Algibacillus agarilyticus gen. nov., sp. nov., isolated from the surface of the red algae Gelidium amansii

Abstract

A novel Gram-stain-negative, strictly aerobic, coccoid and agar-hydrolysing bacterium, designated RQJ05T, was isolated from the marine red algae Gelidium amansii collected from the coastal area of Rizhao, PR China. Cells of strain RQJ05T were approximately 0.8–1.0×1.3–3.0 µm in size and motile by means of a polar flagellum. Growth occurred at 4–33 °C (optimum, 25–30 °C), pH 7.0–8.5 (optimum, pH 7.5–8.0) and in the presence of 1.0–7.0 % (w/v) NaCl (optimum, 2.0–3.0 %). Strain RQJ05T showed oxidase-positive and catalase-negative activities. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain RQJ05T formed a phylogenetic lineage with members of the family Alteromonadaceae and exhibited 16S rRNA gene sequence similarities of 92.6, 91.3, 90.2 and 90.1 % to Catenovulum maritimum Q1T, Catenovulum agarivorans YM01T, Paraphotobacterium marinum NSCS20N07DT and Algicola sagamiensis B-10-31T, respectively. The major cellular fatty acids of strain RQJ05T were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C16 : 0 and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The major polar lipids of strain RQJ05T were phosphatidylethanolamine, phosphatidylglycerol and two aminophospholipids. Strain RQJ05T contained Q-8 as the major respiratory quinone. The genomic DNA G+C content was 39.0 mol%. On the basis of genotypic, phenotypic and phylogenetic evidence, strain RQJ05T is presented as a representative of a novel species in a new genus, for which the name Algibacillus agarilyticus gen. nov., sp. nov. is proposed. The type strain is RQJ05T (=KCTC 62846T=MCCC 1H00352T).

Saccharobesus litoralis gen. nov., sp. nov., a novel alginate-degrading bacterium isolated from the surface of intertidal algal turf

“…The genome analysis revealed that the type strain A. agarilyticus RQJ05 T also possessed three β-agarases [7]. In 2019, Lau and colleagues isolated an agarolytic bacterium, a Catenovulum -like strain designated as CCB-QB4 T , from a coastal area of Penang, Malaysia (5° 19′ 30″ N; 100° 18′ 12″ E), and its complete genome was studied [8].…”

“…In contrast, A. agarilyticus RQJ05 T could grow in MB without supplementation of carbon sources [7]. All these five strains exhibited positive reactions for oxidase, alkaline phosphatase and naphthol-AS-BI-phosphohydrolase enzyme activities and were capable of starch and agar hydrolysis .…”

“…In 2021, a novel genus, Algibacillus , closely related the genus Catenovulum , was proposed by Meng et al . [7]. The genome analysis revealed that the type strain A.…”

“…agarivorans YM01 T formed long chains [1]. As for growth conditions, strain CCB-QB4 T was incapable of growing at 10 °C as compared to the other four strains [1–3, 7]. Our previous report demonstrated that strain CCB-QB4 T obligately required carbon sources, such as glucose and uronic acid-containig polysaccharides, in culture broth [9].…”

“…These results showed that the polar lipid profile of strain CCB-QB4 T was different from the four reference strains. The respiratory quinone of strain CCB-QB4 T was ubiquinone-8, the same as that of the four reference strains [3, 7].…”