Production and Optimization of Polyhydroxyalkaonoate Obtained from Bacillus megaterium JHA

Introduction: The last four decades have recognized the critical environmental issues pertaining to the use of non-degradable synthetic plastics. Currently, the synthesis of biodegradable polymers, like polyhydroxyalkaonoates (PHA) has been gaining considerable interest as a sustainable approach to overcome these issues. The current study was carried out with an objective to optimize the PHA production from Bacillus megaterium JHA.Materials and Methods: Various nutritional and physico-chemical parameters were optimized using the ‘one factor at a time’ approach. The findings were analysed statistically by one-way ANNOVA and linear regression using the open-source R software.Results: The optimum physico-chemical parameters for maximum PHA production were attained when ۵% inoculum size of B. megaterium JHA was added to the JHA medium (pH ۸) and incubated at ۲۸ °C for ۹۶ h under shaker conditions (۱۲۰ rpm). The nutritional parameters were further optimized by addition of ۰.۶ g% K۲HPO۴, ۰.۴ g% KH۲PO۴, ۲۱ g% glucose, ۱۲.۵ mM microcosmic salt, ۰.۰۴ g% KNO۳, ۱ mM MgSO۴, and ۲ ml trace elements to the JHA medium. The C:N and C:P ratio was adjusted to ۷۰:۱ and ۲۰:۱ respectively. The growth of bacteria under these optimized parameters allowed ۱۳.۷۱ g/L accumulation of PHA leading to a yield of ۵۴.۵۱%. This resulted in ۶۶.۸۸% increase in yield as compared to the original medium. The scale-up study using a ۲ L fermenter further increased PHA accumulation by ۴.۳۹% under optimized conditions.Conclusions: The above results clearly indicate that B. megaterium JHA is a promising isolate that can be exploited for the industrial production of PHA.

Keywords:

Biopolymer , Fermenter , JHA Medium , Optimize , sustainable