Optimization and characterization of polyhydroxyalkanoate produced by Bacillus cereus

摘要

Polyhydroxyalkanoates (PHAs), biodegradable polymers, naturally produced by many micro organisms accumulate as energy reserves under abundant carbon and limiting nitrogen source. In this study, bacterial isolates from dairy effluent, oil dipped cloth, local mess food and oil wastes and few type cultures were screened for PHA production. The bacteria isolated from oil dipped cloth produced maximum concentration of PHA and this was later identified as Bacillus cereus by 16S rDNA analysis. Maximum production of PHA (270mg/L) was noticed when the bacteria was grown in Minimal medium 3 (MM3) containing 1% glucose and 0.07% ammonium hydrogen phosphate as carbon and nitrogen sources respectively. Growth and production followed a specific pattern in which PHA production started on 4^th day reaching its maximum on day 5. This was characterized by FTIR spectra that showed bands characteristic of Polyhydroxybutyrate (PHB).