Hydrolases does not belong to oxidoreductase family. Oxidoreductases are enzymes which catalyse the transfer of electrons from one molecule (reductant) to another molecule (oxidant). It plays a major role in biodegradation pathways. Enzymes present in oxidoreductase family are oxygenase, reductase, dehydrogenase and peroxidase. Ref: Microorganisms in Environmental Management: Microbes and Environment By T. Satyanarayana, Bhavdish Narain Johri, Anil Prakash, Page 233; Biochemical Engineering By Gummadi, Page 89