Flavobacterium phycosphaerae sp. nov. isolated from the phycosphere of Microcystis aeruginosa

Abstract

A novel aerobic bacterial strain, designated MK012T, was isolated from the phycosphere of Microcystis aeruginosa . MK012T appears to be Gram-stain-negative, non-motile and rod-shaped and has yellow pigments. Phylogenetic analysis using 16S rRNA revealed that this bacterium was most closely related to Flavobacterium buctense T7T (=JCM 30750T; 97.5 %), Flavobacterium dankookense ARSA-19T (=KCTC 23179T; 97.5 %) and Flavobacterium macrobrachii an-8T (=DSM 22219T; 97.3 %). The genome size and genomic DNA G+C content of MK012T were estimated at 3.3 Mbp and 37.6 mol%, respectively. The average nucleotide identity (ANI), average amino acid identity (AAI) and in silico DNA–DNA hybridization (dDDH) values of MK012T and the members of the genus Flavobacterium were found to be 71.8–78.3 %, 65.1–79.6% and 19.1–21.5 %, respectively. MK012T exhibited oxidase but no catalase activity. The cells grew at 14–36 °C (optimum, 25 °C), pH 5–10 (optimum, pH 7) and 0–0.4 % (w/v) NaCl (optimum, 0 % NaCl) in R2A medium. MK012T did not produce flexirubin-type pigments. The predominant cellular fatty acids of MK012T were determined to be iso-C15 : 0, iso-C15 : 0 3-OH, iso-C17 : 0 3-OH, and summed feature 9 (10-methyl C16 : 0 and/or iso-C17 : 1ω9c); MK-6 was identified as its only respiratory quinone. Its major polar lipids were determined to be phosphatidylethanolamine, two unidentified aminolipids, and two unidentified polar lipids. The genotypic and phenotypic characteristics indicate that MK012T (=KACC 21509T=JCM 33879T) represents a novel species of the genus Flavobacterium ; therefore, the name Flavobacterium phycosphaerae sp. nov. is proposed.

Microbacterium humicola sp. nov., Microbacterium terrisoli sp. nov., Paenibacillus pedocola sp. nov., Paenibacillus silviterrae sp. nov., Flavobacterium terrisoli sp. nov., and Aquabacterium humicola sp. nov., isolated from soil

“…Furthermore, the sole menaquinone observed in strain PT-3 T was MK-6, and the only ubiquinone detected in strain RJY3 T was Q-8. The respiratory quinone systems of strains PT-3 T and RJY3 T were similar to those of other species of the genera Flavobacterium and Aquabacterium [11,77,78]. The major cellular fatty acids in strains W4 T and FW7 T were antiso-C 15 : 0 (38.7 % in W4 T and 41.2 % in FW7 T ), iso-C 16 : 0 (28.4 % in W4 T and 36.8 % in FW7 T ), and antiso-C 17 : 0 (21.7 % in W4 T and 11.5 % in FW7 T ).…”

Rhizorhabdus phycosphaerae sp. nov., isolated from the phycosphere of Microcystis aeruginosa

“…Starch hydrolysis was observed by spreading 1 % iodine solution on the plate surface after cultivation on starch hydrolysis agar [15]. Oxidase and catalase activities were determined by adding 1 % (w/v) N , N , N′ , N′ -tetramethyl- p -phenylenediamine dihydrochloride on paper discs and 10 µl droplets of 3 % (w/v) hydrogen peroxide solution on colonies, respectively [16]. Enzymatic properties and additional biochemical properties were analysed using API 20NE and API ZYM kits in accordance with the manufacturer’s instructions (bioMérieux).…”