Isolation and characterization of polyhydroxyalkanoates accumulating <i>Vibrio </i>sp. strain BTTC26 from marine sediments and its production kinetics

Abstract

Sediment samples collected from various marine environments were screened for polyhydroxyalkanoates (PHAs) accumulating <i>Vibrio </i>sp. using Nile Blue A staining plate assay and 92 of the 148 <i>Vibrio </i>sp. showed positive result. High incidence (62%) of PHA accumulating vibrios were observed in this study. <i>Vibrio </i>sp. strain BTTC26 showing maximum PHA accumulation during preliminary screening by plate assay methods and spectrophotometric analysis was selected for further studies. Based on the phenotypic characterization studies and partial 16S rDNA sequence analysis, the strain BTTC26 was identified as <i>V.azureus </i>(99% identity). The strain BTTC26 showed multiple hydrolytic enzymes production like amylase, lipase, caseinase, gelatinase and DNase. In addition, it has the multiple antibiotic resistance (MAR) index of 0.3. The intracellular accumulation of PHAs by BTTC26 was optimized at pH - 7, with glucose as carbon source, 36h incubation time , 3% initial inoculum concentration, 37^oC incubation temperature and 10% NaCl concentration. FTIR analysis showed that polyhydroxybutyrates (PHB), the smallest reported PHAs was accumulated by strain BTTC26, having wide range of industrial and medical applications. In addition, several strains of fast-growing <i>Vibrio </i>sp. accumulating intracellular PHAs were also isolated during this study.