Alkali pretreated of wheat straw and its enzymatic hydrolysis

Abstract

The efficiency of enzymatic hydrolysis of cellulose can be improved by various pretreatments of the substrate. In order to increase the efficiency of enzymatic saccharification of the wheat straw, we determined the effect of different pretreatments on the physical structure, chemical components and enzymatic saccharification of wheat straw. Our results showed that combination of grinding and sodium hydroxide (NaOH) treatment had high effect on the enzymatic hydrolysis of wheat straws. The optimal pretreatment condition was to grind the wheat straws into the sizes of 120 meshes followed by treatment with 1.0% NaOH for 1.5 h (121°C/15psi). Under this condition, the cellulose content of wheat straw was increased by 44.52%, while the content of hemicellulose and lignin was decreased by 44.15% and 42.52%, respectively. Scanning Electronic Microscopy and infrared spectrum analyses showed that significant changes occurred in the structure of wheat straws after pretreatment, which is favorable for the hydrolysis and saccharification. Cellulase produced by Penicillium waksmanii F10–2 was used to hydrolyze the pretreated wheat straw and the optimal condition was determined to be 30 h of enzymatic reaction under the temperature of 55°C, pH 5.5 and substrate concentration of 3%.

Statistical Modeling and Optimization of Enzymatic Pretreatment of Empty Fruit Bunches with Laccase Enzyme

“…There is no current record of work done on the effect of substrate concentration on the rate of enzymatic pretreatment of biomass. Similar works on enzymatic saccharification of biomass reported by Han et al (2012) showed that enzyme reactions are retarded when the concentration of substrate for an enzyme medium is exceeded, leading to a reduction in the product and accumulation of the substrate. Total sugar (mg/ml) % weight loss…”

Production of ethanol from wheat straw

“…The problem could be addressed by using a yeast growth medium, which would enhance the viability of yeast cells and increase ethanol yield per g of wheat straw. 50 , the effi ciency of enzymatic hydrolysis of cellulosic biomass can be increased by grinding and pretreating raw material under alkaline conditions. In the cited studies, the effi ciency of enzymatic hydrolysis increased with a rise in NaOH concentrations, and the highest content of reducing sugars was noted at 1% NaOH.…”

Optimization of Pretreatment and Alkaline Cooking of Wheat Straw on its Pulpability Using Response Surface Methodology

“…Appropriately, increasing alkaline concentration was conducive to the dissolution of hemicellulose and low polymerization of cellulose, and also to the swelling of cellulose (Wu et al 2010). However, using an excessive dosage of NaOH and Na2S could cause a serious degradation of the raw materials (Han et al 2012). The dissolution rate of C-5 was significantly higher than that of C-1.…”