Method for preparing high-temperature-resistant alkaline xylanase

Abstract

The invention discloses a method for preparing high-temperature-resistant alkaline xylanase, belonging to the technical field of preparation of enzyme preparations. Bacillus thermophilus 701 capable of producing high-temperature alkaline xylanase is taken as a starting strain, and high-temperature-resistant alkaline xylanase, which has strong high-temperature resistance and alkali resistance, wide acting conditions, no cellulase activity and is suitable for the fields such as papermaking, food and feed, is prepared by optimizing the culture medium composition and fermentation process in a way of liquid submerged fermentation. The specific activity of the enzyme is 350-420IU / ml; the optimal reaction temperature is 65 DEG C, the application temperature range is 40-75 DEG C; the optimal reaction pH value is 10.0 and the pH range applicable to reaction is 5.0 to 11.0.

Description

technical field [0001] The invention belongs to the technical field of enzyme preparation, in particular to a preparation method of high temperature resistant alkaline xylanase. Background technique [0002] Cellulose, hemicellulose and lignin are the main components of plant hemicellulose. They work together to form the supporting framework of plant cell walls. Among the three, hemicellulose accounts for more than 35% of the dry weight of plants. Hemicellulose It is also a general term for a variety of complex glycans, and its main component is xylan, which is a complex poly-five-carbon sugar. The main chain of xylan is connected by multiple xylopyranosyl groups through β-1-4 glycosidic bonds, and different substituents are connected to the side chains, such as acetyl group, glucuronyl group, L-arabinosyl group etc. (Collins et al., 2005). Therefore, the complete degradation of xylan requires the participation of various enzymes. Xylans are generally divided into hardwoo...

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Problems solved by technology

[0009] From this point of view, many international and domestic experts, scholars and scientific research staff have spared no expense in money, manpower and time to increase the research and development of high temperature and alkali resistant xylanase, aiming to apply biotechnology to papermaking, food , Feed and other fields to a higher, newer, stronger new era, whether it is the acquisition of new strains, or the use of genetic recombination technology, although such a large amount of financial resources and energy have been spent, the results are not satisfactory , it is difficult to achieve the research and development goals and requirements of high temperature resistance and alkali resistance xylanase, either temperature resistance is not alkali resistance; or alkali resistance is not temperature resistance; or the range of alkali resistance and high temperature resistance is not wide; And have cellulase activity; or the substrate is not suitable, etc., to prepare a kind of stronger alkali resistance, higher temperature resistance, wide range of alkali resistance and high temperature resistance, no cellulase activity and suitable for papermaking, food and feed, etc. The high temperature resistant alkaline xylanase in the field is still the relentless pursuit and research and development direction of those skilled in the art