Microbial Formation of Polyhydroxyalkanoates from Forestry-Based Substrates

摘要

This study reports on the bench-scale production of poly-β-hydroxybutyrate-co-β-hydroxyvalerate (P(3HB-co-3HV)) by Burkholderia cepacia using detoxified aspen-derived hemicellulosic hydrolysates and levulinic acid as renewable, forestry-based platform substrates. Shake-flask cultures were found to produce P(3HB-co-3HV) at yields of 0.5-2.0 g/L and compositions of 16-52 mol% 3HV were achieved by adding 0.25-0.5% (w/v) levulinic acid as a cosubstrate. Physical characterizations revealed a relatively wide thermal processing range for the copolymers, with a 105℃ average differential separating the respective melting and decomposition temperatures. Molecular mass determinations also supported the potential of these polyesters for commercial processing, with viscosity-derived M_v values averaging 557 kDa.