Utilization of agro-industrial wastes as raw materials for the biosynthesis of polyhydroxy butyrate biopolymer from Bacillus paramycoides strain KUMBNGBT-33

Abstract

Bio plastics are natural biopolymers and synthesized by various microorganisms and these materials are non-toxic and have more advantage compared to petroleum-based conventional plastics. The present research involves the isolation, screening, characterization, optimization, and quantification of polyhydroxy butyrate (PHB) producing bacterium by using different agroindustrial waste substrate. The bacterium was isolated from dump yard of Ranganathapura, Shivamogga district, Karnataka, India. The isolated bacterium was Gram-positive, rod shaped, spore forming, and motile bacilli. The Sudan b black staining confirms the presence of PHB granules in the bacterium. Based on phenotypic and genotypic characters, the isolated bacterium was identified and confirmed as Bacillus paramycoides and its partial 16s rRNA gene sequence was deposited to GenBank, NCBI, and obtained Accession no. MW056185. The optimum conditions required for the maximum PHB production includes, nutrient broth medium, 72 h incubation time, 37°C temperature, pH = 7.0, glucose as carbon source, ammonium chloride as nitrogen source, and carbon-nitrogen in the ratio 8:1. The PHB producing bacterium was cultivated on different agroindustrial waste substrates among them maximum quantity of PHB production was found in hydrolysate of feed stock. The Bio-spectrophotometric analysis provides the ʎ-max of 319 nm, quantifies and confirms the production of PHB. All these findings reveals that the isolated B. paramycoides is an efficient PHB producer which can be exploited for the production of PHB biopolymer.