World Journal of Microbiology and Biotechnology 6, 39-45 Production of cellulases and hemicellulases by an anaerobic mixed culture from lignocellulosic biomass Romana Tabassum, M.I. Rajoka and K.A. Malik A comparison of different habitats, biogas plant, rumen fluid and sewage sludge, for cellulolytic organisms indicated sewage sludge was the best source. Enrichment culture gave a mixed culture which exhibited CMCase activity as well as extracellular Avicelese, xylanase, ~-gluco- sidase, ~-xylosidase activities and cell- bound ~-glucosidase, and I]-xylosidase production in a synthetic medium with eleven different cellulosic and lignocellu- Iosic substrates. The activity of extra- cellular I~-glucosidase and ~-xylosidase production was significantly higher than endogenous activities, Hemicellulases were induced better than cellulasea. The enzyme system was stable under aerobic conditions. Of the different lignocelluIosic substrates, keller grass was the best inducer of extracellular enzymes. For French summary, see next page. The authors are with the Soil Biology Division, Nuclear Institute for Agriculture and Biology, P.O. Box 128, Jhang Road, Faisalabad, Pakistan. M.I. Rajoka is the Corresponding Author. 9 1990 Rapid Communications of Oxford Ltd. Waste disposal and the production of fuels and chemicals can be achieved by the anaerobic fermentation of cellulosic materials (Lee et al. 1985). The microflora of a complex anaerobic system, such as sewage sludge, consist of various groups of bacteria which may exist in symbiotic association (Khan 1977). An ecosystem initiated from sewage sludge can be maintained in a synthetic medium to carry out cellulose degradation under defined conditions (Khan et al. 1979). To improve the conversion of cellulosic biomass to chemicals and fuels, many cellulolytic aerobic and anaerobic bacteria have been isolated but the rate of cellulose degradation by pure culture is slow and information on the use of anaerobic conversion of biomass for the formation of products other than methane is limited. Cellulolytic anaerobes are also useful in co-culture in the single step conversion of cellulose to sugars and other useful end products (Khan & Murray 1982; Weimer et aL 1977). The present study deals with the production of cellulases and hemicellulases by mixed culture when grown on different cellulosic and lignocellulosic substrates under anaerobic conditions. Some salt tolerant plants such as kallar grass. (Leptochloafusca), Atriplex sp. Napier hybrid and Panicum maximum were used as lignocellulosic substrates. These plants are being used for economic utilization of salt-affected waste lands in Pakistan (Malik et al. 1986). Materials and Methods Source of lnoculum Samples for mixed cultures were obtained from three different habitats namely, bovine-rumen, biogas plant and sewage sludge. Preparation of lnoculum The basal medium (adopted from Patel et al. 1980) had the following composition (mg/1): NaHCO3, 2060; NH4C1 , 680; K2HPO4, 296; KH2PO4, 180; (NH4)2SO4, 150; MgSO4.7H20 , 120; CaC12.2H20 , 61; FeSOg.7H20 , 21; nitrilotriacetic acid, 15; NaC1, 10; MnSO4.H20, 5; COC12.6H20, 0.1; H3BO, 39