Efficient utilization of crude glycerol as fermentation substrate in the synthesis of poly(3-hydroxybutyrate) biopolymers

One refined and two crude glycerol (from biodiesel production) samples were utilized to produce poly(3-hydroxybutyrate) (PHB) by Pseudomonas oleovorans NRRL B-14682. A batch culture fermentation protocol including 1% glycerol and an aeration rate of 3 standard liters per minute proved best for PHB synthesis (av. yield = 1.0 ± 0.2 g/L at 48 h) and efficient glycerol utilization. PHB molecular weights decreased as MeOH concentration increased. Refined glycerol resulted in PHB polymers with number average molecular weights (M n) of 314,000 g/mol which decreased by 17 and 90% as MeOH media concentrations increased to