Possibilities for recycling cellulases after use in cotton processing
type: CreativeWork
description: Repeated treatments on cotton fabrics, using a total cellulase from Trichoderma reesei, showed that active enzymes remained in the treatment liquor and adsorbed on the fabric substrates after five treatment cycles. The activity (measured as fabric weight loss) of the cellulases remaining in solution, however, decreased by 80% over the five cycles. It was suggested that this could be due to end-product inhibition, thermal and or mechanical deactivation, or to the loss of some components of the cellulase complex by preferential and irreversible adsorption to the cotton substrates. End-product inhibition studies showed that the build-up of cellobiose and glucose in solution would cause less than 25% activity loss after five treatment cycles. Agitation levels similar to those used in textile processing did not cause significant cellulase deactivation, but incubation of total cellulase solutions for 5h at 50 °C (equivalent to five treatment cycles) reduced their activity by about 20%. Analysis of cellulase solutions, by fast protein liquid chromatography, before and after adsorption onto cotton, suggested that the cellobiohydrolase II content of the cellulase complex was reduced, relative to the other components, by preferential adsorption. This would lead to a marked reduction in activity in the supernatant after several treatment cycles and top-up with pure cellobiohydrolase II would be necessary unless this component is easily recoverable from the treated fabric. Although desorption studies showed that much of the adsorbed cellulase protein was recoverable by washing in buffer solution, concentration of the washings by ultrafiltration needs to be carefully costed. Experiments with pure endoglucanases, with and without their cellulose binding domains, suggested that desired cotton finishing effects might be achievable using only cellulase components that are adsorbed reversibly. These would be ideal for recycling. Ultrafiltration was used successfully to reduce end-pro…
abstract: Repeated treatments on cotton fabrics, using a total cellulase from Trichoderma reesei, showed that active enzymes remained in the treatment liquor and adsorbed on the fabric substrates after five treatment cycles. The activity (measured as fabric weight loss) of the cellulases remaining in solution, however, decreased by 80% over the five cycles. It was suggested that this could be due to end-product inhibition, thermal and or mechanical deactivation, or to the loss of some components of the cellulase complex by preferential and irreversible adsorption to the cotton substrates. End-product inhibition studies showed that the build-up of cellobiose and glucose in solution would cause less than 25% activity loss after five treatment cycles. Agitation levels similar to those used in textile processing did not cause significant cellulase deactivation, but incubation of total cellulase solutions for 5h at 50 °C (equivalent to five treatment cycles) reduced their activity by about 20%. Analysis of cellulase solutions, by fast protein liquid chromatography, before and after adsorption onto cotton, suggested that the cellobiohydrolase II content of the cellulase complex was reduced, relative to the other components, by preferential adsorption. This would lead to a marked reduction in activity in the supernatant after several treatment cycles and top-up with pure cellobiohydrolase II would be necessary unless this component is easily recoverable from the treated fabric. Although desorption studies showed that much of the adsorbed cellulase protein was recoverable by washing in buffer solution, concentration of the washings by ultrafiltration needs to be carefully costed. Experiments with pure endoglucanases, with and without their cellulose binding domains, suggested that desired cotton finishing effects might be achievable using only cellulase components that are adsorbed reversibly. These would be ideal for recycling. Ultrafiltration was used successfully to reduce end-pro…
author: Sousa Sepulveda Azevedo, Helena Paula de
license: https://dora.dmu.ac.uk/bitstreams/d81b0251-0897-4798-9bab-3c67a8f640ff/download
date published: 2001-01
date modified: 2026-07-24T06:18:42Z
provider: De Montfort University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: De Montfort University