Production of PHA from whey by indigenous microflora and activated sludge: preliminary investigation

Milk whey was employed to produce polyhydroxyalcanoates (PHA), using as inoculum either whey indigenous microflora or enriched activated sludge deriving from a dairy wastewater treatment plant. The aim of the present study was to test the capability of mixed consortia to produce PHA directly from lactose. The experimental runs demonstrated that milk whey lactose can constitute a cheap carbon source to synthesize PHA in fermentations where the microorganisms are represented by indigenous microorganisms or enriched activated sludge: this result constitutes an evident advantage since whey pre-treatment and aseptic conditions are not required. Tests with commercial whey powder (Molkolac®) and on raw milk whey showed a PHA production around 10 % (by weight on dry biomass)