Indian Journal of Science and Technology

Abstract

The present study focuses on the improvement of production of Poly Hydroxy Butyrate (PHB) using Bacillus megaterium MTCC 8075. The culture media and conditions were studied critically and was found that the maximum PHB production was attained in the presence of glucose as carbon source at 6% concentration with a yield of 55.0 mg/g cell weight and peptone as nitrogen source with a yield of 17.2mg/g cell weight. The optimum pH was found to be 7(22.8mg/g) and it was also investigated that PHB production was maximum corresponding to a temperature of 35°C (35.46mg/g) and at an incubation time of 72 hours (52.2mg/g). PHB was qualitatively analysed using Sudan Black staining method, extracted using sodium hypochlorite, and quantified using crotonic acid assay in UV spectrophotometer at a wavelength of 235nm. PHB production was carried out in various selected effluents like corn stalk waste and petroleum refinery effluent and corn corb yielded the maximum PHB production of 3.1mg/L. The produced PHB was confirmed using Fourier Transform Infrared (FTIR) analysis and NMR spectroscopic studies. PHB production was further improved using two-stage batch culture studies in which PHB production was compared in various nutrient limited conditions of nitrogen and phosphorous. The thermal properties of PHB was studied using Differential Scanning Calorimetry(DSC) and Thermogravimetric Analysis (TGA).
Keywords: Sudan Black, Bacillus megaterium, Crotonic Acid, Sodium Hypochlorite, FTIR, NMR, TGA, DSC