Efficient polyhydroxybutyrate production from Bacillus thuringiensis using sugarcane juice substrate

Abstract

The present study focused on the screening and optimization of biopolymer polyhydroxybutyrate (PHB) production byBacillusspp. using cost-effective substrates. Among 602 localBacillusisolates,Bacillus thuringiensisB417-5 produced the highest amountof PHB (2.278 g/L, 60.07% of dry cell weight, DCW).1 H NMR and FTIR analyses of the extracted polymer revealed the characteristicpeaks of PHB. The optimization results showed that the highest PHB accumulation (2.768 g/L, 72.08% of DCW) was achieved whenculturingB. thuringiensisB417-5 in a nitrogen-deficient medium containing 1% total sugar from sugarcane juice and 0.5% yeast extract,with a pH of 7.0 and an incubation temperature of 37 °C for 48 h.B. thuringiensisB417-5 can thus be considered a good candidate forlarge-scale production of PHB. We are reporting for the first time that sugarcane juice is a promising carbon source for economical PHBproduction byB. thuringiensis.