Potential of PHA Accumulation in Escherichia Coli, Bacillus Subtilis and Pseudomonas Aeruginosa Cultured on Agro-Industrial Byproducts

Abstract

Polyhydroxyalkanoates (PHAs) are type of natural polymers which are synthesized by different microorganisms to increase their survival rate during environmental change or stress conditions. The biodegradable polymers are an alternative solution to non-renewable petroleum derived plastics. The aim of this study is to produce PHAs by Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa using agro and industrial waste such as wheat bran and cane molasses. In this work, the effect of different media on each bacterium was studied. The optimum environmental condition that supported the PHA production by the three strains was inoculum concentration of 8%, pH 7.0 and temperature of 30°C. The medium was fermented for five days in orbital shaker. Each day samples were collected and analyzed. Dry cell weight and PHA accumulated was observed for each of the bacteria. On the basis of data obtained in the present work, compared to B. subtilis and E. coli, P. aeruginosa was capable to accumulate 70.27% of PHA by using Cane molasses and Wheat bran as substrate. This could be employed for industrial application after subsequent optimization of the conditions of PHA synthesis. The present study explored the potential of Pseudomonas aeruginosa to produce cost-effective PHA as an alternative to petroleum based plastics.