Bioconversion of sugarcane molasses to poly(3-hydroxybutyrate-co-3- hydroxyvalerate) by endophytic Bacillus cereus RCL 02

ABSTRACT

Sugarcane molasses, the by-product of sugar industry are rich in nutrients, growth factors and minerals and areefficiently utilized by the microorganisms for growth and production of primary as well as secondary metabolitesof commercial importance. In this communication, we report the utilization of sugarcane molasses as the solesource of carbon for the production of copolymers of polyhydroxyalkanoates (PHAs) with improved materialproperties. The endophytic bacterium Bacillus cereus RCL 02 (MCC 3436) produced 7.8 g/L of PHA whengrown in MS medium with 4% (w/v) sugarcane molasses under batch cultivation. Proton nuclear magneticresonance (1H NMR) analysis revealed that the copolymer so produced contain 12.4 mol% 3-hydroxyvalerate(3HV) along with 87.6 mol% 3-hydroxybutyrate (3HB). The copolyester, P(3HB-co-12.4 mol%-3HV)has been isolated and purified following standard solvent extraction method and partially characterized byFourier-transform infrared (FTIR), X-ray diffraction (XRD), thermogravimetric (TG) and differential scanningcalorimetric (DSC) analysis. The material and thermal properties of the copolyester so produced indicated itspotential for industrial application.