title: Enzymatic degradation of model cellulose films.
abstract: Enzymatic degradation of model cellulose films prepared by a spin-coating technique was investigated by ellipsometry. The cellulose films were prior to degradation characterized by ellipsometry, contact angle measurements, ESCA (electron spectroscopy for chemical analysis) and AFM (atomic force microscopy). At enzyme addition to preformed cellulose films an initial adsorption was observed, which was followed by a total interfacial mass decrease due to enzymatic degradation of the cellulose films. The degradation rate was found to be constant during an extended time of hours, whereafter the degradation leveled off. In parallel to the decreased interfacial mass, the cellulose degradation resulted in a thinner and more dilute interfacial film. At long degradation times, however, there was an expansion of the cellulose film. The enzyme concentration affected the degradation rate significantly, with a faster degradation at a higher enzyme concentration. The effects of pH, temperature, ionic strength and stirring rate in the cuvette were also investigated.
authors.affiliation: Institute for Surface Chemistry, Box 5607, SE-114 86 Stockholm, Sweden. jonny.olaspers@bredband.net
authors.forename: Jonny
authors.initials: J
authors.lastname: Eriksson
authors.forename: Martin
authors.initials: M
authors.lastname: Malmsten
authors.forename: Fredrik
authors.initials: F
authors.lastname: Tiberg
authors.forename: Thomas Hønger
authors.initials: TH
authors.lastname: Callisen
authors.forename: Ture
authors.initials: T
authors.lastname: Damhus
authors.forename: Katja S
authors.initials: KS
authors.lastname: Johansen
mesh_terms: D000327:Adsorption; D002384:Catalysis; D044602:Cellulases / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D018625:Microscopy, Atomic Force; D009994:Osmolar Concentration; D012031:Refractometry; D013499:Surface Properties; D013500:Surface Tension; D013696:Temperature
chemical_list: D002482:Cellulose; D044602:Cellulases