A strategy for dual biopolymer production of P(3HB) and γ-PGA

Abstract

BACKGROUND Production of biopolymers has gained considerable attention because of their biodegradability, biocompatibility, and as suitable replacements for mineral-based polymers. Despite advances in the production process, a notable drawback still exists due to high production cost. The aim of this work is to provide a production strategy for cost reduction. The suggested process may be adapted to other polymers, useable by a wide audience in biopolymer research. RESULTS Dual production of two commercially important biopolymers, P(3HB) and γ-PGA, in a single batch from cheap substrates was studied, as proof of concept, for feasible low cost dual biopolymer production. Dual production from a single batch yielded 1 g L−1 P(3HB) and 0.4 g L−1 γ-PGA using Bacillus subtilis OK2 (B. subtilis OK2). When orange peel was substituted as a cheap carbon source for dual production, coupled pH and dissolved oxygen control proved to be essential to overcome the inhibition imposed by the non-sugar components of the substrate. Cell lysis and release of P(3HB) granules in the dual production medium can be exploited of as a new approach for separation of this polymer. CONCLUSION This proof of concept study provides a new approach from upstream to downstream processing for low cost production of dual biopolymers. © 2017 Society of Chemical Industry