RESEARCH HIGHLIGHTS - A novel alginate-degrading bacterium, Saccharobesus litoralis: a novel genus of the family Alteromonadaceae.

by Rosyada Amran Amrina , Go Furusawa , Nyok-Sean Lau

Earth may contain 10¹¹ to 10¹² species of microbes, and 99.999 percent of them have yet to be discovered and identified. Of course, many bacterial species in the marine ecosystem are yet identified. In 2016, we isolated an alginate-degrading bacterium, CCB-QB4^T, from a coastal area of Penang, Malaysia. Ms. Rosyada Amrina and Dr. Nyok-Sean Lau, under the supervision of Dr. Go Furusawa, identified the strain using phenotypic, chemotaxonomic, and phylogenetic approaches.

Phylogenetic analysis based on the 16S rRNA gene sequence of strain CCB-QB4^T showed 94.07, 92.69, 91.52, and 90.90 % sequence similarity to Algibacillus agarilyticus RQJ05^T, Catenovulum maritimum Q1^T, C. agarivorans YM01^T, and C. sediminis D2^T, respectively. The low sequence similarity indicated that CCB-QB4^T does not belong to these genera. Average nucleotide identity (ANI), the average amino acid identity (AAI), and the digital DNA–DNA hybridization (dDDH) values of CCB-QB4^T against four test strains are well below the species threshold values, indicating that CCB-QB4^T is classified in a novel genus. Interestingly, although A. agarilyticus RQJ05^T, which is the closest species of CCB-QB4^T, did not require any carbon sources for its cell growth, the addition of carbon sources was mandatory for the cell growth of CCB-QB4^T. The major cellular fatty acid composition of CCB-QB4T was not similar to that of A. agarilyticus RQJ05^T. These results demonstrated that strain CCB-QB4^T represents a novel species in a new genus of the family Alteromonadaceae, for which the name Saccharobesus litoralis gen. nov., sp. nov. is proposed.




Link:   DOI: 10.1099/ijsem.0.005087

CCB Ref.:  2022_RH_gf_02
Date:  18/10/2022