Discovery of a Novel Chromone Enantiomer and the Precursors of Nonactic Acid from the Coral-Reef-Derived Streptomyces sp. SCSIO 66814.

Three pairs of enantiomers (1-3)-the new 12R-aloesol (1a) and two new fatty acids (2 and 3)-and one new natural product (4) together three known compounds (5-7) were isolated from a coral-reef-derived Streptomyces sp. SCSIO 66814. Their structures were determined through extensive spectroscopic analysis, chiral analysis, and single-crystal X-ray diffraction data. Compounds 2 and 3 were presumed to be intermediates for further generating homononactic acid (5) and nonactic acid, and the latter two molecules were able to act as precursors to form macrotetrolides with remarkable biological activity. The isolation of related precursors, compounds 2-5, provided more evidence to support the proposal of a plausible biosynthetic pathway for nonactic acid and its homologs. Additionally, (+)-1 exhibited a weak activity against DPPH radicals.

Genome-guided discovery of two undescribed 6,6-spiroketal polyketides and stereochemical correction of bafilomycins P and Q from the marine-derived Streptomyces sp. SCSIO 66814.

Bafilomycins are macrocyclic polyketides with intriguing structures and therapeutic value. Genomic analysis of Streptomyces sp. SCSIO 66814 revealed a type I polyketide synthase biosynthetic gene cluster (BGC), namely blm, which encoded bafilomycins and featured rich post-modification genes. The One strain many compounds (OSMAC) strategy led to the discovery of six compounds related to the blm BGC from the strain, including two previously undescribed 6,6-spiroketal polyketides, streptospirodienoic acids D (1) and E (2), and four known bafilomycins, bafilomycins P (3), Q (4), D (5), and G (6). The structures of 1 and 2 were determined by extensive spectroscopic analysis, quantum calculation, and biosynthetic analysis. Additionally, the absolute configurations of the 6/5/5 tricyclic ring moiety containing six consecutive chiral carbons in the putative structures of 3 and 4 were corrected through NOE analysis, DP4+ calculation, and single-crystal X-ray diffraction data. Bioinformatic analysis uncovered a plausible biosynthetic pathway for compounds 1-6, indicating that both streptospirodienoic acids and bafilomycins were derived from the same blm BGC. Additionally, sequence analysis revealed that the KR domains of module 2 from blm BGC was B1-type, further supporting the configurations of 1-4. Notably, compounds 3 and 4 displayed significant cytotoxic activities against A-549 human non-small cell lung cancer cells and HCT-116 human colon cancer cells.

Polyethylene Terephthalate Hydrolases in Human Gut Microbiota and Their Implications for Human Health.

Polyethylene terephthalate (PET), primarily utilized for food and beverage packaging, consistently finds its way into the human gut, thereby exerting adverse effects on human health. PET hydrolases, critical for the degradation of PET, have been predominantly sourced from environmental microbial communities. Given the fact that the human gut harbors a vast and intricate consortium of microorganisms, inquiry into the presence of potential PET hydrolases within the human gut microbiota becomes imperative. In this investigation, we meticulously screened 22,156 homologous sequences that could potentially encode PET hydrolases using the hidden Markov model (HMM) paradigm, drawing from 4984 cultivated genomes of healthy human gut bacteria. Subsequently, we methodically validated the hydrolytic efficacy of five selected candidate PET hydrolases on both PET films and powders composed of micro-plastics (MPs). Notably, our study also unveiled the influence of both diverse PET MP powders and their resultant hydrolysates on the modulation of cytokine expression in macrophages. In summary, our research underscores the ubiquitous prevalence and considerable potential of the human gut microbiota in PET hydrolysis. Furthermore, our study significantly contributes to the holistic evaluation of the potential health hazards posed by PET MPs to human well-being.

Paenimyroides aestuarii gen. nov. sp. nov., a novel bacterium isolated from sediment in the Pearl River Estuary and reclassification of five Flavobacterium and four Myroides species.

An aerobic, Gram-negative, non-motile, yellow-to-orange pigmented and round bacterium, designated strain SCSIO 72103T, was isolated from sediment collected in the Pearl River Estuary, Guangdong Province, PR China and subjected to a polyphasic taxonomic study. Growth occurred at 20-37 °C (optimum, 28 °C), pH 6-8 (optimum, pH 7) and with 1-5.5% NaCl (optimum, 1-3 %). Comparative 16S rRNA gene analysis indicated that strain SCSIO 72103T had the highest similarities to Flavobacterium baculatum SNL9T (94.7 %) and Myroides aquimaris SW105T (94.2 %). Phylogenetic analysis based 16S rRNA gene sequences showed that strain SCSIO 72103T formed a single clade with M. aquimaris SW105T. Strain SCSIO 72103T contained iso-C15 : 0 as the major fatty acid and the predominant respiratory quinone was menaquinone MK-6. These characteristics are consistent with those of F. baculatum SNL9T and M. aquimaris SW105T. Phosphatidylethanolamine, most notably, unidentified aminolipid and unidentified aminophospholipid were major polar lipids. Strain SCSIO 72103T had a single circular chromosome of 2.96 Mb with a DNA G+C content of 35.1 mol%. The average nucleotide identity, average amino acid identity (AAI) and digital DNA-DNA hybridization values showed that the pairwise similarities between SCSIO 72103T and the type strains of F. baculatum SNL9T and M. aquimaris SW105T were 78.5-80.5 %, 79.0-81.4 % and 22.7-22.8 %, respectively. The AAI values between species in this clade and the type species of Flavobacterium and Myroides were below the 65 % threshold, indicating that these species belong to a novel genus. On the basis of phylogenetic, physiological and chemotaxonomic characteristics, strain SCSIO 72103T represents a new species of a novel genus, for which the name Paenimyroides aestuarii gen. nov. sp. nov. is proposed. The type strain is SCSIO 72103T (=KCTC 92043T=MCCC 1K06659T). It is also proposed that nine known species in the genera Flavobacterium and Myroides are reclassified as Paenimyroides species.

Three Novel Marine Species of Paracoccus, P. aerodenitrificans sp. nov., P. sediminicola sp. nov. and P. albus sp. nov., and the Characterization of Their Capability to Perform Heterotrophic Nitrification and Aerobic Denitrification.

Heterotrophic nitrification-aerobic denitrification (HN-AD) is an efficient nitrogen removal process and the genus Paracoccus is one important group of the HN-AD bacteria. During an investigation of the microbial diversity in marine ranching of the Pearl River Estuary (PR China), three bacterial strains, designated SCSIO 75817T, SCSIO 76264T and SCSIO 80058T, were isolated from sediments. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the three strains belonged to the genus Paracoccus and their closest neighbors were P. isoporae DSM 22220T (97.6-98.0%), P. aurantiacus CGMCC 1.13898T (97.3-97.6%) and P. xiamenensis MCCC 1A16381T (97.1-97.4%), respectively. The analysis results of 16S rRNA gene similarity, ANI, AAI and dDDH showed that the pairwise similarities between these three strains and their closest neighbors were 97.4-98.5%, 76.9-81.0%, 75.5-79.6% and 20.3-23.3%, respectively. Polyphasic taxonomic data of the phylogenetic, phenotypic and chemotaxonomic analyses indicate that these strains represent three novel species in the genus Paracoccus, for which the names Paracoccus aerodenitrificans sp. nov., Paracoccus sediminicola sp. nov. and Paracoccus albus sp. nov. are proposed, respectively. The study also demonstrated the heterotrophic nitrification-aerobic denitrification (HN-AD) ability of the novel species P. aerodenitrificans SCSIO 75817T. When it was aerobically cultivated at 28 °C using NH4+-N, NO3--N and NO2--N as the sole nitrogen sources, the nitrogen removal efficiencies were 73.4, 55.27 and 49.2%, respectively, and the maximum removal rates were 3.05, 1.82 and 1.63 mg/L/h, respectively. The results suggest that it has promising potential for wastewater treatment.

Halo- and Thiocarbazomycins from Coral- and Coral Reef Sands-Derived Actinomycetes.

Four actinomycete strains isolated from the coral Acropora austera and coral sand samples from the South China Sea, were found to produce a series of halogenated compounds baring similar ultraviolet absorption based on the analysis of HPLC and LC-MS. The production titers of halogenated compounds from Streptomyces diacarni SCSIO 64983 exceeded those of other similar strains leading us to focus on SCSIO 64983. Four new thiocarbazomycins A-B (1-2), chlocarbazomycin E (3), and brocarbazomycin A (4), together with three known chlocarbazomycins A-C (5-7) containing a carbazole core were identified, and their structures were determined using a combination of spectroscopic analysis including HRESIMS, 1D and 2D NMR. Structurally speaking, compounds 1 and 2 have the rare sulfur-containing carbazole nuclei, and 3 and 4 contain Cl and Br atoms, respectively. Although these compounds have not yet been found to have obvious biological activity, their discovery highlights the role of molecular libraries in subsequent drug discovery campaigns.

Streptomyces marincola sp. nov., a Novel Marine Actinomycete, and Its Biosynthetic Potential of Bioactive Natural Products.

Marine actinomycetes are an important source of antibiotics, but many of them are yet to be explored in terms of taxonomy, ecology, and functional activity. In this study, two marine actinobacterial strains, designated SCSIO 64649T and SCSIO 03032, were isolated, and the potential for bioactive natural product discovery was evaluated based on genome mining, compound detection, and antimicrobial activity. Phylogenetic analysis of the 16S rRNA gene sequences showed that strain SCSIO 64649T formed a single clade with SCSIO 03032 (similarity 99.5%) and sister clades with the species Streptomyces specialis DSM 41924T (97.1%) and Streptomyces manganisoli MK44T (96.8%). The whole genome size of strain SCSIO 64649T was 6.63 Mbp with a 73.6% G + C content. The average nucleotide identity and digital DNA-DNA hybridization between strain SCSIO 64649T and its closest related species were well below the thresholds recommended for species delineation. Therefore, according to the results of polyphasic taxonomy analysis, the strains SCSIO 64649T and SCSIO 03032 are proposed to represent a novel species named Streptomyces marincola sp. nov. Furthermore, strains SCSIO 64649T and 03032 encode 37 putative biosynthetic gene clusters, and in silico analysis revealed that this new species has a high potential to produce unique natural products, such as a novel polyene polyketide compounds, two mayamycin analogs, and a series of post-translationally modified peptides. In addition, other important bioactive natural products, such as heronamide F, piericidin A1, and spiroindimicin A, were also detected in strain SCSIO 64649T. Finally, this new species' metabolic crude extract showed a strong antimicrobial activity. Thanks to the integration of all these analyses, this study demonstrates that the novel species Streptomyces marincola has a unique and novel secondary metabolite biosynthetic potential that not only is beneficial to possible marine hosts but that could also be exploited for industrial applications.

Nocardioides coralli sp. nov., an actinobacterium isolated from stony coral in the South China Sea.

A Gram-stain-positive, aerobic, non-pigmented and non-motile actinobacterium, designated strain SCSIO 67246T, was isolated from a stony coral sample collected from the Sanya sea area, Hainan province, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SCSIO 67246T shared the highest similarities with Nocardioides rotundus MCCC 1A10561T (96.5 %) and Nocardioides sonneratiae KCTC 39565T (96.1%). The novel strain grew at 15-37 °C, at pH 5.0-10.0 and in the presence of 0-10 % (w/v) NaCl. The genome length of strain SCSIO 67246T was 3.52 Mbp with a DNA G+C content of 72.0 mol% and 3397 protein-coding genes. The novel strain showed an average nucleotide identity value of 76.5 % and a digital DNA-DNA hybridization value of 20.1 % with N. rotundus MCCC 1A10561T. Strain SCSIO 67246T contained MK-8(H4) as the major menaquinone. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and five phospholipids. The major cellular fatty acids were iso-C16 : 0, C17 : 1 ω8c and summed feature 9 (iso-C17 : 1 ω9c/10-methyl C16 : 0). ll-2,6-Diaminopimelic acid was the diagnostic diamino acid. The whole-cell sugars were galactose, glucose and ribose. Based on this polyphasic taxonomic study, strain SCSIO 67246T represents a novel species of the genus Nocardioides, for which the name Nocardioides coralli sp. nov. is proposed. The type strain is SCSIO 67246T (=MCCC 1K06251T=KCTC 49719T).

Pontibacter qinzhouensis sp. nov., isolated from rhizosphere soil of a mangrove plant Rhizophora stylosa.

A novel bacterium of the genus Pontibacter, designated GY10130T, was isolated from rhizosphere soil of a mangrove plant Rhizophora stylosa collected from Guangxi province, China. Strain GY10130T was Gram-stain negative, positive for oxidase activities, aerobic, short rod-shaped cells without flagella. Growth was observed at 10-40 °C (optimum, 28 °C), pH 6.0-9.0 (optimum, 7.0) and NaCl concentrations of 0-4% (optimum, 1%). Strain GY10130T is closely related to members of the genus Pontibacter, namely P. beigongshangensis CGMCC 1.17104T (97.8%) and P. amylolyticus CGMCC 1.12749T (95.0%), P. humi SWU8T (94.7%), and less than 94.0% with other currently described type strains of Pontibacter. The strain GY10130T showed an ANI value of 80.6% and dDDH value of 23.2% with P. beigongshangensis CGMCC 1.17104T, followed by P. amylolyticus CGMCC 1.12749T with ANI and dDDH values of 72.9 and 13.8%, respectively. Strain GY10130T contains carotenoid-like pigments, but flexirubin-type pigments were absent. The cellular fatty acids (> 10%) consist of summed feature 4 (17:1 iso I/anteiso B) and iso-C15:0. The predominant menaquinone is MK-7. The polar lipids comprise phosphatidylethanolamine, two unidentified glycolipids, two unidentified aminolipids and six unidentified phospholipids. The genome length of strain GY10130T was 6.2 Mbp with a DNA G + C content of 47.1 mol% and 4727 protein-coding genes. The result of polyphasic taxonomic study show strain GY10130T represents one novel species of Pontibacter, Pontibacter qinzhouensis sp. nov., with the type strain GY10130T (=NBRC 113901T = CGMCC 1.16772T).

Diversity and Distribution of Uncultured and Cultured Gaiellales and Rubrobacterales in South China Sea Sediments.

Actinobacteria are ubiquitous in marine ecosystems, and they are regarded as an important, underexplored, potential pharmaceutical resource. The orders Gaiellales and Rubrobacterales are deep taxonomic lineages of the phylum Actinobacteria, both are represented by a single genus and contain only a few species. Although they have been detected frequently by high-throughput sequencing, their functions and characteristics in marine habitats remain unknown due to the lack of indigenous phenotypes. Here, we investigated the status of the orders in South China Sea (SCS) sediments using culture-independent and culture-dependent methods. Gaiellales is the second-most abundant order of Actinobacteria and was widely distributed in SCS sediments at water depths of 42-4,280 m, and four novel marine representatives in this group were successfully cultured. Rubrobacterales was present at low abundance in energy-limited marine habitats. An isolation strategy for Rubrobacterales from marine samples was proposed, and a total of 138 mesophilic Rubrobacterales strains were isolated under conditions of light and culture time combined with high-salinity or low-nutrient media. Marine representatives recovered in this study formed branches with a complex evolutionary history in the phylogenetic tree. Overall, the data indicate that both Gaiellales and Rubrobacterales can adapt to and survive in extreme deep-sea environments. This study lays the groundwork for further analysis of the distribution and diversity of the orders Gaiellales and Rubrobacterales in the ocean and provides a specific culture strategy for each group. The results open a window for further research on the ecological roles of the two orders in marine ecosystems.

Flavimobilis rhizosphaerae sp. nov., isolated from rhizosphere soil of Spartina alterniflora.

A novel Gram-stain positive, facultatively anaerobic, motile, irregularly rod-shaped bacterium, designated GY 10621T, was isolated from rhizosphere soil of Spartina alterniflora in Beihai City, Guangxi Province, PR China, and characterized using a polyphasic taxonomic approach. GY 10621T was positive for catalase and oxidase. Growth occurred at 4-42 °C (optimum 30-37 °C), at pH 5.0-9.0 (optimum pH 7.0) and in the presence of 0-5% NaCl (w/v) (optimum 1-3%). The main menaquinones were MK-9 (H4) (92.2 %) and MK-10 (7.8 %). The major cellular fatty acids were anteiso-C15 : 0 and C14 : 0. The peptidoglycan was the type A4α (l-Lys-Ser-d-Glu). The polar lipids included four phosphoglycolipids, four glycolipids, an unidentified lipid and six unidentified phospholipids. The DNA G+C content of the type strain was 71.7 mol%. On the basis of the results of 16S rRNA gene analysis, the type strain of a species with a validly published name with the highest similarity to GY 10621T was Flavimobilis soli KCTC 13155T (97.16 %), followed by Sanguibacter suarezii NBRC 16159T (96.39 %). The calculated results indicated that compared with GY 10621T, the average nucleotide identity (ANI) values of three strains closely related to GY 10621T (the two aforementioned type strains and 'S. massiliensis' Marseille-P3815) were 74.18-94.97 %, and the digital DNA-DNA hybridization (dDDH) values were 20.3-60.6 %. The results of 16S rRNA-based and genome-based phylogenetic tree analysis indicated that GY 10621T should be assigned to the genus Flavimobilis. On the basis of evidence from polyphasic studies, GY 10621T should be designated as representing a novel species of the genus Flavimobilis, for which the name Flavimobilis rhizosphaerae sp. nov. is proposed. The type strain is GY 10621T (=CGMCC 1.17411T=KCTC 49515T).

Crenobacter intestini sp. nov., Isolated from the Intestinal Tract of Konosirus punctatus.

A novel Gram-stain-negative bacterium, designated strain GY 70310T, was isolated from the intestinal tract of Konosirus punctatus collected from Minjiang River, China. Cells of the strain were rod-shaped and motile with a single polar flagellum. The result of 16S rRNA gene sequence analyses showed that strain GY 70310T was moderately related to Crenobacter luteus YIM 78141T (94.7%), Paludibacterium paludis KBP-21T (93.8%) and Crenobacter cavernae K1W11S-77T (93.0%). The draft genome of strain GY 70310T consisted of 3.4 Mbp with DNA G+C content of 66.3 mol%, which possessed genes putatively encoding nitrate reductase, nitrite oxidoreductase and urease. The novel strain showed a whole genome average nucleotide identity (OrthoANI) value of 77.1% and a digital DNA-DNA hybridization (dDDH) value of 22.4% with Crenobacter luteus DSM 27258T, followed by Crenobacter cavernae K1W11S-77T with OrthoANI and dDDH values of 76.4% and 20.6%, respectively. The major fatty acids (>10%) were identified as summed feature 3 (C16:1ω6c and/or iso-C15:0 2-OH, C16:1ω7c), C16:0 and C18:1ω7c. The major respiratory quinone was ubiquinone-8 (Q-8). The polar lipids comprised diphosphatidylglycerol, phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified lipid and one unidentified phospholipid. On the basis of phylogenetic analyses, genotypic and chemotaxonomic characteristics, strain GY 70310T represents a novel species of the genus Crenobacter, for which the name Crenobacter intestini sp. nov., is proposed. The type strain is GY 70310T (= CGMCC 1.16821T = KCTC 62945T = NBRC 113900T).

Actinomarinicola tropica gen. nov. sp. nov., a new marine actinobacterium of the family Iamiaceae, isolated from South China Sea sediment environments.

A novel marine actinobacterium, strain SCSIO 58843T, was isolated from the sediment sample collected from the South China Sea. Strain SCSIO 58843T was Gram-stain-positive, aerobic and rod shaped. The whole-cell hydrolysis of amino acids contained dd-DAP, alanine, glutamic acid, glycine and aspartic acid. The main menaquinone was MK-9(H8). The major fatty acids were C17 : 1 ω8c and C17 : 0. The major phospholipids were diphosphatidylglycerol (DPG), phosphatidylinositol (PI), phospatidylcholine (PC) and phosphatidylinositolmannoside (PIM). The G+C content of the genomic DNA was 72.5 %. Phylogenetic analysis of the 16S rRNA gene sequences showed that strain SCSIO 58843T formed a new lineage in the family Iamiaceae and had the highest similarity of 93.8 % with Iamia majanohamensis DSM 19957T. Strain SCSIO 58843T can be distinguished from these known genera in the family Iamiaceae by polyphasic data analyses, and represents a novel genus and novel species, for which Actinomarinicola tropica gen. nov., sp. nov is proposed with the type strain SCSIO 58843T(=KCTC 49408T=CGMCC 1.17503T).

Cloning, expression and characterization of a chitinase from Paenibacillus chitinolyticus strain UMBR 0002.

BACKGROUND: Chitinases are enzymes which degrade ß-1,4-glycosidid linkages in chitin. The enzymatic degradation of shellfish waste (containing chitin) to chitooligosaccharides is used in industrial applications to generate high-value-added products from such waste. However, chitinases are currently produced with low efficiency and poor tolerance, limiting the industrial utility. Therefore, identifying chitinases with higher enzymatic activity and tolerance is of great importance. METHODS: Primers were designed using the genomic database of Paenibacillus chitinolyticus NBRC 15660. An exochitinase (CHI) was cloned into the recombinant plasmid pET-22b (+) to form pET-22b (+)-CHI, which was transformed into Escherichia coli TOP10 to construct a genomic library. Transformation was confirmed by colony-polymerase chain reaction and electrophoresis. The target sequence was verified by sequencing. Recombinant pET-22b (+)-CHI was transformed into E. coli Rosetta-gami B (DE3) for expression of chitinase. Recombinant protein was purified by Ni-NTA affinity chromatography and enzymatic analysis was carried out. RESULTS: The exochitinase CHI from P. chitinolyticus strain UMBR 0002 was successfully cloned and heterologously expressed in E. coli Rosetta-gami B (DE3). Purification yielded a 13.36-fold enrichment and recovery yield of 72.20%. The purified enzyme had a specific activity of 750.64 mU mg-1. The optimum pH and temperature for degradation of colloidal chitin were 5.0 and 45 °C, respectively. The enzyme showed high stability, retaining >70% activity at pH 4.0-10.0 and 25-45 °C (maximum of 90 min). The activity of CHI strongly increased with the addition of Ca2+, Mn2+, Tween 80 and urea. Conversely, Cu2+, Fe3+, acetic acid, isoamyl alcohol, sodium dodecyl sulfate and ß-mercaptoethanol significantly inhibited enzyme activity. The oligosaccharides produced by CHI from colloidal chitin exhibited a degree of polymerization, forming N-acetylglucosamine (GlcNAc) and (GlcNAc)2 as products. CONCLUSIONS: This is the first report of the cloning, heterologous expression and purification of a chitinase from P. chitinolyticus strain UMBR 0002. The results highlight CHI as a good candidate enzyme for green degradation of chitinous waste.

Aureimonas leprariae sp. nov., Isolated from a Lepraria sp. Lichen.

A Gram-negative, motile, aerobic and coccoid rod-shaped bacterium, designated strain YIM132180T, was isolated from a Lepraria sp. lichen collected from Pu'er, Yunnan Province, China. The strain grew at 15-35 °C (optimum, 25-28 °C), at 0-2% (w/v) NaCl (optimum, 0-1%) and at pH 6.0-9.0 (optimum, pH 7.0). The 16S rRNA gene sequence showed that strain YIM132180T had highest similarity (96.4%) with Aureimonas endophytica 2T4P-2-4T, followed by Aureimonas ureilytica NBRC 106430T (95.7%) and Aureimonas rubiginis CC-CFT034T (95.6%). Phylogenetic analysis showed that the strain grouped with species of the genus Aureimonas. The genomic sequence was 4,779,519 bp and contained 4584 coding sequences (CDSs), 54 RNA genes, 3 complete rRNA genes and 47 tRNA genes. The major fatty acids (>10%) of strain YIM132180T were C18:1ω7c, C-16:0 and C19:0 cyclo ω8c. The predominant menaquinone was ubiquinone 10 (Q-10). The polar lipid profile comprised diphosphatidylglycerol, phosphatidylcholine, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, unidentified phospholipid, amino lipid, lipid and most importantly sulfoquinovosyldiacylglycerol (SQDG). Based on the draft genome sequence, the G +C content of strain YIM132180T was 68.4 mol%. The results of the polyphasic taxonomic study, including phenotypic, chemotaxonomic, and phylogenetic analyses, showed that strain YIM132180T represents a novel species of the genus Aureimonas, for which the name Aureimonas leprariae sp. nov. is proposed. The type strain is YIM 132180T (=KCTC 72462T = CGMCC 1.17389T).

Naasia lichenicola sp. nov., an actinobacterium isolated from lichen.

A Gram-stain-positive, yellow-pigmented, catalase-positive and oxidase-negative, strictly aerobic actinobacterium, designated strain YIM 131853T, was isolated from lichen collected from the South Bank of the Baltic Sea. The novel strain was non-spore-forming, short rod-shaped and motile with a single polar flagellum. The strain could grow at 4-37 °C (optimum, 28 °C), at pH 4.0-12.0 (pH 6.0) and at 0-3 % (w/v) NaCl (1 %). The DNA G+C content of strain YIM 131853T based on the draft genome sequence was 68.3 mol%. Predominant cellular fatty acids (>10 %) were identified as anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The polar lipid profile included diphosphatidylglycerol, dimannosyldiacylglycerol, three unknown glycolipids, two unknown phospholipids and one unknown lipid. Strain YIM 131853T had 2,4-diaminobutyric acid as the diagnostic cell-wall diamino acid, galactose and glucose as whole-cell sugars, and MK-10, MK-14, MK-13 and MK-12 as the major menaquinones. Although strain YIM 131853T exhibited a highest 16S rRNA gene sequence similarity (96.6 %) to Amnibacterium kyonggiense NBRC 109360T, phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain formed a tight lineage with Naasia aerilata NBRC 108725T (96.5 % 16S rRNA gene sequence similarity), which was the only species of genus Naasia. Based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, strain YIM 131853T should belong to the genus Naasia and represents a novel species of the genus Naasia, for which the name Naasia lichenicola sp. nov. is proposed. The type strain is YIM 131853T (=CGMCC 4.7565T=NBRC 113605T).

Rubellimicrobium rubrum sp. nov., a novel bright reddish bacterium isolated from a lichen sample.

A novel strain, YIM 131921T, was isolated from a Physcia sp. lichen collected from the South Bank Forest of the Baltic Sea. The strain is Gram-negative, catalase positive and oxidase negative, strictly aerobic, asporogenous, non-motile and reddish brown in colour. The temperature and pH for growth were found to be 20-30 °C (optimum 28 °C) and pH 6.5-12.0 (optimum pH 7.0 ± 0.5). No growth was observed in the presence of NaCl. Based on 16S rRNA gene sequence similarity, strain YIM 131921T shares high similarities with Rubellimicrobium roseum YIM 48858T (98.3%), followed by Rubellimicrobium mesophilum MSL-20T (96.8%), Rubellimicrobium aerolatum 5715S-9T (96.1%) and Rubellimicrobium thermophilum DSM 16684T (96.0%). Phylogenetic trees showed YIM 131921T forms a cluster with type strains of the genus Rubellimicrobium. The predominant cellular fatty acids (> 20%) were identified as summed feature 8 (C18:1ω7c) and C16:0. Q-10 was found to be the predominant respiratory ubiquinone. The polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, glycolipid, phospholipids and an unidentified aminolipid. The DNA G + C content of the draft genome sequence is 66.6 mol%. Strain YIM 131921T showed an average nucleotide identity value of 80.3% and a digital DNA-DNA hybridizations value of 26.1% with the reference strain R. roseum YIM 48858T based on draft genome sequences. Based on comparative analyses of phenotypic, molecular, chemotaxonomic data and genomic comparisons, strain YIM 131921T is concluded to represent a novel species of the genus Rubellimicrobium, for which the name Rubellimicrobium rubrum sp. nov. is proposed. The type strain is YIM 131921T (= CGMCC 1.13958T = NBRC 114054T = KCTC 72461T).

Ottowia flava sp. nov., isolated from fish intestines.

A novel Gram-negative bacterium, non-motile and short rod-shaped, designated strain GY511T, was isolated from the intestines of fish collected from Maowei Sea, China. Growth occurred at pH 6.0-9.0 (optimum 7.0), 4-37 °C (optimum 28 °C) and at 0-2.5% (w/v) NaCl (optimum 1.0%). The result of 16S rRNA gene sequence analysis showed that strain GY511T is closely related to O. oryzae NBRC 113109T (97.6%), O. konkukae DSM 105395T (97.4%), Ottowia beijingensis CGMCC 1.12324T (95.9%), Ottowia pentelensis DSM 21699T (95.2%) and Ottowia thiooxydans DSM 14619T (95.0%). The DNA-DNA hybridization values of strain GY511T with O. oryzae NBRC 113109T and O. konkukae DSM 105395T were 35.4 ± 3.1% and 26.3 ± 1.8%, respectively. The major fatty acids (> 10%) were identified as summed feature 3 (C16:1ω7c and/or C16:1ω6c), C16:0 and summed feature 8 (C18:1ω7c and/or C18:1ω6c) and the major respiratory quinone was ubiquinone-8 (Q-8). The polar lipids comprised diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanolamine, two unidentified aminolipids and an unidentified phospholipid. The G+C content of the genomic DNA was 62.9 mol%. Thiosulfate could be utilized as co-substrate for aerobic growth and was oxidised to sulfate. On the basis of phenotypic, chemotaxonomic and molecular data, strain GY511T is considered to represent a novel species of the genus Ottowia, for which the name Ottowia flava sp. nov. is proposed. The type strain is GY511T (= NBRC 113500T = DSM 107425T = CGMCC 1.13650T).

Flavobacterium viscosus sp. nov. and Flavobacterium tangerina sp. nov., from Primates Feces.

Strains YIM 102796T and YIM 102701-2T were isolated from the feces of Macaca mulatta and Hylobates hoolock, respectively, living in the Yunnan Wild Animal Park, Yunnan province of China. The two strains were Gram-stain-negative, non-gliding, produced flexirubin pigments, non-flagellated and aerobic bacteria. The 16S rRNA gene-based phylogenetic analysis indicate that both YIM 102796T and YIM 102701-2T are members of the genus Flavobacterium, closely related to F. ummariense DS-12T (95.9% similarity) and F. ceti 454-2T (93.8% similarity), respectively. The two strains shared 95.1 % 16S rRNA gene sequence similarity. The average nucleotide identity and digital DNA-DNA hybridization values between the two strains were 76.5% and 22.9%, respectively, indicating that they are separate species. DNA G+C contents of YIM 102796T and YIM 102701-2T were 32.3 mol% and 34.0 mol%, respectively. Strains are able to grow at 4-37 °C, at pH 7.0-8.0 and in 0-2% (w/v) NaCl. Predominant fatty acid constituents (>7 %) were iso-C15:0, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and summed feature 9 (iso-C17:1ω9c and/or 10-methylC16:0). Menaquinone 6 is major respiratory quinone. The predominant polar lipids were very similar to each other, comprising phosphatidylethanolamine, and multiple unknown aminolipids and unidentified polar lipids, and an unidentified aminophospholipid. On the basis of phenotypic and phylogenetic distinctiveness, it is suggested that the two strains represent two novel Flavobacterium species with strain YIM 102796T (=KCTC 52101T=CCTCC AB 2016015T) as the type strain of Flavobacterium viscosus sp. nov. and strain YIM 102701-2T (=KCTC 52100T=CCTCC AB 2016028T) as the type strain of Flavobacterium tangerina sp. nov.

Falsibacillus albus sp. nov., isolated from mangrove soil.

A novel Gram-stain-positive, catalase- and oxidase-positive, endospore-forming bacterium, designated GY 10110T, was isolated from mangrove soil collected from Qinzhou, Guangxi province, China. Cells were aerobic, motile with peritrichous flagella and rod-shaped. The strain grew at 15-37 °C (optimum, 28 °C), at 0-3 %(w/v) NaCl (1 %) and at pH 6.0-9.0 (pH 7.0). The major fatty acids of strain GY 10110T were anteiso-C15 : 0, iso-C15 : 0 and iso-C16 : 0. The predominant menaquinone was MK-7. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The polar lipid profile comprised diphosphatidylglycerol, phosphatidylethanolamine, phosphoglycolipid, glycolipid, two unidentified aminophospholipids and three unidentified phospholipids. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain GY 10110T was closely related to Falsibacillus pallidus CCTCC AB 207188T (98.0 % sequence similarity) and Bacillus oceanisediminis CGMCC 1.10115T (96.9 %), respectively. The G+C content of strain GY 10110T based on the whole genome sequence was 42.3 mol%. The novel strain showed an average nucleotide identity (ANI) value of 77.8 % and a digital DNA-DNA hybridization (dDDH) value of 15.6 % with Falsibacillus pallidus CCTCC AB 207188T based on draft genome sequences, followed by Bacillus oceanisediminis CGMCC 1.10115T with ANI and dDDH values of 75.2 and 12.8 %, respectively. The results of the polyphasic taxonomic study, including phenotypic, chemotaxonomic and phylogenetic analysis, showed that strain GY 10110T represents a novel species of the genus Falsibacillus, for which the name Falsibacillus albus sp. nov. is proposed. The type strain is GY 10110T (=CGMCC 1.13648T=NBRC 113502T).