Optimization of PHB production utilizing agro-waste as a sustainable substrate by the native isolate Bacillus cereus

Microbial synthesis of polyhydroxyalkanoates (PHA), eco-friendly biopolymers is gaining more attention towards restricting environmental pollution by substituting the conventional non-biodegradable petroleum-based plastics. The current study is aimed to economize the polyhydroxybutyrate (PHB) production by optimizing the production media using sago waste as the cheapest carbon source. Bacillus cereus is a native isolate obtained from the soil where sago waste is disposed in and around Salem District, Tamil Nadu, India. PHB production media was optimized by Placket Burman design and Box Behnken design (pH: 7.07, temperature: 36.36 degrees C and sago waste: 19.7g/l)) and maximum OD values of 2.006 were observed in shake flask culture. The dry weight of PHB extracted under optimized conditions was measured by the chloroform extraction method and it was found to be 5.2g/l. In addition, Fourier-transform infrared spectroscopy (FTIR), Thin-layer chromatography (TLC) and Gas Chromatography-Mass Spectrometry (GC-MS) analysis revealed the characteristic features of the PHB polymer. Thus, this study concludes that the utilization of sago waste for the synthesis of valueadded products like PHB will not only help in reducing the cost of the PHB production process but also will assist to manage the problems associated with solid waste disposal.