Polyhydroxyalkanoate biosynthesis and simultaneous remotion of organic inhibitors from sugarcane bagasse hydrolysate by Burkholderia sp.

Burkholderia sp. F24, originally isolated from soil, was capable of growth on xylose and removed organic inhibitors present in a hemicellulosic hydrolysate and simultaneously produced poly-3-hydroxybutyrate (P3HB). Using non-detoxified hydrolysate, Burkholderia sp. F24 reached a cell dry weight (CDW) of 6.8 g L-1, containing 48 % of P3HB and exhibited a volumetric productivity (P-P3HB) of 0.10 g L-1 h(-1). Poly-3-hydroxybutyrate-co-3-hydroxyvalerate copolymers (P3HB-co-3HV) were produced using xylose and levulinic acid (LA) as carbon sources. In shake flask cultures, the 3HV content in the copolymer increased from 9 to 43 mol% by adding LA from 1.0 to 5.0 g L-1. In high cell density cultivation using concentrated hemicellulosic hydrolysate F24 reached 25.04 g L-1 of CDW containing 49 % of P3HB and P-P3HB of 0.28 g L-1 h(-1). Based on these findings, second-generation ethanol and bioplastics from sugarcane bagasse is proposed.