The Use of a Trichoderma reesei Culture for the Hydrolysis of Wheat Straw to Obtain Bioethanol

To reduce environmental pollution, a renewable source of energy that we may utilize is bioethanol obtained from wheat straw. Wheat straw was ground to 40–50 mm in size and heat-treated with high-pressure steam to release lignocelluloses, making them accessible to enzymes during saccharification. Through mechanical pretreatment, a substrate was obtained, which contains toxic components in concentrations that do not diminish the performance of the enzymes in the enzymatic hydrolysis phase. Through the thermal pretreatment of wheat straw, its acidity was improved, influencing the amounts of glucose, xylose, and other components emitted. Following enzymatic hydrolysis, very small concentrations of sugars were released. In order to increase the efficiency of the transformation of sugars into ethanol during the fermentation process, a strain of yeast, Trichoderma reesei multiplied in the laboratory, was added, under the conditions of temperature—28 degrees and stirring—800 rpm. Trichoderma reesei penetrated the wheat straw substrate, facilitating the subsequent hydrolysis process. The improved biodegradation of the pretreated straws was highlighted by the electron microscopy analysis.