Spent coffee grounds (SCG) are solid fraction wastes deriving from coffee industries, the disposal of which
represents a serious environmental issue. This work aims at the conversion of hydrolysate of SCG (SCGH)
into polyhydroxyalkanoates (PHA) by Burkholderia cepacia. The bacteria was capable of SCGH utilization
and production of copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate [P(HB-co-HV]. Levulinic acid
present in SCGH probably served as the precursor of 3HV for the copolymer biosynthesis. To improve
the PHA yields, various detoxification methods were tested. The extraction of polyphenols from SCG by
ethanol prior to the hydrolysis seems to be the most promising, since, apart from the fact that it enhanced
the PHA yields by about 25%, polyphenols extracted from SCG may represent important side products,
because they might be used for the production of functional foods and other high value products.