Comparison of different aerobic sludge on enriching polyhydroxyalkanoate mixed microbial culture using lactic acid fermentation broth of agricultural wastes

•Lactic acid is the major composition of the fermentation broth for PHA production.•Effective MMC was enriched by using pig farm sludge and SRTs of 8 days.•PHA yield and content of 0.57 gPHA-COD/gCOD and 50% were in accumulation reactor.•The different MMCs tended to be similar and the dominant bacteria was Paracoccus.