Industrial scale production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)

Abstract

Large scale production of poly(3-hydroxy-butyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] by Aeromonas hydrophila 4AK4 was examined in a 20,000 1 fermentor. Cells were first grown using glucose as a carbon source, and polyhydroxyalkanoate (PHA) biosynthesis was triggered by the addition of lauric acid under conditions of limited nitrogen or phosphorus. When cells first grown in a medium containing 50 g glucose 1(-1) were further cultivated after the addition of 50 g lauric acid 1(-1) under phosphorus limitation, a final cell concentration, PHA concentration and PHA content of 50 g 1(-1), 25 g 1(-1), and 50 wt%, respectively, were obtained in 46 h, equivalent to PHA productivity of 0.54 g 1(-1) h(-1). The copolymer produced was found to be a random copolymer, and the 3HHx fraction was 11 mol%.