Qingshengfaniella alkalisoli gen. nov., sp. nov., a p-hydroxybenzoate-degrading strain isolated from saline soil

Meridianimarinicoccus marinus sp. nov., Isolated from Tidal Flat

A novel bacterial strain, designated DFM31T, was isolated from a tidal flat in Gun-San, South Korea and characterized as a novel species within the genus Meridianimarinicoccus. Morphological and biochemical analyses indicated that strain DFM31T was a Gram-stain-negative, coccoid-shaped bacterium without flagella. The strain formed pale orange colonies on MA after 3 days of incubation at 30 °C. The strain was found to survive at 20-37 °C (optimum, 30 °C), pH 6-8 (optimum, pH 7), and 0.5-5% (w/v) NaCl (optimum, 3%). 16S rRNA gene similarity analysis indicated that the strain DFM31T was closely related to the genus Meridianimarinicoccus (95.1-97.5%). Biochemical tests showed that the strain was oxidase and catalase positive. The major fatty acids were Summed Feature 8 [C18:1 ω 7c/C18:1 ω 6c] (86.1%) and the major respiratory quinone was Q-10. The DNA G + C % of genomic DNA is 64.4. The values for Average amino acid (AAI), Average nucleotide identity (ANI), and DNA-DNA hybridization (DDH) compared with the related type strains in the genus Meridianimarinicoccus were 70.7-72%, 72.4-75.1%, and 18.7-19.2%, respectively. Based on its distinct phylogenetic, phenotypic, and biochemical characteristics, strain DFM31T is proposed to represent a novel species of the genus Meridianimarinicoccus, for which the name Meridianimarinicoccus marinus sp. nov. is proposed. The type strain is DFM31T (= KEMB 021938 T = KCTC 8650 T = JCM 37289 T).

Extensive genomic study characterizing three Paracoccaceae populations and revealing Pseudogemmobacter lacusdianii sp. nov. and Paracoccus broussonetiae sp. nov

Bacteria within the family Paracoccaceae show promising potential for applications in various fields, garnering significant research attention. Three Gram stain-negative bacteria, strains CPCC 101601T, CPCC 101403T, and CPCC 100767, were isolated from diverse environments: freshwater, rhizosphere soil of Broussonetia papyrifera, and the phycosphere, respectively. Analysis of their 16S rRNA gene sequences, compared with those in the GenBank database, indicated that they belong to the family Paracoccaceae, with nucleotide similarities of 92.5%-99.9% to all of the Paracoccaceae members with valid taxonomic names. Phylogenetic studies based on 16S rRNA gene and whole-genome sequences identified CPCC 101601T as a member of the genus Pseudogemmobacter, CPCC 101403T belonging to the genus Paracoccus, and CPCC 100767 as part of the genus Gemmobacter. Notably, genomic analysis using average nucleotide identity (ANI; <95%) and digital DNA-DNA hybridization (dDDH; <70%) with their closely related strains suggested that CPCC 101601T and CPCC 101403T represent new species within their respective genera. Conversely, CPCC 100767 exhibited high ANI (98.5%) and dDDH (87.4%) values with Gemmobacter fulvus con5T, indicating it belongs to this already recognized species. The in-depth genomic analysis revealed that strains CPCC 101601T, CPCC 101403T, and CPCC 100767 harbor key genes related to the pathways for denitrifying, MA utilization, and polyhydroxyalkanoate biosynthesis. Moreover, genotyping and phenotyping analysis confirmed that strain CPCC 100767 has the ability to convert atmospheric nitrogen into ammonia and produce 5-aminolevulinic acid, whereas CPCC 101601T can only perform the former bioprocess.IMPORTANCEBased on polyphasic taxonomic study, two new species, Pseudogemmobacter lacusdianii and Paracoccus broussonetiae, affiliated with the family Paracoccaceae were identified. This expands our understanding of the family Paracoccaceae and provides new microbial materials for further studies. Modern genomic techniques such as average nucleotide identity and digital DNA-DNA hybridization were utilized to determine species affiliations. These methods offer more precise results than traditional classification mainly based on 16S rRNA gene analysis. Beyond classification of these strains, the research delved into their genomes and discovered key genes related to denitrification, MA utilization, and polyhydroxyalkanoate biosynthesis. The identification of these genes provides a molecular basis for understanding the environmental roles of these strains. Particularly, strain CPCC 100767 demonstrated the ability to convert atmospheric nitrogen into ammonia and produce 5-aminolevulinic acid. These bioprocess capabilities are of significant practical value, such as in agricultural production for use as biofertilizers or biostimulants.

Genomic potential for inorganic carbon sequestration and xenobiotic degradation in marine bacterium Youngimonas vesicularis CC-AMW-ET affiliated to family Paracoccaceae

Ecological studies on marine microbial communities largely focus on fundamental biogeochemical processes or the most abundant constituents, while minor biological fractions are frequently neglected. Youngimonas vesicularis CC-AMW-ET, isolated from coastal surface seawater in Taiwan, is an under-represented marine Paracoccaceae (earlier Rhodobacteraceae) member. The CC-AMW-ET genome was sequenced to gain deeper insights into its role in marine carbon and sulfur cycles. The draft genome (3.7 Mb) contained 63.6% GC, 3773 coding sequences and 51 RNAs, and displayed maximum relatedness (79.06%) to Thalassobius litoralis KU5D5T, a Roseobacteraceae member. While phototrophic genes were absent, genes encoding two distinct subunits of carbon monoxide dehydrogenases (CoxL, BMS/Form II and a novel form III; CoxM and CoxS), and proteins involved in HCO3- uptake and interconversion, and anaplerotic HCO3- fixation were found. In addition, a gene coding for ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO, form II), which fixes atmospheric CO2 was found in CC-AMW-ET. Genes for complete assimilatory sulfate reduction, sulfide oxidation (sulfide:quinone oxidoreductase, SqrA type) and dimethylsulfoniopropionate (DMSP) cleavage (DMSP lyase, DddL) were also identified. Furthermore, genes that degrade aromatic hydrocarbons such as quinate, salicylate, salicylate ester, p-hydroxybenzoate, catechol, gentisate, homogentisate, protocatechuate, 4-hydroxyphenylacetic acid, N-heterocyclic aromatic compounds and aromatic amines were present. Thus, Youngimonas vesicularis CC-AMW-ET is a potential chemolithoautotroph equipped with genetic machinery for the metabolism of aromatics, and predicted to play crucial roles in the biogeochemical cycling of marine carbon and sulfur.

Ruania suaedae sp. nov. and Ruania halotolerans sp. nov., two actinobacteria isolated from saline soil, and reclassification of Haloactinobacterium kanbiaonis as Occultella kanbiaonis comb. nov

Two Gram-stain-positive, non-motile, strictly aerobic, yellow-coloured, rod-shaped bacterial strains, designated LR1S40T and M4N3S171T, were isolated from rhizosphere and bulk saline soil of Suaeda salsa collected in Inner Mongolia, China. Phylogenetic trees based on 16S rRNA gene and whole genome sequences showed that the two strains clustered tightly with strains of the genus Ruania . Strains LR1S40T and M4N3S171T had 95.5% 16S rRNA gene similarity to each other, and strain LR1S40T had 98.8, 98.7, 97.4 and <97.0% similarity to Ruania alkalisoli RN3S43T, Ruania rhizosphaerae LNNU 22110T, Ruania alba YIM 93306T and all other current type strains, while strain M4N3S171T had 98.6 and <97.0% similarity to R. alba YIM 93306T, and all other current type strains, respectively. The average nucleotide identity based on blast (ANIb) and digital DNA–DNA hybridization (dDDH) values of LR1S40T and M4N3S171T with each other and to the other type strains of Ruania were well below the threshold values (95% for ANIb, 70% for dDDH) for differentiating a species. Diphosphatidylglycerol and phosphatidylglycerol were the major polar lipids in both strains. The predominant menaquinone in both strains was both MK-8. The genome of strain LR1S40T consisted of a 3557440 bp circular chromosome, with a G+C content of 71.1 mol%, while the genome of strain M4N3S171T consisted of 4270413 bp, with a G+C content of 67.6 mol%. The phylogenetic, physiological and phenotypic characteristics allowed discrimination of the two strains from their relatives. The names Ruania suaedae sp. nov. [type strain LR1S40T (=CGMCC 1.19028T=KCTC 49726T)] and Ruania halotolerans sp. nov. [type strain M4N3S171T (=CGMCC 1. 19142T=KCTC 49727T)] are therefore proposed. During the publication of Haloactinobacterium kanbiaonis , Haloactinobacterium glacieicola (type strain T3246-1T), which was selected as the reference strain for the identification of H. kanbiaonis , was reclassified as Occultella glacieicola . The two phylogenetic trees showed that H. kanbiaonis HY164T tightly clustered with Occultella aeris F300T, and had the highest 16S rRNA gene similarity (99.8%) to O. aeris F300T. Based on the phylogenetic analysis and the publication record, Haloactinobacterium kanbiaonis should be reclassified as Occultella kanbiaonis comb. nov.

Marinilactibacillus kalidii sp. nov., an Indole Acetic Acid-Producing Endophyte Isolated from a Shoot of Halophyte Kalidium cuspidatum

A Gram-stain-positive, facultatively anaerobic, non-sporulating, motile with single polar flagellum, rod-shaped, indole-3-acetic acid (IAA)-producing bacterium, named M4U5P12^T, was isolated from a shoot of Kalidium cuspidatum, Inner Mongolia, China. Strain M4U5P12^T grew at pH 6.0-11.0 (optimum 7.5), 4-40 °C (optimum 25 °C), and in the presence of 0-15% (w/v) NaCl (optimum 4%). Positive for catalase, urease, methyl red (M.R.) reaction, and hydrolysis of starch; and negative for oxidase, Voges-Proskauer (V-P) test, and hydrolysis of cellulose. The phylogenetic trees based on the 16S rRNA gene sequences and the whole genome sequences both revealed that it clustered with Marinilactibacillus piezotolerans JCM 12337^T (99.3%) and Marinilactibacillus psychrotolerans M13-2^T (99.1%). The dDDH and ANIb values of strain M4U5P12^T to M. piezotolerans DSM 16108^T and M. psychrotolerans M13-2^T were 19.3 and 18.9%, and 74.3 and 74.0%, respectively. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid, and two unidentified lipids. The major fatty acids were C_16:0, C_18:1 ω9c, C_16:1 ω9c, and C_15:1 ω5c. The genomic DNA G + C content was 37.3%. On the basis of physiological, phenotypic, and phylogenetic characteristics, strain M4U5P12^T should be classified as a novel species. Therefore, Marinilactibacillus kalidii sp. nov. is proposed, and the type strain is M4U5P12^T (= CGMCC 1.17696^T = KCTC 43247^T).

Gracilibacillus suaedae sp. nov., an indole acetic acid-producing endophyte isolated from a root of Suaeda salsa

A Gram-stain-positive, facultatively anaerobic, spore-forming, motile with unipolar biflagella, rod-shaped, indole acetic acid-producing bacterium, named LD4P30^T, was isolated from a root of Suaeda salsa collected in Inner Mongolia, northern China. Strain LD4P30^T grew at pH 6.0-11.0 (optimum, pH 7.0), 10-40 °C (35 °C) and in the presence of 1-15% (w/v) NaCl (5%). The strain was positive for oxidase and negative for catalase. The major cellular fatty acids of strain LD4P30^T were iso-C_15:0, C_15:1 ω5c and anteiso-C_15:0; the major polar lipids were diphosphatidylglycerol and phosphatidylglycerol; and menaquinone-7 was the only respiratory quinone. The genomic DNA G+C content was 36.7 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain LD4P30^T clustered with Gracilibacillus thailandensis TP2-8^T, Gracilibacillus saliphilus YIM 91119^T and Gracilibacillus lacisalsi BH312^T, and showed 99.0, 98.9, 98.0 and <97.7% 16S rRNA gene similarity to G. thailandensis TP2-8^T, G. saliphilus YIM 91119^T, G. lacisalsi BH312^T and all other current type strains, respectively. The digital DNA-DNA hybridization and average nucleotide identity based on blast values between strain LD4P30^T and G. saliphilus YIM 91119^T, G. thailandensis TP2-8^T and G. lacisalsi BH312^T were 44.9, 44.7 and 44.4%, and 91.1, 91.0 and 90.8%, respectively. Based on its phenotypic, physiological and phylogenetic characteristics, strain LD4P30^T represents a novel species, for which the name Gracilibacillus suaedae is proposed. The type strain is LD4P30^T (=CGMCC 1.17697^T=KCTC 82375^T).