Enriching polyhydroxyalkanoates (PHA) producing microorganisms by complex organics from quickly alkaline fermentation liquor

To reduce production cost and shorten time span of fermentation phase for polyhydroxyalkanoates (PHA), liquor from rapid alkaline treated (pH 12, 24 h) waste activated sludge containing principally proteins and carbohydrates was used to enrich PHA-producing microorganisms. The liquor containing 3930 mg/L proteins and 1230 mg/L carbohydrates was utilized to effectively acclimate PHA-producing strains from waste activated sludge seed in 20 d which produced PHA at a content of 400 mg/g dry solid. The poly-β-hydroxybutyrate (PHB) and poly(3-hydroxyvalerate) (PHV) were the main constitutes of PHA, with PHB 2.65-fold higher than PHV. The PHA-producing bacterial community was identified.

► We enrich PHA-producing strains using hydrolysate from waste activated sludge.
► Quick alkaline treatment was used to produce feed with proteins and carbohydrates.
► PHA was produced at a comparable rate to literature results.
► Complex organic compounds can be used to acclimate PHA-producing strains.