Enzymes paper industry

Technetium carbonyl, 16 66 Technical art history, 11 398 Technical Association of the Pulp and Paper Industry (TAPPI), 21 17 Technical enzymes, 10 310 Technical-grade active ingredient analysis, 18 544... 

The most promising new approaches to using enzymes in the pulp and paper industry, however, are based either on the idea of selected hydrolysis of certain components or limited hydrolysis of several components in the fibre. This concept is apparently in accord with both the technical and economic demands of a feasible process. By limiting the extent of hydrolysis... 

No doubt the cost of xylanolytic enzymes will be one of the factors determining their application in the pulp and paper industry as well as in other areas. Economically feasible xylanase production can be achieved in paper mills employing xylanase-positive transformants of common industrially used microorganisms that are capable of utilizing inexpensive carbon sources originating there. A substantial improvement in the production of xylanolytic systems can be expeaed from mutants of non-cellulolytic microorganisms that are resistant to catabolic repression. Such mutants usually exhibit hyperproduction of extracellular enzymes. 

Industrial and applied multi-step reaction processes, where oxidizing enzymes are components of industrial processes, include in the pulp and paper industry, in the food and beverage industry, for bioremediation, in biosensors and, more recently, in biofuel cells (discussed in more detail in Section 3.8). 

As enzymatic oxidative transformation of the PVA polymer can act as a multiple simultaneous event on the polymer with concurrent chain fission by the appropriate enzymes, the polymer can be broken down into small oligomers that can be channelled into the primary metabolism. This picture is not complete because PVA is usually more or less acetylated. The DH is a pivotal factor in almost every aspect of PVA application. Surprisingly there are very few data dealing with the enzymes involved in the deacetylation of not fuUy hydrolysed PVA polymer. In technical processes, esterase enzymes are widely applied to deal with PVAc structures. A good example is from the pulp and paper industry [85], where PVAc, a component of stickies , is hydrolysed to the less sticky PVA. Esterases from natural sources are known to accept the acetyl residues on the polymer as substrate but little detailed knowledge exists about the identity of acetyl esterases in the PVA degradative environment [86]. 

Skals PB, Krabek A, Nielsen PH, Wenzel H (2008) Environmental assessment of enzyme assisted processing in pulp and paper industry. Int J LCA 13 124-132... 

Enzymes in the Pulp and Paper Industry Bleaching of Pulp with Xylanases or Laccases 145... 

The pulp and paper industry is very capital-intensive with small profit margins. A paper mill can easily cost more than or 1 billion. It must meet increasing demands for pulp and paper and, at the same time, comply with increasingly stringent environmental regulations. Driven by market and environmental demands for fewer chlorinated products and by-products, the pulp and paper industry is one of the fastest-growing markets for industrial enzymes. 

Enzymes such as "cellulases" and a-amylases are currently used by several industries to hydrolyze cellulose or starch to products such as dex-trins, syrups, and sugars. Such reactions represent the key first step toward the production of a variety of useful chemicals and sweeteners and are also useful in the pulp and paper industry for fiber modification and de-inking. 

Forss K, Jokinen J, Savolainen M, Williamson H. Utilization of enzymes for effluent treatment in the pulp and paper industry. Tappi 1983 179-183. 

Hakulinen R. The use of enzymes for wastewater treatment in the pulp and paper industry—a new possibility. Water Sci Technol 1988 20(1) 251-262. 

Enzymes such as a-amylase and (3-amylase can break the starch chains into maltodextrins and starch sugars such as glucose and maltose. The heat-stable enzymes convert the starch after dissolving the starch by jet-cooking. Enzymatically converted starches are used in the food industry (confectionery, baking products, sweeteners), paper industry (surface sizing) and the fermentation industry. 

This review has shown that most studies on barley starches have been focused on understanding the fine structures, particle size distribution, chemical composition, gelatinization properties and susceptibility towards enzyme hydrolysis. However, there is a dearth of information on the rheological and retrogradation characteristics of barley starches from different cultivars. Furthermore, the response of small and large barley starch granules towards physical and chemical modification needs investigation. Research in the above areas is underway in our laboratories. It is hoped that this study may improve the utilization of different types of barley starches for specific products within the food and paper industry. 

The food, feed, and paper industries use hemicellulase to convert hemicellulose to useful products (Wong and Saddler, 1993). At the concentrations found in vegetable waste matter, hemicellulose has been viewed intermit-tendy as a potential enzyme substrate and as feedstock for commercial ethanol and furfural production. 

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