The present invention provides an anaerobic digestion process for the treatment of organic waste materials, which process comprises a bacterial process that is carried out in the absence of oxygen and wherein said process comprises digestion, in which said waste is fermented in tanks at an elevated temperature, and wherein said process results in the production of biogas, which can be used in generators for electricity production and/or in boilers for heating purposes, the comprises treating an organic waste with a composition comprising a fermentation supernatant containing active enzymes from a Saccharomyces cerevisiae culture; and a non-ionic surfactant, wherein said nonionic surfactant may be selected from the group consisting of ethoxylated nonylphenol and ethoxylated octyl phenol.
