Production and optimization of polyhydroxybutyrate (PHB) from Bacillus megaterium as biodegradable plastic

Among biodegradable plastics polyhydroxy alkanate and its polymers have received more attention than other biodegradable polymers because of their complete degradability, flexibility, water resistance and also the ease of production process. Polyhydroxybutyrate is one of the types of polyhydroxy alkanates that is seen as a storage granule in many microorganisms. In this study, Bacillus megaterium was prepared from Iranian microbial collection. Glucose and yeast extract were used as the main components of the medium in seed media 9 and 2.5 g/l and in fermentation medium 30 and 7.5 g/l respectively. GC-MASS and FTIR were used to identify the PHB produced. The results showed that the highest amount of biomass (0.221 g/l) and PHB (0.080 g/l) were obtained with glucose at 37°C and shaker speed of 150 rpm for 72 h incubation. The results of GC MASS and FTIR showed the production of PHB by Bacillus under investigation. Based on the mean of data on total cell growth conditions, the rate of cell biomass and PHB production in B. megaterium were 0.0869 and 0.0171 respectively. According to the results of the experiments, temperature had the greatest effect on biomass production and PHB production. The bioplastics produced by microbes are also highly degradable in the environment, and due to their specific chemical structure, they have been widely used in various fields of the food, pharmaceutical and chemical industries and are likely to replace today's plastics in the near future.