Tabrizicola algicola sp. nov. isolated from culture of microalga Ettlia sp.

A novel Gram-stain-negative, aerobic, non-spore-forming, non-motile, and rod-shaped bacterium, strain ETT8T was isolated from a chemostat culture of microalga Ettlia sp. YC001. Optimal growth was with 0-2% NaCl and at 25-37 °C on R2A medium. Phylogenetic analysis based on the 16S rRNA gene and genome sequence showed that strain ETT8T belongs to the genus Tabrizicola, with the close neighbours being T. sediminis DRYC-M-16T (98.1 %), T. alkalilacus DJCT (97.6 %), T. fusiformis SY72T (96.9 %), T. piscis K13M18T (96.8 %), and T. aquatica RCRI19T (96.5 %). The genomic comparison of strain ETT8T with type species in the genus Tabrizicola was analysed using the genome-to-genome distance calculator (GGDC), average nucleotide identity (ANI), and average amino acid identity (AAI) (values indicated ≤17.7, ≤75.4 and ≤71.9 %, respectively). The genomic DNA G+C content of strain ETT8T was 64.4 %, plus C18 : 1 ω6c and C18 : 0-iso were the major fatty acids and Q-10 the major respiratory quinone. Strain ETT8T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine aminolipid, and four unidentified lipids as the major polar lipids. Based on the chemotaxonomic, genotypic, and phenotype results, strain ETT8T was recognized as a novel species of the genus Tabrizicola for which the name Tabrizicola algicola sp. nov. is proposed. The type strain is ETT8T (=KCTC 72206T=JCM 31893T=MCC 4339T).

Desertomycin G, a New Antibiotic with Activity against Mycobacterium tuberculosis and Human Breast Tumor Cell Lines Produced by Streptomyces althioticus MSM3, Isolated from the Cantabrian Sea Intertidal Macroalgae Ulva sp.

The isolation and structural elucidation of a structurally new desertomycin, designated as desertomycin G (1), with strong antibiotic activity against several clinically relevant antibiotic resistant pathogens are described herein. This new natural product was obtained from cultures of the marine actinomycete Streptomyces althioticus MSM3, isolated from samples of the intertidal seaweed Ulva sp. collected in the Cantabrian Sea (Northeast Atlantic Ocean). Particularly interesting is its strong antibiotic activity against Mycobacterium tuberculosis clinical isolates, resistant to antibiotics in clinical use. To the best of our knowledge, this is the first report on a member of the desertomycin family displaying such activity. Additionally, desertomycin G shows strong antibiotic activities against other relevant Gram-positive clinical pathogens such as Corynebacterium urealyticum, Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Enterococcus faecium, Enterococcus faecalis, and Clostridium perfringens. Desertomycin G also displays moderate antibiotic activity against relevant Gram-negative clinical pathogens such as Bacteroides fragilis, Haemophilus influenzae and Neisseria meningitidis. In addition, the compound affects viability of tumor cell lines, such as human breast adenocarcinoma (MCF-7) and colon carcinoma (DLD-1), but not normal mammary fibroblasts.

Gelatiniphilus marinus gen. nov., sp. nov., a bacterium from the culture broth of a microalga, Picochlorum sp. 122, and emended description of the genus Hwangdonia.

A Gram-stain-negative, non-motile, non-spore-forming, rod-shaped bacterium, designated strain GYP-24T, was isolated from the culture broth of a marine microalga, Picochlorum sp. 122. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain GYP-24T forms a robust cluster with H.wangdoniaseohaensis KCTC 32177T (95.8 % sequence similarity) in the family Flavobacteriaceae. Growth of strain GYP-24T was observed at 15, 22, 28, 30, 33 and 37 °C (optimal 30-33 °C), pH 6.0-10.0 (optimal pH 7.0-8.0) and in the presence of 0.5-4 % (w/v) NaCl (optimal 2-3 %). The only menaquinone of strain GYP-24T was MK-6, and the G+C content of the genomic DNA was 36.9 mol%. The major fatty acid profile comprised iso-C17 : 0 3-OH, summed feature 3 (C16 : 1 ω7c/ω6c), iso-C15 : 1 G and iso-C15 : 0. The major polar lipids of strain GYP-24T were phosphatidylethanolamine, one unidentified phospholipid, three unidentified aminolipids and three unidentified lipids. Comprehensive analyses based on polyphasic characterization of GYP-24T indicated that it represents a novel species of a new genus, for which the name Gelatiniphilus marinus gen. nov., sp. nov. is proposed. The type strain is GYP-24T (=KCTC 42903T=MCCC 1K01730T). An emended description of the genus Hwangdonia is also given.

Permianibacter aggregans gen. nov., sp. nov., a bacterium of the family Pseudomonadaceae capable of aggregating potential biofuel-producing microalgae.

A novel bacterial strain, capable of aggregating potential biofuel-producing microalgae, was isolated from the phycosphere of an algal culture and designated HW001(T). The novel bacterial strain was identified on the basis of its phylogenetic, genotypic, chemotaxonomic and phenotypic characteristics in this study. Cells were aerobic, Gram-negative rods. 16S rRNA gene-based phylogenetic analysis revealed that strain HW001(T) is affiliated with the family Pseudomonadaceae in the phylum Proteobacteria, but forms a distinct clade within this family. The DNA G+C content of strain HW001(T) was 55.4 mol%. The predominant cellular fatty acids were iso-C15:0, summed feature 9 (iso-C17:1ω9c), C16:0 and summed feature 3 (C16:1ω7c/C16:1ω6c). Q-8 was the main respiratory quinone. The polar lipid profile contained phosphatidylethanolamine, an unidentified aminophospholipid and some unidentified lipids. Based on the extensive polyphasic analysis, strain HW001(T) represents a novel species of a new genus in the family Pseudomonadaceae, for which the name Permianibacter aggregans gen. nov., sp. nov., is proposed. The type strain of the type species is HW001(T) ( = CICC 10856(T) = KCTC 32485(T)).