Recombinant production of poly-(3-hydroxybutyrate) by Bacillus megaterium utilizing millet bran and rapeseed meal hydrolysates. (April 2021)

• Record Type: Journal Article
• Authors: Rami Reddy Tadi, Subbi; Dutt Ravindran, Som; Balakrishnan, Rengesh; Sivaprakasam, Senthilkumar
• Is Part Of: Bioresource technology. Volume 326(2021)
• Publication Date: 2021-04
• Subjects: Poly-3-hydroxybutyrate -- Metabolic engineering -- Bacillus megaterium -- Millet bran hydrolysate -- Kinetic modeling; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2021.124800
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Co-expression of phaRBC, zwf genes enhanced PHB accumulation in B.megaterium . Novice attempt of utilizing millet bran hydrolysate for PHB production. Rapeseed meal hydrolysate employed as a nitrogen source for PHB production. Maximum achieved PHB content of dry cell mass (24.14% w/w) was achieved. The modified logistic model demonstrated the dynamic behavior of B.megaterium. 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.