TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: A microbially-derived cellulase activity of at least 30 filter paper units (FPU)/l is provided by the microbial consortium providing microbial fermentation. The incoming MSW stream is inoculated with an inoculum of microorganisms naturally occurring in the waste, and raised on local waste or components of local waste as a food source in fermentation conditions of temperature of within 37-55 degrees C, preferably 45-50 degrees C, and at a pH of 4.2-6. The water content is added to the waste to achieve an appropriate non-water content. An appropriate non-water content is achieved by adding to the MSW a constant mass ratio of water of 0.5-2.5 kg of water/kg of MSW. The cellulase activity is added as an isolated cellulase preparation, and added by inoculation with a selected microorganism that exhibits extracellular cellulase activity. The slurry of biodegradable components is subject to post-fermentation following separation of non-degradable solids. The inoculation of the incoming MSW stream is provided by recycling wash waters or process solutions used to recover residual organic material from non-degradable solids. The inoculation of the incoming MSW stream is provided before or concurrently with the addition of enzymatic activities or with the addition of microorganisms that exhibit extracellular cellulase activity, where at least 40 wt.% of the dissolved volatile solids of the slurry of biodegradable components comprises lactate and at least 40 wt.% of the non-water content of the slurry of biodegradable components comprises dissolved volatile solids. The microbial fermentation is conducted within the temperature of 45-50 degrees C. The MSW is heated to a temperature not higher than 75 degrees C. The sorting of non-biodegradable solids is performed within 36 hours or 24 hours from the start of enzymatic hydrolysis. The ethanol or lactate is first removed from the slurry of biodegradble components prior to anaerobic digestion to produce biomethane. Preferred Components: The incoming MSW stream comprises waste fractions derived from general industry. The non-biodegradable solids separated comprise at least 20% of the dry weight of the MSW. The non-biodegradable solids separated comprise at least 20% by dry weight of recyclable materials.