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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Healthy Processed Foods Research » Research » Publications at this Location » Publication #221469

Title: Nonionic Surfactants and Noncatalytic Protein Treatment on Enzymatic Hydrolysis of Pretreated Creeping Wild Ryegrass

Author
item ZHENG, YI - UC DAVIS, DAVIS, CA
item Pan, Zhongli
item ZHANG, RUIHONG - UC DAVIS, DAVIS, CA
item WANG, DONGHAI - KANSAS STATE UNIV., KS
item JENKINS, BRYAN - UC DAVIS, DAVIS, CA

Submitted to: Applied Biochemistry and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/27/2007
Publication Date: 12/1/2007
Citation: Zheng, Y., Pan, Z., Zhang, R., Wang, D., Jenkins, B. 2007. Non-ionic Surfactants and Non-catalytic Protein Treatment on Enzymatic Hydrolysis of Pretreated Creeping Wild Ryegrass. Applied Biochemistry and Biotechnology. DOI 10.1007/s12010-007-8035-9.

Interpretive Summary: Our previous research has shown that saline Creeping Wild Ryegrass (CWR), Leymus triticoides, has a great potential to be used for bioethanol production due to its high fermentable sugar yield, up to 85% cellulose conversion of pretreated CWR. However, the high cost of enzyme is still one of the obstacles making large-scale lignocellulosic bioethanol production economically difficult. It is desirable to use reduced enzyme loading to produce fermentable sugars with a high yield and alow cost. The research results showed that the addition of additives could be a promising technology to improve the enzymatic hydrolysis by reducing the enzyme activity loss due to nonproductive adsorption.

Technical Abstract: Our previous research has shown that saline Creeping Wild Ryegrass (CWR), Leymus triticoides, has a great potential to be used for bioethanol production due to its high fermentable sugar yield, up to 85% cellulose conversion of pretreated CWR. However, the high cost of enzyme is still one of the obstacles making large-scale lignocellulosic bioethanol production economically difficult. It is desirable to use reduced enzyme loading to produce fermentable sugars with a high yield and a low cost. To reduce the enzyme loading, the effect of an addition of nonionic surfactants and noncatalytic protein on the enzymatic hydrolysis of pretreated CWR was investigated in this study. Tween 20, Tween 80 and bovine serum albumin (BSA) were used as additives to improve the enzymatic hydrolysis of dilute sulfuric acid pretreated CWR. Under the loading of 0.1 g additives/g-dry solid, Tween 20 was the most effective additive followed by Tween 80 and BSA. With the addition of Tween 20 mixed with cellulase loading of 15 FPU/g-cellulose, the cellulose conversion increased 14% (from 75% to 89%), which was similar to that with cellulase loading of 30 FPU/g-cellulose and without an additive addition. The results of cellulase and BSA adsorption on the Avicel PH101, pretreated CWR and lignaceous residue of pretreated CWR support the theory that the primary mechanism behind the additives is prevention of nonproductive adsorption of enzymes on lignaceous material of pretreated CWR. The addition of additives could be a promising technology to improve the enzymatic hydrolysis by reducing the enzyme activity loss due to nonproductive adsorption.