Production of cellulase and protein from barley straw by Trichoderma viride

Abstract

SummaryThe cellulase production by two strains of the cellulolytic fungus Trichoderma uiride was examined. The fungi were grown on different preparations of barley straw pretreated with NaOH under high pressure. The production of cellulases and microbial protein by the better strain (QM 9123) was investigated in an aerated bliter fermenter under varying stirring rates (200-350 rpm) and straw concentrations (1-2%). The pH was kept between 3.5 and 4.5. The growth of the fungus was followed by measuring the quantity of COt produced and the cell protein. After 2-6 days growth ceased, the lag phases lasting 0-2 days, increasing with increasing straw concentrations. The maximum enzyme yields were reached after 4-10 days. The protein content of the product was 21-26% and up to 70% of the straw was utilized. The yield constants were calculated to be 0.40-0.56; of the same order as those which can be obtained by growing the fungus on glucose.

Continuous cultivation of Trichoderma viride on cellulose

“…This compares favorably with the productivity obtained in batch fermentations, 8 X pg/ml * hr for 9. 4 and 27 g/liter cellulose, re~pectively.~ However, the cellulase activity in the harvest stream from the continuous fermentation is only 10-30'% of what is obtained in a batch fermentation under similar conditions, and so to be used in an industrial process the cellulase solution would have to be concentrated. …”

Cellulase and β-glucosidase production by a basidiomycete species

“…It could also be possible that FPA enzyme(s) are adsorbed on the nonutilized cellulose to a greater extent than CMCase is and are therefore detected later. With T. \piride; on the other hand, Peitersen (1975) and Mandels and Weber (1969) reported that C, (CMCase) enzymes are produced later than the C, enzymes (FPA). The patterns of CMCase, FPA, and P-glucosidase production during the growth cycle were similar ( Fig.…”

“…It has been reported that glucose in amounts up to 0.1% has a markedly positive effect on FPA (Peitersen 1975) and CMCase (Gretna 1970). Mandels and Weber (1969) have also recommended the addition of small amounts of glucose to Trichodermn cultures to support initial growth.…”

Fermentative Production of Pyruvic Acid from Citrus Peel Extract byDebaryomyces coudertii

“…Increasing concern about the environmental problems and the food and feed shortages have stimulated interest in converting these agricultural wastes to commercially valuable products. At present, barley straw 2 ) and sugar cane bagasses 3 ) have been used as microbial substrates.…”