Polyphasic identification of amylolytic bacteria producing bioplastic Poly-β-hydroxybutyrate (PHB)

Abstract

The final goal of this study is to make a modern systematic-based inventory of amylolytic bacterial isolates producing of bioplastic Poly-β-hydroxybutyrate (PHB) from sago starch substrate. The identity of three local bacterial isolates was examined in this study, using a polyphasic approach. A data set based on phenotypic characteristics, namely morphological, physiological, biochemical and chemical character, namely whole cells protein profiles using SDS-PAGE method, together with phylogenetic studies based on 16S rRNA sequences was used to identified by polyphasic approach. Phenotypic characteristics of 3 local bacterial isolates and 4 reference strains to members of genus Bacillus was analyzed by numerical analysis using MVSP 3,1 program to determine the value of similarity. Based on the preliminary characterization of the profile matching method showed that the three isolates of bacteria producing PHB namely PSA10, PPK5 and PPK6 are members of the genus Bacillus. The results of numerical analysis based on phenotypic characteristic and chemical character of the three bacterial isolates producing PHB with reference strains showed that the PSA10 isolate bacterial identical with Bacillus megaterium, PPK5 isolate identical with Bacillus subtilis and PPK6 isolate identical with Bacillus cereus, and these results also support by the molecular phylogenetic analysis. Therefore, the polyphasic taxonomy is an effective approach to uncover the identity of the novel bacterial isolates.