Media engineering for production of poly-beta-hydroxybutyrate by Bacillus firmus NII 0830

Abstract

This study evaluates biodiesel industry generated crude glycerol as sole carbon source for the production of poly-beta-hydroxybutyrate (PHB) using Bacillus firm us NII 0830. Pretreatment of crude glycerol from biodiesel industry was tried using strong acids. Biomass yield and PHB accumulation by B. firm us Nil 0830 in submerged fermentation was compared using crude as well as pretreated glycerol as sole carbon source. It was observed that crude glycerol from biodiesel industry, without any pretreatment, can be used for PHB production. The organism when grown in mineral salt media containing crude glycerol as carbon source gave a maximum yield of biomass (3 g/l) and PHB (53% of cell dry wt). Response surface methodology (RSM) showed that presence of nitrogen and phosphate in fermentation media favored biomass production but reduced PHB production. Optimized crude glycerol media for maximum PHB accumulation contains ammonium sulphate (4 g/l) and K(2)HPO(4) (0.8 g/l).