Biochemical and molecular characterization of temperature-adapted agarase from sea urchin associated Vibrio sonorensis NIOT_SU2 from Andaman Island

Abstract

A total of 143 isolates of aerobic, heterotrophic bacteria were isolated from the gut, peristomial membrane, spine, tooth and coelomic fluid of sea urchin, Diadema savignyi and Echinometra oblonga from the coastal area of Marina Park, Port Blair, South Andaman. The bacterial strain with agarolytic potential has been identified as Vibrio sonorensis NIOT_SU2 C 9(b). Agarase-NIOT_SU2 C 9(b) from the culture medium was isolated and purified with 47.78-fold from the culture fluid by a combination of ammonium sulphate precipitation, dialysis and successive purification by DEAE cellulose column chromatography. Purified protein migrated as a single band (46 kDa) on sodium dodecyl sulphate-polyacrylamide gels. The optimum pH and temperature of the agarase were 7.6 and 30–35 °C, respectively. Agarase enzyme maintained as much as 85% of the maximum activities at wide range of temperatures and this enzyme did not decompose sodium alginate. This work is the first evidence of cold and temperature-adapted agarase from sea urchin associated bacteria and the results of this study authenticated the potential for the agarase-NIOT_SU2 C 9(b) as a catalyst in medicine, food, cosmetic industries and practical application in gene technology.