Isolation and identification of some cultivated bacteria from the sea area of Rizhao for screening of agarase-producing bacteria

Abstract:

Marine bacteria are the major members of marine life. Compared with those living on the land, marine bacteria exhibit high diversity in species, genes and ecological functions, valuable for both fundamental studies and biotechnological applications.[Objective] Isolation and identification of some culturable bacteria from the sea area of Rizhao for screening of agarase producing strains.[Methods] A total of 73 strains were isolated and their 16S rRNA genes were sequenced. Agarsae activity of agar-digesting strains was determined.[Results] These isolates belong to 34 genera, 13 family and 4 phyla, showing rich species diversity. Furthermore, 16S rRNA gene sequence analysis also showed that among these 73 strains, 18 strains potentially represented novel species. Our results also showed that 5 strains were positive for agarase activity and the highest agarase activity of these strains was determined to be 2.17±0.04 U/mL.[Conclusion] This study widens our understanding for the diversity of marine bacteria in species and agarase activity.

Key words:culturable bacteria;bacterial diversity;novel species;agarase activity