LEVANASES FOR CONTROL OF SLIME IN PAPER-MANUFACTURE

Formation of slime deposits is a major problem facing paper industries . The slime may be biological or nonbiological. Biological deposits th at are composed of varied microflora along with fibers, fillers and di rt are the most troublesome. Slime producing microbes secrete extracel lular polysaccharides that gum up the process machinery. The specific nature of slime and its formation depend on the mill environment. Corr espondingly, countermeasures vary with the type of slime deposit. Conv entional slime control methods generally employ combinations of biocid es. This leads to effluent toxicity, as well as high processing and tr eatment costs. Therefore, alternative control measures are in demand. Once such measure is the use of enzymes (levanases) that dissolve the slime to some degree and improve biocide penetration into the slime la yer. As a result, the amount of biocide required is reduced, process e conomics improve and effluent treatment is simplified. (C) 1998 Elsevi er Science Inc.