Bioplastic (Polyhydroxyalkanoate) producing Indigenous Bacteria from Agricultural Soil Samples

Polyhydroxyalkanoate (PHA) is the naturally occurring biopolymer produced by the microorganisms. It is biodegradable and having physicochemical properties similar to conventional synthetic plastics and it can be used as an alternative to plastics. PHA is produced by microorganisms including bacteria, archaea and fungi. It gets accumulated inside the microorganisms as crystal in the presence of excess source of carbon, nitrogen, sulphur, oxygen and limited source of other nutrients. In this study PHA producing strain was isolated from agricultural soil sample. All the isolates obtained were screened for PHA production by using Nile red and Sudan black dyes. The potential isolate was characterized by biochemical tests and identified using 16S rRNA sequencing. The isolate showed sequence similarity with Priestia aryabhattai B8W22 and was designated as Priestia aryabhattai VITJK01. For PHA production, seed culture was prepared and inoculated in mineral salt medium containing glucose as a carbon source. PHA was extracted from cell dry weight biomass using methanolysis. It produced polyhydroxybutyrate (PHB) compounds including dodecane, penta decanoic acid, octadecanoic acid and heptadecanoic acid identified by Gas Chromatography Mass Spectrometry. Based on the results, it can be concluded that Priestia aryabhattai VITJK01 is a potential source for PHA/PHB production.