Epygen Biotech Industries
Often industrial cellulases used in textile processing are random multi-component enzyme systems containing variety of different activities, many of which could be redundant for a particular application. Epygen scientists have initiated enzyme protein research paired with study of properties and morphology of textile fibre to identify the best synergy responsible for Efficient Fuzz Removal in cotton knitted single jersey scoured and peroxide bleached fabric.
It is believed that, in a typical bio-finishing application, while enzyme reaction proceeds on the fibre, intensive mechanical contact, generated by the equipment (a Jet Dyer or Soft Flow machine) results in breaking off the fibre ends, already weakened by enzyme treatment. At uncontrolled enzyme hydrolysis, significant weight and strength losses can occur, surpassing the benefits of the desired finish. To study this balance, multicomponent acid cellulases are compared against monocomponent and endo-enriched cellulase on cotton single jersey knitted fabric in Pilot scale soft over-flow machine. Enzyme dosage were ascertained on equivalent standards of specific cellulase activities.
CELLULOSE in cotton consists of crystalline fibrils which vary in its complexity and length, which are connected by less organized amorphous regions with an average ratio of about two-thirds crystalline and one-third non-crystalline material. Structurally the crystalline cellulose can occur in different lattice types, namely cellulose I, cellulose II, cellulose III and cellulose IV or cellulose X, amongst which only cellulose I and cellulose II are of relevance to textile processing.
Though DP (Degree of Polymerization) of cotton may be as high as 14,000, but it can be reduced to 1,000 2,000 through purification treatments. Crystalline regions reportedly have a DP of 200 to 300, whereas the molecular weight of cotton can range between 50,000 to 150,000.
Structurally, individual polysaccharide chains adhere to each other along lengths by hydrogen bonding and Vander Waals forces. The physical properties of the cotton fibre as a textile material, as well as its chemical behaviour and reactivity, are determined by arrangements of the cellulose molecules with respect to each other, to the fibre axis and their accessibility.
Naturally, wood degrading fungal and bacterial cellulolytic
(whole) enzymes consist of several enzymes acting at the ends (exoglucanases, also called
cellobiohydrolases) or in the middle (endoglucanases) of the cellulose chains.
Trichoderma reesei is one of the highly exploited strains for cellulase
production, whose cellulolytic enzymes are supposed to be primarily composed
of two cellobiohydrolases (CBHI and CBHII) and at least six endoglucanases
(EGI, EGIl, EGIII, EGIV, EGV and EGVI) and two - glucosidases.
It is known that, while the endoglucanases mainly hydrolyse internal bonds in the cellulose polymer producing new chain ends and thereby causing a considerable decrease in cellulose DP, Exoglucanases initiate the hydrolysis at the chain ends, and do not produce significant amounts of new chain ends on the cellulose surface. While CBHII splits cellobiose from the non-reducing and CBH I from the reducing ends of the cellulose chain, Cellobiohydrolases can also act on crystalline cellulose without the aid of endoglucanases. -glucosidases complete the hydrolysis process by catalyzing the hydrolysis of cellobiose to glucose. However, through several experiments, scientists have realised that an efficient overall hydrolysis of crystalline cellulose can only be obtained by a synergistic action of both EGs and CBHs. The challenge had been to identify the right mix of enzymes to obtain the textile effects one is looking for.