Microbial production of enzymes

Cellulase production A case studyA cellulosic enzyme system consists of three major components: endo--glucanase (EC 3.2.1.4), scission of cellulose chains -Yields glucose and cello-oligo saccharides. exo--glucanase (EC 3.2.1.91) and exo-attack on the non-reducing end of cellulase Yields cellobiose -glucosidase (EC 3.2.1.21).hydrolysis of cellobiose to glucose.

Schematic representation of sequential stages in cellulolysis

large number of microorganisms are capable of degrading cellulosesignificant quantities of cell-free enzymes Fungi - main cellulase-producing microorganisms Trichoderma and Aspergillus - high cellulase producers Trichoderma reesei QM-9414 - was selected as the best cellulase-producing strain - subjected to mono-colony isolation -strain KY-746 A plate screening system -the isolation and evaluation of mutants -for producing high titer cellulase UV and nitrosoguanidine (NTG) treatment A strain free from catabolite repression - was induced using a culture medium - glycerol and glucose, high titer strain was induced - L-sorbose to the medium.

Clearing zones formed by T. reesei mutants on Walseth's Cellulose Agar Plates

Genealogy of artificial mutants of Trichoderma reesei

Representative mutants derived from KY-746 were batch cultured in a 5-L fermentor.evaluation of carbon source utilization -increase in the concentration of Avicel - 6% in batch culture semi-batch culturing -initial Avicel concentration of 6%, followed by subsequent addition of 4% Avicel optimize the stirring rate, aeration volume, feed change, seed volume, and the seed culture period

Effect of initial substrate concentration on cellulase production by batch fermentation

Time course of cellulase production by T. reesei KDG-3 in a 1kL tank

Effect of alkali concentration of the production of cellulase from biomass

Cellulase fermentation was conducted with high-titer enzyme-producing strain CDU-11 under semi-batch conditions in a 4-L fermentor, using inexpensive carbon and nitrogen sources and the pH-shift system. This resulted in the production of CMCase activity exceeding 600 U/ml