The size of the genome and genomic DNA G + C content of strain 4301-Me^T were 3.34 Mb and 33 %, respectively. According to the 16S rRNA gene sequence and conserved protein sequences phylogenies, strain 4301-Me^T represented a distinct lineage of the family <em>Melioribacteraceae</em> within the class <em>Ignavibacteria</em>. Based on phylogenomic analysis and phenotypic features, the novel isolate was assigned to a novel genus, for which the name <em>Pyranulibacter</em> gen. nov. is proposed. Strain 4301-Me^T represents its type species <em>Pyranulibacter aquaticus</em> sp. nov. (=CGMCC 1.18061^T = B-3822^T = BIM B-2047^T = UQM 41592^T).</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 5","pages":"Article 126639"},"PeriodicalIF":3.3,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144623499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genomic and phylogenetic re-assessment of the genus Stenotrophomonas: Description of Stenotrophomonas thermophila sp. nov., and the proposal of Parastenotrophomonas gen. Nov., Pseudostenotrophomonas gen. Nov., Pedostenotrophomonas gen. Nov., and Allostenotrophomonas gen. Nov.","authors":"Amandine Chauviat,&nbsp;Danis Abrouk,&nbsp;Elisabeth Brothier,&nbsp;Daniel Muller,&nbsp;Thibault Meyer ,&nbsp;Sabine Favre-Bonté","doi":"10.1016/j.syapm.2025.126630","DOIUrl":"10.1016/j.syapm.2025.126630","url":null,"abstract":"<div><div>The <em>Stenotrophomonas maltophilia</em> species complex (Smc) currently comprises 19 genomospecies, known for their ecological versatility and role as opportunistic human pathogens. However, significant genomic variability among strains has complicated their classification, and only a few species within the Smc have been validly described. Despite successive taxonomic revisions, there remains no consensus on the naming of many genomospecies, largely due to the phenotypic heterogeneity across the complex.</div><div>In this study, we performed a comprehensive genomic and phylogenetic re-assessment to clarify the boundaries of the <em>Stenotrophomonas</em> genus and its species complex. Using whole-genome phylogeny and Overall Genome-Related Indices (OGRIs) such as digital DNA-DNA hybridization (dDDH), Average Nucleotide Identity (ANIb and ANIm), and Average Amino Acid Identity (AAI), we established precise cutoffs for defining the genus and the Smc. Our analysis led to the formal revision of the <em>Stenotrophomonas</em> genus, resulting in the delineation of four novel bacterial genera: <em>Allostenotrophomonas</em> gen. Nov., <em>Pedostenotrophomonas</em> gen. Nov., <em>Parastenotrophomonas</em> gen. Nov., and <em>Pseudostenotrophomonas</em> gen. Nov. Additionally, we standardized the nomenclature within the Smc by identifying reference strains for each genomospecies. Among these, we describe a novel species, <em>Stenotrophomonas thermophila</em> sp. nov. (type strain BurA1^T = LMG 33562^T = EML 1882^T). This study provides a robust framework for future taxonomic and ecological studies within the <em>Stenotrophomonas</em> genus.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 4","pages":"Article 126630"},"PeriodicalIF":3.3,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144338327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polyphasic taxonomic description of Streptomyces tritrimontium sp. nov., actinomycetes isolated from moonmilk in Szczelina Chochołowska cave of Tatra Mountains in Poland and emended descriptions of Streptomyces manipurensis Nimaichand et al. 2021 and Streptomyces nojiriensis Ishida et al. 1967","authors":"Patrycja Bielańska ,&nbsp;Patrycja Golińska ,&nbsp;Elaine Romines ,&nbsp;Łukasz Rąbalski ,&nbsp;Grzegorz Węgrzyn","doi":"10.1016/j.syapm.2025.126627","DOIUrl":"10.1016/j.syapm.2025.126627","url":null,"abstract":"<div><div>In the present study the taxonomic position of two streptomycete strains, isolated from moonmilk in Szczelina Chochołowska cave located in Tatra Mountains in Poland, was established using a polyphasic taxonomic approach. Strains 2.9^T and 4.24 have morphological characteristics and chemotaxonomic properties consistent with their classification in the genus <em>Streptomyces</em>. They are Gram-stain-positive filamentous bacteria which formed an extensively branched substrate mycelium and straight long chains of smooth surfaced spores. They contain <em>LL</em>-diaminopimelic acid, glucose and ribose in whole-organism hydrolysates, produce major proportions of straight, iso- and <em>anteiso</em>- fatty acids, hexa- and octa‑hydrogenated menaquinones with nine isoprene units and have a polar lipid pattern with phosphatidylethanolamine (diagnostic lipid). Strains 2.9^T and 4.24 formed a distinct clade within the <em>Streptomyces</em> 16S rRNA gene tree sharing 100 % sequence similarity with <em>Streptomyces stoeckheimensis</em> DSM 116496ᵀ. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values calculated from the whole genome sequences of strains 2.9^T and 4.24 and their closely related phylogenomic neighbour were found to be 90.4 and 36.3 %, respectively, indicating that they belong to different genomic species. Consequently, based on the genomic, phylogenetic and associated phenotypic data it is proposed that strains 2.9^T and 4.24 be assigned to the genus <em>Streptomyces</em> as <em>Streptomyces tritrimontium</em> sp. nov. with strain 2.9^T (DSM 119353^T = PCM 3548^T) as the type strain.</div><div>The genomes of strains 2.9^T and 4.24 contain relatively high number of biosynthetic gene clusters (28 and 27, respectively), some of which were discontinuously distributed, indicating ones predicted to express for novel specialized metabolites.</div><div>Data acquired in the present study have also been used to emend the descriptions of <em>Streptomyces manipurensis</em> and <em>Streptomyces nojiriensis</em>.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 4","pages":"Article 126627"},"PeriodicalIF":3.3,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revisiting carbon monoxide metabolism in the Moorella genus and isolation of a novel Moorella species","authors":"Anastasia Galani ,&nbsp;Melissa Antony Venancius ,&nbsp;Ben Tumulero ,&nbsp;Detmer Sipkema ,&nbsp;Diana Z. Sousa","doi":"10.1016/j.syapm.2025.126628","DOIUrl":"10.1016/j.syapm.2025.126628","url":null,"abstract":"<div><div>Thermophilic acetogens hold great potential for syngas fermentation, as they efficiently convert CO and H₂/CO₂ into added-value chemical building blocks. Among these, <em>Moorella</em> species are the most studied, known for their versatility by growing autotrophically on C1 gaseous compounds and heterotrophically on sugars and organic acids. In this study, we isolated two novel thermophilic CO-utilising acetogens belonging to the genus <em>Moorella</em>: strain AZ13.I, representing a novel species, and strain AZ24.1, which is closely related to <em>M. humiferrea</em>. We further investigated CO metabolism in this genus and found that all <em>Moorella</em> species isolated to date can utilise CO, contradicting earlier reports suggesting that the type strains of <em>M. humiferrea</em> (DSM 23265^T) and <em>M. mulderi</em> (DSM 14911^T) were incapable of metabolising this substrate. Finally, based on genomic analyses at the genus level, we suggest that CO metabolism is a universal trait across all <em>Moorella</em> species.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 4","pages":"Article 126628"},"PeriodicalIF":3.3,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144297924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Liberiplasma polymorphum gen. nov., sp. nov., a novel cell-wall-less free-living anaerobe, isolated from a terrestrial mud volcano, and proposal of Liberiplasmataceae fam. nov. and Liberiplasmatales ord. nov","authors":"M.A. Khomyakova ,&nbsp;A.Y. Merkel ,&nbsp;A.A. Novikov ,&nbsp;A.I. Slobodkin","doi":"10.1016/j.syapm.2025.126629","DOIUrl":"10.1016/j.syapm.2025.126629","url":null,"abstract":"<div><div>A novel anaerobic free-living bacterium (strain C05PYG^T) was isolated from a terrestrial mud volcano (Taman Peninsula, Russia). Cells were pleomorphic but mainly consisted of small, cell wall-less, non-motile cocci, 0.40–0.46 μm in diameter. The temperature range for growth was 5–37 °C (optimum at 30 °C). The pH range for growth was 7.5–10.0, with an optimum at pH 8.0–9.0. It was a chemoorganoheterotroph, fermenting mono-, di- and polysaccharides (dextrin, starch), proteinaceous substrates and organic acids (lactate and pyruvate). Yeast extract was essential for growth. Strain C05PYG^T possessed an ability to degrade extraneous DNA. Major cellular fatty acids were C_16:0 and i-C_17:0; major dimethyl acetals were C_14:0 DMA and i-C_15:0 DMA. The genome of strain C05PYG^T had a size of 2.0 Mb with a DNA G + C content of 33.0 % (WGS). Phylogenetic analysis based on 120 marker genes placed strain C05PYG^T in a separate order adjacent to the order <em>Acholeplasmatales</em> within the class <em>Mollicutes</em>, hitherto referred to as “<em>Izemoplasmatales</em>”, which contains no representatives with validly published names. We propose to assign strain C05PYG^T to a novel species of a novel genus, <em>Liberiplasma polymorphum</em> gen. nov., sp. nov.; the type strain is C05PYG^T (=VKM B-3767^T = BIM B-2060^T = UQM 41800^T). This genus is placed in a novel family, <em>Liberiplasmataceae</em> fam. nov. within the novel order <em>Liberiplasmatales</em> ord. nov<em>.,</em> class <em>Mollicutes</em>.</div></div>","PeriodicalId":22124,"journal":{"name":"Systematic and applied microbiology","volume":"48 4","pages":"Article 126629"},"PeriodicalIF":3.3,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144261618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}