Integrated solid-state enzymatic hydrolysis and solid-state fermentation for producing sustainable polyhydroxyalkanoates from low-cost agro-industrial residues

Polyhydroxyalkanoates (PHA) are biodegradable bioplastics of interest as potential substitutes petroleum-derived plastics that can be produced starting from lignocellulosic-derived residues. This study presents the combined solid-state enzymatic hydrolysis (SSEH) and fermentation (SSF) a sustainable approach for obtaining PHA using leftovers brewer's spent grain (BSG), grape pomace (GP) olive-mill solid waste (OSW) substrates. SSEH performance was influenced by intrinsic characteristics each residue, temperature, type extract used. Thus, maximum sugars release (0.16 g g?1 dry residue (gTS)) obtained with GP. Furthermore, coupling SSF promoted yield increases up to 54%, 41% 31% BSG, GP OSW respectively, compared alone. The achieved hydrolyzed BSG 12.5 mg TS (0.33 kg?1 h?1). Results show this an attractive alternative obtain bioproducts such sustainably in residue-based systems.