Enzyme exhibiting cellulase activity

Chemistry: molecular biology and microbiology – Enzyme – proenzyme; compositions thereof; process for... – Hydrolase

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

435 691, 43525231, 4353201, 435263, 536 232, 25217412, 935 14, 935 29, 935 74, C12N 942, C12N 1556, C12S 1100, C11D 3386

Patent

active

059167963

DESCRIPTION:

BRIEF SUMMARY
FIELD OF THE INVENTION

The present invention relates to an enzyme exhibiting cellulase activity, a DNA construct encoding the enzyme, a cellulolytic agent comprising the enzyme and a detergent composition containing the enzyme.


BACKGROUND OF THE INVENTION

Biomass which largely consists of cellulose, hemicellulose and lignin has attracted increasing attention as an important renewable source of energy (including nutritional energy). The amount of carbon fixed by photosynthesis has been estimated to be 100.times.10.sup.9 tons per year worldwide, and half of that is contained in cellulose. If this material, or at least a significant part of it, could be converted into liquid fuel, gas and feed protein, this would constitute a significant contribution to solving the problem of recycling and conservation of resources. However, it has been found difficult to develop an economically viable process of converting cellulosic material into fermentable sugars.
The currently most promising of the suggested processes involves the use of enzymes which are able to degrade cellulose. These enzymes which are collectively known as cellulases are produced by a number of microorganisms, including fungi (e.g. Trichoderma reseei, Humicola insolens, Fusarium oxysporum, etc.) and bacteria (e.g. Clostridium thermocellum, Cellulomonas spp., Thermonospora spp., Bacterioides spp., Microbispora bispora, etc.). The economics of the production of fermentable sugars from biomass by means of such enzymes is not yet competitive with, for instance, the production of glucose from starch by means of .alpha.-amylase due to the ineffeciency of the cellulase enzymes. The most significant problems connected with the use of cellulases is their low specific activity and the high cost of their production. Therefore, there is a need to develop cellulases which are more efficient in degrading cellulosic materials into fermentable sugars.
Apart from their utility for the degradation of biomass, cellulases have also been suggested for use in detergent compositions for the treatment of cotton-containing fabrics which largely consist of cellulose. It is well known that repeated washing of cotton-containing fabrics generally causes a pronounced, unpleasant harshness in the fabric due to the presence of amorphous regions in the cellulose fibres, which regions form protruding parts on the otherwise smooth fibres. Several methods for overcoming this problem have previously been suggested. For example, U.S. Pat. No. 1,368,599 of Unilever Ltd. teaches the use of cellulases for reducing the harshness of cotton-containing fabrics. Also, U.S. Pat. No. 4,435,307 (of Novo Industri A/S) teaches the use of a cellulytic enzyme derived from Humicola insolens as well as a fraction thereof as a harshness reducing detergent additive. Other uses of cellulases mentioned in the art include soil removal frown and colour clarification of fabric (cf. for instance EP 220 016).
Although the use of cellulase enzymes for harshness reduction of cotton-containing fabrics was suggested and demonstrated nearly 20 years ago the mechanism of this process has not been elucidated and is still not known in detail. Among other things, this is due to the multiplicity of the enzymes and the enzyme-catalyzed reactions involved. As a matter of fact, cellulases generated in nature e.g. by microbial species are indeed complex mixtures of cellulases. Accordingly, the conversion of naturally occurring materials, like cotton, catalyzed by cellulases is exceedingly difficult to analyze in detail.
Due to these circumstances, the practical exploitation of cellulases for harshness reduction and prevention as well as colour clarification, however desirable, has not become widespread and of great practical utility: it is difficult to optimize production of multiple enzyme systems and thus to implement industrial cost-effective production of cellulase enzymes, and their actual use has been hampered by difficulties arising from the need to employ rather large quantities of the cellulases to achieve the des

REFERENCES:
patent: 4443355 (1984-04-01), Murata et al.
patent: 4652639 (1987-03-01), Stabinsky
patent: 4822516 (1989-04-01), Suzuki et al.
patent: 5006126 (1991-04-01), Olsen et al.
patent: 5010000 (1991-04-01), Palva
Fortkamp, E., et al., DNA, vol. 5, "Cloning and expression in Escherichia coli of a synthetic DNA for hirudin, the blood coagulation inhibitor in the leech", pp. 511-517, 1986.
Warren et al., Chem. Abs., vol. 108, No. 19, p. 295, abs. No. 163739k (1988).
Greenwood et al., Chem. Abs., vol. 110, No. 23, abs. No. 208834x (1989).
Kilburn et al., Chem. Abs., vol. 111, No. 19, p. 331, abs. No. 170011g (1989).
Ong et al., Chem. Abs., vol. 111, No. 21, p. 619, abs. No. 192974a (1989).
Borriss, R., et al., Carlsberg Research Communications, vol. 54, No. 2, pp. 41-54, 1989.
Fukumori, F., et al., Journal of General Microbiology, vol. 131, Part 12, pp. 3339-3345, Dec., 1985.
MacKay, R.M., et al., Nucleic Acids Research, vol. 14, No. 22, pp. 9159-9170, 1986.
Park, S.H., et al., Agricultural and Biological Chemistry, vol. 55, No. 2, pp. 441-448, Feb., 1991.
Kim, J-M, et al., Applied and Environmental Microbiology, vol. 53, No. 11, pp. 2656-2659, Nov., 1987.
Hansen, C.K., et al., Journal of Bacteriology, vol. 174, No. 11, pp. 3522-3531, Jun., 1992.
J.o slashed.orgensen, P.L., et al., Gene, vol. 93, pp. 55-60, Sep., 1990.
Ong, E., et al., Tibtech, vol. 7, pp. 239-243, Sep., 1989.
Zayre et al. 1988. Applied and Environmental Microbiology 54 (5) : 1289-1292.
Van der Plas et al. 1989. Moleculer Microbiology 3(3) : 275-284.
Suggs et al. 1981. Proc. Natl. Acad. Sci., USA, 78(11) : 6613-6617.
Nakamura. 1984. Int. J. Syst. Bacteriol. 34 (2) : 224-226.
Saul et al. 1989. Nucleic Acid Res. 17 (1) : 439.
Beguir et al. 1985. J. Bacteriol. 162 (1) : 102-105.
Hall et al. 1988. Gene 69 : 29-38.
Day, 1983. How to Write and Publish a Scientific Paper, iSi Press, Philadelphia, PA, pp. 15-19.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Enzyme exhibiting cellulase activity does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Enzyme exhibiting cellulase activity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Enzyme exhibiting cellulase activity will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1375126

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.