Construction Of The Microbial Consortium And Its Study In Cellulosic Waste Bioconversion For Enzymes Production

As a kind of renewable energy and resource, lignocellulose has a low price and a wide source, so can effectively alleviate energy and resource crisis. However, because of its complex structure and low bioconversion rate with monoculture, lignocellulose can not be efficiently utilization in large scale.To realize the aim of high effective and low-cost bioconversion of lignocellulosic materials, this paper focuses on the research of lignocellulosic waste fermentation by consortium.In this paper, defoliation was used as substrate to demonstrate the advantages of solid state fermentation by mix-culture and substrate compound. A microbial consortium was constructed to produce a feed multienzyme from defoliation, supplemented with orange peels and wheat bran. Single-factor experiment and response surface methodology were adopted to optimize the substrate compound and moisture content. The results showed that a mixture of deloliation, wheat bran and orange peels of9:8:3(w/w/w), a moisture ratio of1:2.2(solid:liquid) were found to be optimal for cellulase production of CMCase(5.54U/gds), FPase(1.1U/gds). The optimal production of other enzymes were amylase(71.61U/gds), pectinase(16.68U/gds) and xylanase (4.5U/gds), but the optimized conditions were different from cellulase.The bacterial and fungi composition in consortium were analyzed, and the result demonstrated that there were plenty kind of microbe in the consortium, such as Aspergillus, Penicillium, Trichoderma, Rhizopus, Pseudomonas, Dysgonomonas, Delftia, etc. And the microbial consortium can keep a certain amount of enzyme production after a storage of8months at room temperature.Besides defoliation, another3kind of lignocellulosic waste (paper, castock and cauliflower) were studied in the same way. The results demonstrated that the optimal enzymes production in paper were CMCase(10.1U/gds), FPase(2.18U/gds), amylase(137.87U/gds), pectinase(23.4U/gds) and xylanase(9.76U/gds). The optimal enzymes production in castock were CMCase(13.47U/gds), FPase(2.92U/gds), amylase(152.59U/gds), pectinase(52.27U/gds) and xylanase(11.44U/gds). The optimal enzymes production in cauliflower rod were CMCase (10.54U/gds), FPase(2.46U/gds), amylase(126.02U/gds), pectinase(49.59U/gds) and xylanase (15.87U/gds). And almost all of these enzymes can keep a high production after a storage of8months at room temperature.