Enzymatic hydrolysis of cellulose: Evaluation of cellulase culture filtrates under use conditions

Abstract

SummaryCulture filtrates from three mutant strains of Trichoderma reesei grown on lactose and on cellulose were compared under use conditions on four cellulose substrates. Cellulose culture filtrates contained five to six times as much cellulase as lactose culture filtrates. Unconcentrated cellulose culture filtrates produced up to 10% sugar solutions from 1570 cellulose in 24 h. Specific activity in enzyme assays and efficiency in saccharification tests were low for enzymes from all the mutants. Over a wide range the percent saccharification of a substrate in a given time was directly proportional to the logarithm of the ratio of initial concentrations of enzyme and substrate. As a result of this, dilute enzyme is more efficient than concentrated enzyme, but if high sugar concentrations are desired, very large quantities of enzyme are required. Since the slopes of these plots varied, the relative activity of cellulase on different substrates may be affected by enzyme concentration.

Enhancing the Enzymatic Hydrolysis of Corn Stover by an Integrated Wet-milling and Alkali Pretreatment

“…Reducing sugars contained in the supernatant were analyzed with the 3,5-dinitrosalicylic acid method [15] and expressed by dextrose equivalent. Reducing-sugar yield, Y r (%), was defined as follows:…”

Isolation of a Cellulolytic Enzyme Producing Microorganism, Culture Conditions and Some Properties of the Enzymes

“…Table V also compares the typical contents of these cellulase components produced by strain Y-94 with those of the cellulase components produced by Trichoderma reesei QM 9414. 24 ) As can be see!1 in Table V, the composition ratio of FPase : CMCase :{J-glucosidase of the cellulolytic enzyme system produced by strain Y-94 was 1 : 16: 5, while in the case of the enzyme system produced by Trichoderma reesei QM 9414, the aforementioned ratio was 1 : 18 : 0.06. These results indicate that the enzyme system produced by strain Y-94 has a notably high fJ-glucosidase content.…”

Seasonal variation of microbial populations and biomass in Tatachia grassland soils of Taiwan

“…Fungi were grown at 25°C for 5 days on Rose Bengal medium at pH 6.8 ± 0.1 (Yang et al 1998a). Cellulolytic microbes were assayed at 25°C after 7 days incubation on Mandels-Reese medium with carboxymethylcellulose (CMC, Sigma) as the sole carbon source and sprayed with Congo red to show a clear zone around the colonies (Mandels et al 1981). Phosphate-solubilizing microbes were counted at 25°C after 5 days on rock phosphate medium at pH 6.6 ± 0.1 by the clear zone around the colonies (Chang et al 2001).…”