Efficient bioconversion of sugarcane bagasse into polyhydroxybutyrate (PHB) by Lysinibacillus sp. and its characterization

Rijuta GaneshSaratale^a, Si Kyung Cho^b, Ganesh Dattatraya Saratale^c, Gajanan S. Ghodake^b, Ram Naresh Bharagava^d, Dong Su Kim^a, Supriya Nair^f, Han Seung Shin^c

Research Institute of Biotechnology and Medical Converged Science, Dongguk University-Seoul, Ilsandong-gu, Goyang-si, Gyeonggido 10326, Republic of Korea.

Abstract

In this study, Lysinibacillus sp. RGS was evaluated to synthesize polyhydroxybutyrate (PHB) from a broad range of pure carbon sources and residual sugars of chemically pretreated sugarcane bagasse (SCB) hydrolysates. Effects of supplementation of nutrients and various experimental variables to enhance PHB accumulation were investigated. Results of optimized parameters were identified as 48 h, 37 °C, pH 7; inoculums concentration (2.5% v/v) and shaking condition (100 rpm). Growth kinetics and bioprocess parameters of Lysinibacillus sp. using SCB hydrolysates with corn steep liquor (2%) accounted for the maximum cell growth (8.65 g/L) and PHA accumulation (61.5%) with PHB titer of (5.31 g/L) under optimal conditions. The produced biopolymer was studied by Fourier Transform Infrared (FTIR) spectroscopy and the results revealed the obtained to be PHB. Thus Lysinibaciluus sp. exhibits high potential in industrial scale manufacture of PHB using SCB as an inexpensive substrate.

Keywords: Lysinibacillus sp. RGS, Sugarcane bagasse, Peracetic acid pretreatment, Poly(3-hydroxybutyrate), Saccharification yield, Corn steep liquor