Enzymatic Hydrolysis Of Eichhornia Crassipes By Cellulase

Water hyacinth (Eichhornia crassipes) as an invasivespecy has caused seriousproblem in our country due to its fast spread and crowed growth. Water hyacinth couldbe converted into biomass energy through cellulase. The key factors to efficiently usewater hyacinth as biomass energy are high activity cellulase and a efficient pretreatmentmethod. This work would optimize the production of cellulase by submerge fermentationof T. virens ZY-01, develop a excellent pretreatment for water hyacinth, and study thecharacteristics of degradation of water hyacinth by cellulase.First, the submerge medium of T. virens ZY-01is optimized. The seed cultivationtime is3days and fermentation period is5days. The best medium is CMC-Na14g/L,lactose5g/L, ammonium sulfate6g/L, potassium dihydrogen phosphate2g/L,potassium chloride1.4g/L, magnesium sulfate1g/L, Tween-808mL/L, sucrose1g/Lby single factor optimization method and orthogonal experiment optimization. And theoptimized fermentation conditions were the quantity of5%, with fluid volume ratio0.14,the initial pH is5, it can get enzyme activity is0.15U/mL (filter paper activity),41timeshigher than the original submerge medium.In order to improve the hydrolysis efficiency of water hyacinth, we study thepretreatment of the water hyacinth. The water hyacinth was physics treatment such asdrying, crushing, then it is further treated with acid or alkali method. The resulit showthat alkali treatment is suitable pretreatment method to water hyacinth. The optimumconditions are: NaOH7g/L,60min, liquid-solid ratio20,120℃. Add FPA50U/g(substrate)at pH4.8,50℃,250rpm.The optimum reaction pH and temperature of cellulase to alkali pretreated waterhyacinth is pH4.8and50℃, and90%cellulose could be conversed to glucose. Thecellulase hydrolysis rate decline after12hours,48hours to smooth. By means of IR,SEM analysis of the pretreatment and hydrolysis for the structure change of waterhyacinth, found that the main mechanism of water hyacinth cellulose enzyme solution isto destruct the C-H bond of cellulose, benzene ring will affects enzyme hydrolysis andlead to the enzyme adsorption is invalid, and enzyme hydrolysis mainly throughadsorption biomass surface, and then gradually to go in, can form a concave hole.This work shows that water hyacinth is a good feedstock for cellulase as a biomass.