This study identifed and quantifed microbial populations in cattle manure slurry, responsible for anaerobic degradation of kitchen waste using activity tests and Most Probable Number for key trophic groups in the process. Hydrolytic, acidogenic, acetogenic, specifc methanogenic acetoclastic and hydrogenotrophic activities were evaluated using as model substrates starch, glucose, propionate-butyrate mix, acetate and formate, respectively. Anaerobic digestion from kitchen waste was developed for 35 days in batch reactors of 50mL containing an inoculums/substrate ratio of 3. Samples were taken from digesters every 7 days to evaluate microbial populations by counting metabolic groups. This study demonstrates that there is an association between biomass activity and population of trophic groups related. Additionally, CMS is an inoculum with high quality to start-up the anaerobic process with kitchen waste. On the other side, MA/FB ratio and MA/SRB ratio are important microbial parameters to evaluate performance of reactor. Finally, AD from kitchen waste reached a yield coeffcient of 0.41m3 CH4/kgVS using cattle manure sludge as inoculum. Keywords: trophic groups, metabolic groups, kitchen waste, cattle manure slurry, MPN, microbial activities.