Taxonomic Identification and Bioactivity Screening of the Symbiotic Bacteria Strains of Euphausia superba from Antarctic Ocean

Abstract

The marine symbiotic bacteria strains were isolated from the Antarctic krill (Euphausia superb) samples captured in Antarctica Ocean. The taxonomic identification was then performed. The screening of the bioactivity against nitric oxide (NO) release for the crude extract after the strain fermentation and cell culture extraction were finally carried out. The taxonomic identification analysis showed the strain was very close to Salegentibacter salinus ISL with the similarity value of 94.5% based on 16S rDNA gene sequencing and homology analysis. According to the analysis, this strain was identified as a new strain and nominated as Salegentibacter sp. NJ-102. The bioactivity screening analysis of the culture extract demonstrated the crude extract showed significant inhibitory bioactivity against NO release and the expression of the inducible nitric oxide synthase (iNOS) in the ECV-304 cells.