Rami Reddy Tadi S, Dutt Ravindran S, Balakrishnan R, Sivaprakasam S. Recombinant production of poly-(3-hydroxybutyrate) by Bacillus megaterium utilizing millet bran and rapeseed meal hydrolysates.
BIORESOURCE TECHNOLOGY 2021;
326:124800. [PMID:
33556706 DOI:
10.1016/j.biortech.2021.124800]
[Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 06/12/2023]
Abstract
Fermentative poly-3-hydroxybutyrate (PHB) production is mainly limited by the cost of raw material. In this present study, low-cost feedstock viz., millet bran residue (MBRH) and rapeseed meal hydrolysates were successfully utilized for PHB production. Metabolic engineering of Bacillus megaterium by co-expression of both precursor (phbRBC) and NADPH cofactor regeneration (zwf) genes resulted in 2.67-fold enhancement in PHB accumulation compared to wild strain. Modified logistic model characterized B.megaterium growth and PHB production effectively. The kinetic analysis proved that maximum cell concentration (15.01 g.L-1) and growth-associated constant (0.22 g.g-1) were found to be higher for initial MBRH concentration (S0 = 20 g.L-1). PHB production kinetics elucidated its expression in B.megaterium was growth-associated. PHB synthesized by B.megaterium was characterized using FTIR, NMR, XRD, DSC/TGA, FESEM and the physio-chemical properties enumerated its as a potential biodegradable plastic for industrial application.
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