Composite Degradation Strains Synergistic Fermentation Of Cassava Dregs Technology Research

Cassava is the root of euphorbiaceae plants, mainly distributed in the tropics. The cassava planting area has been increased to 15 million mu in 2015, is second only to rice, sweet potatoes, sugar cane and the fifth largest corn crop. After into cassava starch cassava made each year, the rest of the by-products of about 1.5 million tons of cassava dregs. Scrap processing cassava residue problem has been bothering people. Cassava dregs contain high cellulose, used for biomass extraction has the very high development potential, but in addition to as fuel, feed has not been further use. This experiment using microorganisms as disintegrator ability nature, degradation of cassava dregs, and made into compound inoculants. Using nitrogen-fixing bacteria and cellulose decomposing bacteria into compound strains, medium to add the cassava dregs were administered by optimizing the ratio of strain and fermentation technology, cellulose decomposition microbes degradation of cellulose in cassava dregs, at the same time promote the growth of azotobacter, and greatly increase the nitrogen content in the fermented product, full use of the cassava dregs of biomass resources, reduce waste cassava residue pollution to the environment.In this paper,through a series of experiments to the following conclusion:1?Provided by the lab 6 strains of nitrogen-fixing bacteria and cellulose decomposing bacteria strains, respectively, to cultivate and to determine the OD value of azotobacter and determination of total nitrogen and cellulose decomposing bacteria of CMC enzyme activity, the data is from high to low arrangement, through the comparison, select growth obciously the best 2 strains of nitrogen-fixing bacteria, and 2 plants of cellulose decomposing bacteria. Identification of two strains of nitrogen-fixing bacteria for Xanthobacter agilis and Azotobacter chroococcum, two plant cellulose decomposing bacteria for Bacillus lichenifpus and Aspergillus versicolor. Total nitrogen content of Xanthobacter agilis reached 1.462 mg/m L, Azotobacter chroococcum reached 1.435 mg/m L, CMC enzyme activity of Bacillus lichenifpus reached 2560.5 ?g?30min^-1?m L^-1, Aspergillus versicolor reached 2616.0 ?g?30min^-1?m L^-1.Result all bacteria through the antagonism between not antagonistic, bacteria can be made into composite mixed fermentation, the degradation of cassava dregs.2?To the fermented liquid of total nitrogen, CMC enzyme activity, and reducing sugar content as an index, select 4 isolates of vaccination. Experimental results show that Xanthobacter agilis ? Azotobacter chroococcum ? Bacillus lichenifpus and Aspergillus versicolor vaccination rate are 2 % [suspended bacteria?spore? fluid volume / conical bottled quantity volume, the ellipsis]. After 72 h of fermentation, total nitrogen is 2.855 mg/m L, CMC enzyme activity reached 3391.7 ?g?30min^-1?m L^-1.3?To the fermented liquid of total nitrogen and CMC enzyme activity as an index, degradation of cassava dregs medium nitrogen source selection. The experimental results show that soybean meal as the best nitrogen source: after 72 h of fermentation, total nitrogen is 2.996 mg/m L, CMC enzyme activity reached 3936.3 ?g?30min^-1?m L^-1. In fermented liquid of total nitrogen and CMC enzyme activity as an index, slag powder, adding 2% of cassava for degradation of cassava dregs fermentation medium available carbon source selection.4?To the fermented liquid of total nitrogen and CMC enzyme activity, and reducing sugar content as an index, optimize the degradation of cassava dregs fermentation culture medium formula. The experimental results show that the optimal culture medium formula for: cassava dregs powder 50.0 g, mannitol 20.0 g, soybean powder 3.0 g, KH2PO4 1.0 g, Ca Cl2 0.2 g, Mg SO4 ? 7 H2 O 0.3 g, distilled water 1 000 m L, p H=7.2 7.3. After 72 h of fermentation, total nitrogen is 3.991 mg/m L, CMC enzyme activity reached 4071.7 ?g?30min^-1?m L^-1.5?To the fermented liquid of total nitrogen, CMC enzyme activity, and reducing sugar content as an index, the degradation of cassava dregs fermentation process optimization. The experimental results show that the optimal fermentation technology for initial p H=7.0, culture temperature 40 ?,5 % inoculation amount, culture 120 m L/250 m L conical flask, fermentation under 140 r/min speed. After 72 h of fermentation, total nitrogen is 4.258 mg/m L, CMC enzyme activity reached 4227.6 ?g?30min^-1?m L^-1.Compound bacteria have efficient tapioca residue degradation ability, compared with the single strain fermentation, filtering to the strongest growth ability in nitrogen-fixing bacteria Xanthobacter agilis, total nitrogen content in fermented liquid of only 1.462 mg/m L, amount of total nitrogen in the compound bacteria fermented liquid is 4.258 mg/m L, a 191.24% increase over the Xanthobacter agilis; Cellulose decomposing bacteria, bacillus licheniformis, the strongest growth ability in fermented liquid of CMC enzyme activity was only 2560.5 ?g?30min^-1?m L^-1, compound bacterium in the fermented liquid CMC enzyme activity, 4227.6 ?g?30min^-1?m L^-1, a 65.11% increase over the bacillus licheniformis. So compound bacterium by degradation of cassava dregs, can solve the azotobacter nitrogen fixation efficiency low and need to the problem of energy. Compound bacteria compared with single bacterium fermentation, fixed more nitrogen in the air, cellulose decomposing bacreria can produce higher enzyme activity, and can reduce the fermented product of reducing sugar of cellulolytic enzyme inhibition. To sum up, the synergy of compound bacteria that nitrogen-fixing bacteria and cellulose decomposition microbes both mutual reciprocity and mutual benefit, enhanced biological effect, achieve the efficient degradation of cassava dreys and produce more beneficial to the purpose of the degradation products of agricultural production.