A novel pretreatment biotechnology for increasing methane yield from lipid-rich wastewater based on combination of hydrolytic enzymes with Candida rugosa fungus

Lipid-rich wastewater from the local dairy industry (cheese whey) in the Galilee, Israel was hydrolyzed by using two different sources of lipase as hydrolytic enzymes: fungal (Candida rogusa lipase-AY) and animal porcine pancreatic lipase(PPL). Pretreatment efficiency was verified by comparative biodegradability tests of raw and treated wastewater samples. Simultaneous hydrolysis and anaerobic digestion in the same reactors were also tested. Enzymatic pretreatment of these samples at a concentration of 0.05 w v-1 showed organic matter removal of 90% and methane formation increases of 140% for the fungal source enzyme (i.e., AY), while for the animal source enzyme (i.e., PPL) was 86 and 130%, respectively. Enzymatic pretreatment led to significant methane formation which was obtained only for moderate substrate concentration (initial chemical oxygen demand of 15 gL-1); While in high concentrated lipid-rich wastewater led to methane yield inhibition. The main finding was that the comb...