Production, process optimization and molecular characterization of polyhydroxyalkanoate (PHA) by CO2 sequestering B. cereus SS105

• Published in: Bioresource technology 2018-04, Vol.254, p.75-82
• Main Authors: Maheshwari, Neha, Kumar, Madan, Thakur, Indu Shekhar, Srivastava, Shaili
• Format: Article
• Language: English
• Subjects: B. cereus SS105; CO2 sequestration; PHA biosynthesis genes; Polyhydroxyalkanoate (PHA); Response Surface Methodology (RSM)
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2018.01.002

[Display omitted] •CO2 sequestering B. cereus SS105 was screened for PHA production using Nile red.•PHA characterization by GC–MS, FTIR and NMR analysis.•Molecular analysis of PHA production was confirmed by PHA biosynthesis gene.•PHA production was optimized with cheap carbon sources by RSM using BBD. Carbon dioxide sequestering bacterial strains were previously isolated from free air CO2 enriched (FACE) soil. In the present study, these strains were screened for PHA accumulation and Bacillus cereus SS105 was found to be the most prominent PHA accumulating strain on sodium bicarbonate and molasses as carbon source. This strain was further characterized by Spectrofluorometric method and Confocal microscopy after staining with Nile red. PHA granules in inclusion bodies were visualized by Transmission Electron Microscopy. The PHA and its monomer composition were characterized by GC–MS followed by FTIR and NMR. The genetic basis of PHA production was confirmed by the amplification, cloning and analysis of PHA biosynthesis genes phaR, phaB and phaC from B. cereus with the degenerate primers. The PHA production was further optimized by Response Surface Methodology and the percent increase observed after optimization was 55.16% (w/v).