Effective production of low crystallinity Poly(3-hydroxybutyrate) by recombinant E. coli strain JM109 using crude glycerol as sole carbon source. (September 2015)

• Record Type: Journal Article
• Authors: Ganesh, Mohan; Senthamarai, Arivazhagan; Shanmughapriya, Santhanam; Natarajaseenivasan, Kalimuthusamy
• Is Part Of: Bioresource technology. Volume 192(2015)
• Page Start: 677
• Page End: 681
• Publication Date: 2015-09
• Subjects: Glycerol -- P(3HB) -- Low crystallinity -- Crystallinity index; 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.2015.06.042
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Replacement of commercial carbon sources for P(3HB) production. Statistical optimization of culture condition for maximal production of P(3HB). Model validation was performed by batch fermentation in a 7.5 L bioreactor. Analysis of thermophysical properties of the produced P(3HB). Produced P(3HB) had high MW (∼2.8 × 10 6 ) and low crystallinity of ∼30%. Abstract: Utilization of bio-diesel by-products (glycerol) for microbial polymer production has created a novel biorefinery concept. In the present study, recombinant Escherichia coli JM109 was used for the production of P(3HB) from glycerol as carbon source. Batch fermentation in a 7.5 L bioreactor with the statistically optimized culture condition (pre-treated glycerol: 27.5 g/L and casein hydrolysate: 5.25 g/L) scaled up the P3HB production to 65% (∼8 g/L). FTIR, 1 H and 13 C NMR analysis proved the polymer produced to be P(3HB). Gel permeation chromatography, Differential Scanning Calorimetry (DSC) and thermogravimetric analysis (TGA) demonstrated the produced P(3HB) to have high molecular weight (2.84 × 10 6 ) and lowered crystallinity (∼30%) compared to commercial polymer. Integrating the production efficiency and the thermal characteristics of the polymer produced by recombinant E. coli, the viability and sustainability of biofuels and biopolymers for economic human need could be enhanced.