Poly-3-hydroxyalkanoates production potential of <i>Bacillus cereus</i> C113 isolated from cassava dumpsite using some carbon sources

Abstract

Poly-3-hydroxyalkanoates (PHAs) are biopolymers accumulated as intracellular energy reserves by bacteria under nutrient limiting growth conditions and suitable for plastic production. We report findings from the use of a bacterium isolated from a cassava dumpsite for PHAs production. Isolate C113 was screened for PHAs production using the viable colony and Sudan Black B staining methods and further identified by 16SrRNA sequencing. Its PHA synthase gene, PhaR, was also partially amplified and sequenced. PHAs production was achieved over 96-hour incubation, extracted by NaClO/chloroform method and analysed by FT-IR. Isolate C113 was positive for PHA production in all carbon sources and was identified as a strain of Bacillus cereus. It showed highest biomass accumulation in glucose and starch. It achieved PHAs production of 4.85 % dry cell weight (DCW) in glucose, 33.03 %DCW in glycerol and 6.05 %DCW in sugarcane molasses at 24 hours while 10.58 %DCW was produced in starch at 96 hours. FT-IR spectra showed peaks corresponding to P3HB and P3HB3HV and reveal conformational changes of mcl-PHA and scl-PHA in crystalline and amorphous phases. The 16SrRNA (KY855372.1) and PhaR (MF947451.1) sequences have been accessioned in NCBI-GenBank. The results show that Bacillus cereus C113 demonstrated capacity to utilize a variety of carbon sources for PHAs production.

Screening and Biochemical Characterization of Indigenous Polyhydroxyalkanoates Producing Bacteria

“…[50] screened for the presence of PHA synthase using PCR on different strains of bacteria and observed an amplification product of 540bp. Amplification of phaC gene has been reported for isolates such as Bacillus cereus SE-1 [51]; Pseudomonas mendocina PSU [52]; Bacillus substillis [53] and Bacillus cereus C113 [54] using PCR method.…”