Industries all over the world generate huge amounts of wastewater that must to be treated before discharge into surface waters. The organic carbon in the wastewater can be recovered in the production of polyhydroxyalkanoates (PHA) using microbial mixed cultures that were previously enriched in PHA-accumulating bacteria. This strategy recovers carbon source from wastewater reducing significantly PHA production costs due to the use of an inexpensive substrate.
A microbial mixed culture enriched in Thauera sp. was used for the production of PHA from acetate (benchmark) and several industrial wastewaters, namely brewery, paper mill and sugar. In the case of acetate the PHA storage capacity in percent of the cell dry weight reached 75%, while a maximum of 55% was obtained with the industrial wastewaters. A copolymer of PHB and PHV was obtained with industrial wastewater and a homopolymer of PHB with acetate. The PHB content in the copolymer is considerably higher than the PHV content. The thermal properties of the copolymers as well as their biodegradability are being accessed.