Microwave Assisted Enzymatic Hydrolysis of Corn Stalks for L-Lactic Acid Production
Glucose production from pretreated corn stalks by cellulose enzymatic hydrolysis with cellulase was investigated and compared with no pretreatment, as a reference. The corn stalks were pretreated with microwave, sulfuric acid hydrolysis and dilute sodium hydroxide solution hydrolysis respectively. The enzymatic hydrolysis experiments were carried out at 50°C, 50 g/l dry matter (DM) solid substrate concentration and 15 filter paper unit (IU)/g DM of a commercial cellulase. Fermentable sugar was able to be produced from all the pretreated corn stalks with an overall yield of 29-58% of the maximum theoretical yield, based on the glucan available in the solid and liquid substrate. The corn stalks pretreated with dilute acid had the best glucose yield as 58.09% followed by the corn stalks pretreated with acid and microwave with an overall yield of 57.02% with 15 IU/g DM of cellulase. Glucose was the main product with enzymatic hydrolysis yield ratio 38.89%in the dilute sulfuric acid pretreated corn stalks, while with enzymatic hydrolysis yield ratio 51.07%in the dilute sodium hydroxide solution and microwave pretreated corn stalks under enzymatic hydrolysis conditions. These advantages, along with their negative price, make these solids a valuable raw material for L-lactic acid production.
Zhenyu Du and X.B Sun
X. X. Yang and G. Z. Fang, "Microwave Assisted Enzymatic Hydrolysis of Corn Stalks for L-Lactic Acid Production", Advanced Materials Research, Vols. 113-116, pp. 712-715, 2010