Studies On Synergism Of Cellulase, Esterase And Xylanase On Corn Stalk

Stalk is a renewable resource. The mainly methods on hydrolysis of cellulose from stalk are using cellulase and acid. It is a hot potato how can improve the rate of enzymatic hydrolysis on cellulose in the world. It becomes important to combinatorial optimization and operating cost reduction.Three different pretreatment methods were tested to study the effect on hydrolysis of cellulose from corn stalk. The dilute-acid,dilute-alkali and sodium sulfite anhydrous pretreatment of corn stalk were carried out, The pretreatment of obtained sample was conducted for cellulose enzymolys is saccharification. The results showed that the optimum condition for enzymatic hydrolysis is at temperature of 50℃, pH of 4.8, ratio of solid to liquid 1:30, enzyme concentration of 4 g/L, and the hydrolysis time of 24 h. Under the optimized condition, the rate of enzymatic hydrolysis on corn stalk pretreatment using sodium sulfite anhydrous was 39.07%, which is four multiple higher than that of corn stalk hydrolysis without pretreatment. Pretreatment destroyed the fibrous structure of corn stalk significantly. Relative good rate of enzymatic hydrolysis on corn stalk pretreatment using sodium sulfite anhydrous can be achieved。The study showed that the rate of enzymatic hydrolysis on synergism of cellulase,FAE and xylanase was higher than two enzymes, the rate of two enzymes was higher than ones. The rate of enzymatic hydrolysis was different with different orders of adding enzymes when synergistic reaction,the optimum order was adding them at one time,and the rate of enzymatic hydrolysis on synergism was 79%, which is higher than that of cellulase(65.63%). It is concluded that FAE, xylanase and cellulase have great synergistic effect, FAE,xylanase can help cellulase hydrolyze natural lignocellulose and enhance hydrolytic efficiency.The effects of eight kinds of metallic ions on cellulase,FAE and xylanase activity were studied. The results were as following:The effects of metallic ions on enzyme activity were complicacy. The enzyme activity with different mental ions was different. When the concentration of mental ions was 1×10-3mol/L,cellulase activity improved by Cu2+, Mn2+, Ca2+, Na+, Mg2+, Fe2+, xylanase activity improved by Cu2+, K+, Ca2+, Na+, Fe2+, FAE activity improved by Cu2+, Ca2+, Zn2+,Cu2+, Ca2+ andNa+ had the strongest activation effect on synergism of cellulase,esterase and xylanase.The rate of enzymatic hydrolysis on addition of metallic ions was 82.99%, it is higher than that of whithout metallic ions(79%).