Taking Manioc Waste As Main Material To Produce Pectinase In Fermentation And Study On Its Application Value

Pectinase is one of the most widely used proteases in the world, which has high economic value and application potential, and has been practiced in many areas, such as food?textile?medicine and so forth.A strain(Aspergillus niger) able to produce pectinase which screened from the corrupted cassava dregs was taken as starting strain in this paper, then a gene-stability and high-yield strain called PP-7 had been gotten by UV mutagenesis. Under fellow conditions:pH= 6,temperature 32?, inoculation quantity 4%, water addition quantity 1 g/g,bottling capacity 12g, after 72h fermentation, average output value could reach 14401U/g.By single factor and orthogonal experiments, optimum enzyme-producing culture conditions had been gotten:water addition quantity 1.4g/g, pH=5, inoculation quantity 4%, bottling capacity 20g. The influence of each factors:water addition quantity> pH> bottling quantity>inoculation quantity. Optimum material conditions were:bean cake powder: cassava dregs=3:7, ammonium sulfate4.8%, potassium dihydrogen phosphate content0.8%, Twain 80 content 0.12%.The influence of respectable factors:bean powder> two potassium hydrogen phosphate> ammonium sulfate> Twain 80. Under the optimum conditions, after 72h fermentation, the average output value could reach 21102.25U/g.Metal ions with positive effect on homemade pectinase:Ca2+?Mg2+?Fe2+, metal ions with obvious negative effect:Zn2+?Ba2+.almost without effect:Cu2+?Na+?K+The optimum act pH value of self made enzyme:4, and enzyme activity can keep relatively high level when pH keeps between 2-6, and keep high enzyme stability when pH keeps between2-5.and the stability of pH was relatively high when pH was 2-5. The optimum act temperature is 50?, when temperature keeps between 30-50?,the enzyme activity keeps relatively high, the highest thermal stability temperature is 30?, after over 45?, the rapid decline in thermal stability appears.With kiwi fruit as the research object, using the homemade enzyme to increase the juice yield rate. Influence of respectable factors:temperature> processing time> enzyme quantity, the optimum treatment conditions:the addition amount of enzyme 0.3%, processing temperature of 40 degrees, processing time 120min. Juice yield can reach 79.7%, which is improved by 27.2% compared with 52.5% of natural treatment.Taking cassava residue as main material, screening suitable strain, reasonably adjusting culture conditions, efficient pectinase production can attain. And comprehensive utilization path of cassava residue has been broadened at the same time.