Production Of Multienzyme Preparations Under Solid-state Fermentation (SSF) On Lotus Seed Shell

The Lotus Seed Shell contain abundant fiber and minerals such as nitrogen andphosphorus elements, so they can be used as the suitable substrate to support growthof microorganisms. Enzymes,such as cellulase,sucrose,pectinase and xylanase areplaying an increasingly important role in the feed industry. The research described inthis paper was aimed at studying the utilization of Lotus Seed Shell as substrates forcompound enzyme production,and predominant strain was obtained finally which canproduce higher enzyme. The solid-state fermentation (SSF) process condition wasoptimized and the thermal stability of compound enzyme was studied.The result ofthis study was reported as follow:1. Through analysis and comparison the productivity of multienzyme of Penicill-ium oxalicum,Rhizomucor Variabilis,Eupenicillium javanicum,Aspergillus aculeatusand Aspergillus niger, and firmly establish Rhizomucor Variabilis and Aspergillusaculeatus as strain of the bacteria fermentation to produce feed enzyme preparation.2. Through single factor experiment established different temperature, differenttime, different ration of water and material, different initial pH as the critical factorsof solid-state fermentation to produce compound enzyme.Other non-critical factorsfor producing of above multiple enzymes was: the mass ratio of lotus seed shell andsoybean meal is7:3,1g rice straw powder as carbon source,0.1g (NH4)2SO4asnitrogen source,0.1g Na2HPO4as inorganic salt and5%of the quantity((106~107permilliliter).Using response surface methodology(RSM) to optimize the four critical factors,The optimum reaction conditions of Aspergillus aculeatus solid-state fermentationwas obtained as follows: incubation temperature28.22°C, incubation time81.40h,the ratio of material to water is1:1.08, the initial pH is5.12. At this point, the enzymeactivities of CMC, β-glycosidase, invertase, pectinase, pectate lyase and xylanasecould achieve14.58U/g,51.55U/g,133.12U/g,140.80U/g,130.70U/g,63.17U/g,respectively. Comparing the average results between experimental and modelprediction by three parallel test, verify the relative error of the enzyme activity were4.22%、0.37%、3.74%、11.35%、6.10%、3.17%, respectively. It meet the requirementsof the test error.By means of researching the result of composite enzyme activity along with thechange of time in four temperature under80°C,40°C,25°C and4°C show that the loss of enzyme activity is less than50%under the condition of80°C for4h, thecondition of40°C for10d, the condition of25°C for20d, respectively. And the loss ofpectate lyase activity is less than50%within30d when the temperature descends to4°C, the others less than80%.3.Through single factor experiment established the optimum reaction conditionsof Rhizomucor Variabilis solid-state fermentation was obtained as follows: incubationtemperature28°C, incubation time64h, the ratio of water to material is1:1.5, theinitial pH is4.2,the mass ratio of lotus seed shell and soybean meal is9:1,1g ricestraw powder as carbon source,0.1g (NH4)2SO4as nitrogen source,0.1g Na2HPO4asinorganic salt and3%of the quantity((106~107per milli-liter). With this condition, theenzyme activities of CMC, β-glycosidase, invertase, pectinase, pectate lyase andxylanase could achieve10.43U/g,14.02U/g,22.95U/g,68.23U/g,62.35U/g48.12U/g,respectively.