Isolation of Spirosoma foliorum sp. nov. from the fallen leaf of Acer palmatum by a novel cultivation technique.

In the effort of isolating novel microbial species, the strain PL0132T was isolated from a fallen leaf under fresh water at a stream, which glided when grown on a tap water medium (without nutrients). The strain was determined to be Gram-negative, strictly aerobic, and rod-shaped, which grew optimally at 25 °C, pH 6-7, and the strain tolerates 1% (w/v) NaCl concentration. The complete genome of strain PL0132T comprises one contig with a sequencing depth of 76×, consisting of 8,853,064 base pairs and the genomic DNA G + C content was 46.7% (genome). 16S rRNA gene sequence analysis revealed that strain PL0132T represents a member of the phylum Bacteroidetes and is affiliated with the genus Spirosoma. Based on genomic, phenotypic, and chemotaxonomic characteristics, the strain PL0132T represents a novel species of the genus Spirosoma, for which the name Spirosoma foliorum sp. nov. is proposed (= KCTC 72228 T = InaCC B1447T).

Three marine species of the genus Fulvivirga, rich sources of carbohydrate-active enzymes degrading alginate, chitin, laminarin, starch, and xylan.

Bacteroidota is a group of marine polysaccharide degraders, which play a crucial role in the carbon cycle in the marine ecosystems. In this study, three novel gliding strains, designated as SS9-22T, W9P-11T, and SW1-E11T, isolated from algae and decaying wood were proposed to represent three novel species of the genus Fulvivirga. We identified a large number of genes encoding for carbohydrate-active enzymes, which potentially participate in polysaccharide degradation, based on whole genome sequencing. The 16S rRNA sequence similarities among them were 94.4-97.2%, and against existing species in the genus Fulvivirga 93.1-99.8%. The complete genomes of strains SS9-22T, W9P-11T, and SW1-E11T comprised one circular chromosome with size of 6.98, 6.52, and 6.39 Mb, respectively; the GC contents were 41.9%, 39.0%, and 38.1%, respectively. The average nucleotide identity and the digital DNA-DNA hybridization values with members in the genus Fulvivirga including the isolates were in a range of 68.9-85.4% and 17.1-29.7%, respectively, which are low for the proposal of novel species. Genomic mining in three genomes identified hundreds of carbohydrate-active enzymes (CAZymes) covering up to 93 CAZyme families and 58-70 CAZyme gene clusters, exceeding the numbers of genes present in the other species of the genus Fulvivirga. Polysaccharides of alginate, chitin, laminarin, starch, and xylan were degraded in vitro, highlighting that the three strains are rich sources of CAZymes of polysaccharide degraders for biotechnological applications. The phenotypic, biochemical, chemotaxonomic, and genomic characteristics supported the proposal of three novel species in the genus Fulvivirga, for which the names Fulvivirga ulvae sp. nov. (SS9-22T = KCTC 82072T = GDMCC 1.2804T), Fulvivirga ligni sp. nov. (W9P-11T = KCTC 72992T = GDMCC 1.2803T), and Fulvivirga maritima sp. nov. (SW1-E11T = KCTC 72832T = GDMCC 1.2802T) are proposed.

Vibrio ostreae sp. nov., a novel gut bacterium isolated from a Yellow Sea oyster.

A Gram-stain-negative, oxidase- and catalase-positive, facultative anaerobic motile bacterium, designated strain OG9-811T, was isolated from the gut of an oyster collected in the Yellow Sea, Republic of Korea. The strain grew at 10-37 °C, pH 6.0-9.0 and with 0.5-10% (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain OG9-811T affiliated with the genus Vibrio, with the highest sequence similarity of 98.2% to Vibrio coralliilyticus ATCC BAA-450T followed by Vibrio variabilis R-40492T (98.0 %), Vibrio hepatarius LMG 20362T (97.7 %) and Vibrio neptunius LMG 20536T (97.6 %); other relatives were Vibrio tritonius JCM 16456T (97.4 %), Vibrio fluvialis NBRC 103150T (97.0 %) and Vibrio furnissii CIP 102972T (97.0 %). The complete genome of strain OG9-811T comprised two chromosomes of a total 4 807 684 bp and the G+C content was 50.2 %. Results of analysis based on the whole genome sequence showed the distinctiveness of strain OG9-811T. The average nucleotide identity (ANI) values between strain OG9-811T and the closest strains V. coralliilyticus ATCC BAA-450T, V. variabilis R-40492T, V. hepatarius LMG 20362T, V. neptunius KCTC 12702T , V. tritonius JCM 16456T, V. fluvialis ATCC 33809T and V. furnissi CIP 102972T were 73.0, 72.6, 73.3, 73.0, 72.7, 78.5 and 77.8 %, respectively, while the digital DNA-DNA hybridization values between strain OG9-811T and the above closely related strains were 20.8, 21.2, 20.8, 21.7, 20.7, 23.2 and 22.4 %, respectively. The major fatty acids of strain OG9-811T were summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), summed feature 8 (C18:1 ω6c and/or C18:1 ω7c) and C16:0. The polar lipids contained phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Strain OG9-811T contained Q-8 as a quinone. On the basis of polyphasic taxonomic characteristics, strain OG9-811T is considered to represent a novel species, for which the name Vibrio ostreae sp. nov. is proposed. The type strain is OG9-811T (=KCTC 72623T=GDMCC 1.2610T).

Flavobacterium litorale sp. nov., isolated from red alga.

A Gram-stain-negative and rod-shaped bacterial strain (WSW3-B6T) was isolated from red alga collected from the West Sea, Republic of Korea. Cells of strain WSW3-B6T were non-motile, aerobic and produced slightly yellow and mucoid colonies on marine agar. The strain grew optimally at 23-30 °C, with 0.5-4 % NaCl (w/v) and at pH 6.5-8.5. A phylogenetic analysis of the 16S rRNA gene revealed that strain WSW3-B6T belongs to the genus Flavobacterium within the family Flavobacteriaceae, having the highest sequence similarity to Flavobacterium arcticum SM1502T (96.7%), followed by Flavobacterium salilacus subsp. altitudinum LaA7.5T (96.2%) and Flavobacterium salilacus subsp. salilacus SaA2.12T (96.2%). The complete sequence of a circular chromosome of strain WSW3-B6T determined by combination of Oxford Nanopore and Illumina platforms comprised a total 2 725 095 bp with G+C content of 37.1 mol%. A comparative analysis based on the whole genome also showed the distinctiveness of strain WSW3-B6T. The average nucleotide identity (ANI) values between strain WSW3-B6T and the closest strains F. arcticum SM1502T, F. salilacus subsp. altitudinum LaA7.5T and F. salilacus subsp. salilacus SaA2.12T were 78.3, 77.8 and 77.7 %, respectively, while the digital DNA-DNA hybridization (dDDH) values between strain WSW3-B6T and the above closely related strains were 21.0, 20.4 and 20.3 %, respectively. Both the ANI and dDDH values supported the creation of a new species in the genus Flavobacterium. The major fatty acids (>10 %) were iso-C15 : 0 (19.3 %), C16 : 0 (14.0 %), iso-C17 : 0 3-OH (13.1 %) and C18 : 0 (10.7 %). The polar lipids of strain WSW3-B6T included phosphatidylethanolamine, three unidentified aminolipids and three unidentified lipids. Moreover, MK-6 was the only respiratory quinone. A comparison of the phylogenetic distinctiveness and the unique phenotypic and chemotaxonomic characteristics among strain WSW3-B6T and closely related type strains supported that strain WSW3-B6T (=KCTC 82708T=GDMCC 1.2627T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium litorale sp. nov. is proposed.

Cellulosimicrobium protaetiae sp. nov., isolated from the gut of the larva of Protaetia brevitarsis seulensis.

A Gram-stain-positive, non-spore-forming, yellow-pigmented, non-motile, non-flagellated, facultative anaerobic and rod-shaped bacterial strain, designated BI34T, was isolated from the gut of the larva of Protaetia brevitarsis seulensis. Strain BI34T grew at 15-40 °C (optimum, 37 °C), at pH 6.5-9.0 (optimum, pH 7.5) and in the presence of 0-7 % (w/v) NaCl (optimum, 2 %). Based on the results of 16S rRNA gene sequence analysis, strain BI34T belonged to the phylum Actinobacteria and was closely related to Cellulosimicrobium funkei NBRC 104118T (99.3 %), Cellulosimicrobium cellulans NBRC 15516T (99.1 %), Cellulosimicrobium composti BIT-GX5T (99.0 %), Cellulosimicrobium fucosivorans SE3T (99.0 %), Cellulosimicrobium marinum NBRC 110994T (98.4 %) and Cellulosimicrobium terreum DS-61T (97.0 %). The genome to genome relatedness of the average nucleotide identity (ANI) and the digital DNA-DNA hybridization (dDDH) values calculated by the Genome-to-Genome Distance Calculator between strain BI34T and its related species mentioned above were lower than the threshold of 95 and 70 % for speciation, respectively. The predominant menaquinone of strain BI34T contained MK-9(H4), and the major fatty acids were anteiso-C15 : 0, C16 : 0 and anteiso-C17 : 0. Strain BI34T had diphosphatidylglycerol and phosphatidylglycerol as major polar lipids. The whole-cell sugars were galactose, glucose and ribose, and the cell-wall peptidoglycan contained lysine, alanine, aspartic acid and glutamic acid. The DNA G+C content of strain BI34T was 73.8 mol%. The difference in physiological and biochemical characteristics and the below-threshold values of genome-to-genome relatedness indicate that strain BI34T represents a novel species in the genus Cellulosimicrobium, for which the name Cellulosimicrobium protaetiae sp. nov. is proposed. The type strain is BI34T (=KCTC 49302T=NBRC 114073T).

Complete genome sequence of Bacillus ciccensis 5L6T, a new species isolated from maize (Zea mays L.) seeds with anti-fungal activity.

Maize is a crop grown worldwide. Bacillus ciccensis 5L6T was isolated from maize (Zea mays L., Jingke968) seeds and was a new species of Bacillus with potential anti-fungal activity. The complete genome of 5L6T was sequenced and assembled with a length of 5,207,802 bp and a GC content of 37.42%. The proteins responsible for anti-fungal activity and the potential beneficial interaction with maize of 5L6Twere annotated and reported here. The complete genome sequence of the new species B. ciccensis 5L6T will promote its biological application.