Among the hundreds of famous enzyme preparation enterprises in the world, NOVO Company in Denmark firmly occupies the leading position, accounting for more than 50% of the market share, followed by Genenco Company, accounting for about 25% of the market share, and the remaining 25% of the market share is shared by enzyme preparation enterprises in other countries.
Enzymes used in industry are basically divided into two categories: one is hydrolase, including amylase, cellulase, protease, lipase, pectinase, lactase and so on. , accounting for more than 75% of market sales. At present, about 60% of enzyme preparations are produced by transgenic strains, and 80% of the strains used by Novartis are recombinant strains. The second category is non-hydrolase, accounting for 65,438+00% of the market sales.
In the food industry, the proportion of enzymes used in starch processing is still the largest, accounting for15%; Followed by the dairy industry, accounting for 14%. Although the traditional application of enzymes in food, textile and leather industries has been quite extensive and technically mature, it is still developing. The following briefly introduces the production safety of enzymes and the new progress in industrial application in recent years:
Safety and health management of 1 enzyme preparation production
With China's entry into WTO, we must pay attention to the safety and health management of enzyme preparation production. Enzyme preparations for food are used as food additives abroad, and their safety and hygiene regulations are very strict. Although enzyme itself is a biological product, which is safer than chemical products, enzyme preparation is not a simple product. It often contains culture medium residues, inorganic salts, preservatives, diluents, etc. In the production process, it may be contaminated by Salmonella, Staphylococcus aureus and Escherichia coli. In addition, it may contain biotoxins, especially aflatoxin. Even Aspergillus Niger, some strains may produce aflatoxin. Aflatoxin is produced by the strain itself or brought in by raw materials (moldy food raw materials). In addition, inorganic salts should be used in the culture medium. It is inevitable that toxic heavy metals such as mercury, copper, lead and arsenic will be mixed. In order to ensure the absolute safety of products, raw materials, strains, post-treatment and other processes should be strictly controlled. The production site shall meet the requirements of GMP (Good Manufacturing Practices). As for the safety requirements of enzyme preparation products, the Food and Agriculture Organization of the United Nations (FAO), the World Health Organization (WHO) and the FAO/ WHO Expert Committee on Food Additives (J·ECFA) put forward the evaluation criteria for the safety of enzyme preparation sources as early as the 2nd 1978 meeting of WHO:
(1) Enzymes produced by edible parts of animals and plants and strains traditionally used as food ingredients or used in food can be regarded as food without toxicity test if they meet the corresponding chemical and microbiological requirements.
(2) The enzymes produced by non-pathogenic general food contaminated microorganisms need to be tested for short-term toxicity.
(3) Extensive toxicity tests should be conducted on enzymes produced by rare microorganisms, including long-term feeding tests on mice.
This standard provides a basis for the safety evaluation of enzyme preparation production in various countries. Production strains must be non-pathogenic, do not produce toxins, antibiotics and hormones, and the strains must be proved harmless through various safety tests before they can be used for production. For the determination of toxins, besides chemical analysis, biological analysis is also needed. In Britain, the safety of additives is decided by the Chemical Toxicity Committee.
COT, and make recommendations to the government expert advisory Committee (food additives and pollution Committee). COT is most concerned about the toxicity of the strain, and it is suggested that microbial enzymes should be fed to rats for at least 90 days for high-standard biological analysis. COT thinks it is necessary to improve the strain, but biological tests should be carried out after each improvement. There are two kinds of enzyme preparation management systems in the United States: one is in line with GRAS (generally considered to be safe). Second, it meets the requirements of food additives. Enzymes regarded as GRAS substances can be produced as long as they meet GMP requirements. Enzymes considered as food additives must be approved before marketing and registered in CFR (Federal Regulations). To apply for GRAS, you must pass two main assessments. That is, the acceptance evaluation of technical safety and product safety test results. GRAS certification can be independently conducted by any expert qualified to evaluate the safety of food ingredients, except FDA. Animal raw materials for producing food enzymes in the United States must meet the requirements of meat inspection and carry out GMP production, while plant raw materials or microbial culture medium components enter food residues under normal use conditions. It must not be harmful to health. Equipment, diluents, additives, etc. Use should be suitable for food. Production methods and culture conditions should be strictly controlled so that the producing bacteria will not become a source of toxins and harmful to health.
In addition, in recent years, the world food market has implemented the Jewish food certification system, that is, the food system that meets the requirements of Jewish canon. Only with a Jewish certificate can you enter the market of Jewish organizations in the world. In the United States, not only Jews, but also Muslims, vegetarians and people who are allergic to certain foods, most people also buy Jewish food. According to the regulations, Jewish food must not contain pigs, rabbits, horses, camels, shrimps, shellfish, winged insects and reptiles. Enzymes for processing Jewish food should also meet the requirements of Jewish food. Therefore, many foreign food enzyme preparations are labeled Jewish food. We must pay attention to this if we want to develop enzyme preparations overseas. Compliance with Jewish food requirements is reviewed and approved by a specialized agency that is more stringent than the FDA.
2 new uses of enzymes in industry
2. 1 preparation of functional oligosaccharides
In recent 20 years, probiotics with bifidobacteria and lactic acid bacteria as the main components and prebiotics with fructooligosaccharides, isomaltose and galactooligosaccharides as the new generation of health food have been popular all over the world. The annual sales volume of various functional oligosaccharides converted by enzymatic method has exceeded 654.38+10,000 tons. Functional oligosaccharides refer to those oligosaccharides that are indigestible or difficult for human body to digest and absorb, and directly enter the large intestine after ingestion. It is selectively and preferentially utilized by beneficial bacteria (Bifidobacterium, etc.). ), so that Bifidobacterium can multiply and promote the health of the host, so it is also called Bifidobacterium factor. These oligosaccharides are not used by Streptococcus mutans, the pathogenic bacteria of dental caries, and will not cause tooth decay if eaten. Taking 3 ~ 10g functional oligosaccharides every day can improve gastrointestinal function, prevent defecation and mild diarrhea, and reduce the production and absorption of intestinal endotoxin.
(1) isomaltooligosaccharides: indigestible oligosaccharides, which are not decomposed by saliva and pancreatic juice, but can be partially decomposed and absorbed in the small intestine. The calorific value is about 70% ~ 80% of sucrose and maltose, which has little direct stimulation to the intestine. The LD50 of acute toxicity test in mice was above 44g/ kg. Safety is not inferior to sucrose and maltose. The maximum unused dose of human body is 1.5g/kg (the upper limit of no diarrhea for 24 hours after ingestion), while the maximum unused dose of other indigestible oligosaccharides or sugar alcohols is only 0. 1 ~ 0.4g/kg. After ingesting isomaltose, beneficial bacteria such as bifidobacteria and lactic acid bacteria 16g were obvious in the intestine one week later. However, harmful bacteria such as Bacteroides and Clostridium were inhibited, constipation was improved, fecal pH decreased, organic acids increased and corruption decreased. Mouse experiments show that after taking isomaltose, immunity is enhanced and blood lipid is improved. Isomaltose is stable in high temperature, slightly acidic and acidic environment, and can be added to various foods and beverages.
Isomaltooligosaccharide is a syrup made from starch by α-amylase liquefaction, β-amylase saccharification and α-glucosidase transglycosylation, including branched oligosaccharides such as isomaltose, pentose and isomaltotriose, with α- 1 6 bond. There are two kinds of isomaltose on the market, 50% and 90%. The latter is prepared by removing glucose from 50% isomaltose by ion exchange or yeast fermentation.
α -glucosidase producing isomaltose is a by-product of glucoamylase produced by Aspergillus Niger. It is obtained by removing α -glucosidase from saccharifying enzyme fermentation broth by ion exchange adsorption, eluting and concentrating. Although there are many reports about the production of α -glucosidase by Aspergillus Niger, it has not been used in commercial production. Generally, the production of isomaltooligosaccharides from maltose by α -glucosidase is only about 50%. In addition, it also contains 20% ~ 40% maltose and glucose. In order to improve the yield of isomaltooligosaccharides, there have been many research reports. If Aspergillus fumigatus α -glucosidase is used, the yield of panose in the product can reach 30%, and the glucose content can be reduced to 20%. Takasaki found that pullulanase produced by Bacillus stearothermophilus had transglycosylation in the presence of high concentration of maltotriose. Its structural gene was introduced into Bacillus subtilis NA- 1. The new pullulanase and Bacillus subtilis act together on starch to saccharify α -amylase (which can produce maltotriose). The yield of isomaltooligosaccharide can reach 60%, and the glucose content is reduced from 40% to 20%. In order to improve the α -glucosidase activity of Aspergillus Niger, the Department of Bioengineering of Tokyo University introduced the α -glucosidase gene AGLA into Aspergillus Niger GN-3 and obtained the transformant Giz 155.
At present, there are as many as 50-60 enterprises producing isomaltose in China, with a production capacity of over 50,000 tons. The dosage of α -glucosidase is 0. 1%, it needs 50 tons, and the foreign exchange consumption is huge (750,000,375 million yuan per ton). Self-sufficiency is necessary.
(2) Trehalose: It is a non-reducing oligosaccharide formed by connecting two molecules of glucose with α, α- 1. 1 bond. It is widely found in animals, plants and microorganisms (such as bacteria, algae, shrimp, beer yeast and baker's yeast) and is the main blood sugar of insects. Trehalose can protect some animals and plants from dry and frozen environment. Therefore, it has good acid resistance and heat resistance, and is not easy to react with protein and amino acids. It has a strong inhibitory effect on starch aging, protein denaturation and fat oxidation. In addition, it can eliminate the bitterness of some foods and the fishy smell of meat. Trehalose is not used by Streptococcus mutans, so eating it will not cause tooth decay. The survival rate of active dry yeast depends entirely on the trehalose content in yeast cells. In the past, trehalose was extracted from yeast (the highest content was only 20%), and the cost was very high. It is as high as 20,000 to 30,000 yen per kilogram. Now it can be produced by enzyme or fermentation, and the cost is greatly reduced. Kubota et al. found a group of trehalose-producing enzymes (trehalose synthase MTSASE and maltooligosaccharide trehalose hydrolase MTHASE) from soil bacteria such as Arthrobacter, Micrococcus, Flavobacterium and Sulfobacterium. When they act on liquefied starch together with isoamylase, cyclodextrin-producing enzyme, α -amylase and glucoamylase, 85% can be obtained.
(3) The scientific name of palagin is isomaltulose: sucrose is used as raw material. Under the action of α -glucosyltransferase (also known as sucrose invertase sucrose polymerase) from prion bacteria or Serratia Plymouth, the combination of glucose and fructose in sucrose molecules changed from α- 1, 2- bond to α- 1, 6- bond. Due to the change of structure, its sweetness is reduced to 42% of sucrose, its hygroscopicity is low, its stability to acid is increased, its heat resistance is slightly decreased, and its biological and physiological characteristics are changed, so it cannot be used by most bacteria and fungi. After eating, it is not decomposed by enzymes in the mouth and stomach, and can not be hydrolyzed into glucose and fructose by enzymes until the small intestine enters metabolism.
Paladin will be dehydrated and concentrated into 2 ~ 4 molecules of oligomeric paladin at low water content and low pH, and its sweetness is 30% of sucrose, which will not be digested by intestinal digestive enzymes. After eating, it can directly reach the large intestine, and is selectively used by Bifidobacterium, which plays a health care role of Bifidobacterium. Using Ranieri nickel as catalyst, Palagin was oxidized at high temperature and high pressure to produce Palagin alcohol. The sweetness of this sugar alcohol is 45 ~ 60% of sucrose. The calories are half that of sucrose. It is not easy to digest and absorb after eating, and it will not cause the increase of blood sugar and insulin, and it will not cause tooth decay. Suitable for diabetics, the elderly and obese people as sweeteners. Because its physical properties are similar to sucrose, it can be used to make low-calorie candy, which is a new generation of sweeteners popular all over the world. The above three sugars have been produced in large quantities and widely used in Europe, America and Japan. Although it has been successfully studied in China, there are still many obstacles in production and application.
(4) Fructooligosaccharide: It is a mixture of sucrose, sucrose, glucose and fructose, which is formed by connecting 123 fructose molecule with D2 fructose of sucrose molecule through β22, 1 chain under the action of β 2 fructosyltransferase of Aspergillus Niger. Sweetness is 60% of sucrose. After removing glucose and fructose by ion exchange resin, the product containing more than 95% fructooligosaccharides can be obtained, and the sweetness is 30% of sucrose. Sucralose and sucralose, the main components of fructooligosaccharides, are not hydrolyzed by α2 glucosidase in saliva, digestive tract, liver and kidney at all. They are dietary fibers, which can reach the large intestine directly after eating, so they are preferentially used by beneficial bacteria in the large intestine. Eating fructooligosaccharides will not cause an increase in blood sugar and insulin levels. The calorific value is 1. 5 kcal/g. Through the proliferation of Bifidobacterium, the intestinal tract can be purified, the body's immunity can be enhanced, nutrition can be improved, and blood lipid can be reduced. In the experiment of 50-90-year-old people, the number of intestinal bifidobacteria increased from 5% to 25% after 8 days of fructooligosaccharides eclipse. After 4 days, 80% of constipation patients' symptoms were improved.
Fructooligosaccharides also exist in Jerusalem artichoke, chicory and asparagus. Inulin is used as raw material in western Europe and is partially hydrolyzed by inulinase. The Japanese government has approved fructooligosaccharides as a specific health food. Western Europe, Finland, Singapore, Taiwan Province Province and other places use fructooligosaccharides as functional food ingredients, which are widely used in various foods. The annual production capacity of fructooligosaccharides in Chinese mainland is 1 0.5 million tons, that of Guangdong Jiangmen Quantum Technology is10.5 million tons, that of Yunnan Tianyuan is 3,000 tons, that of Zhangjiagang Liangfeng is10.5 million tons, and that of Guangxi University is 500 tons.
(5) Xylo-oligosaccharide is characterized by its strong stability to acid and heat, so it can be used in acidic drinks such as fruit juice. Because it is not used by most intestinal bacteria, only a few bacteria, such as Bifidobacterium, can be used. It is a powerful bifid factor, and it can take effect when ingested 0. 7g per day. This sugar is made from corncob, extracted from its xylan and hydrolyzed by Aspergillus xylanase. It was first produced by Suntory Company of Japan. With the support of China Agricultural University, China Shandong Longli Company successfully developed. Shandong Food Fermentation Research Institute also announced its success. In addition, China has also successfully developed other functional oligosaccharides such as galactooligosaccharides and mannooligosaccharides.
2.2 Enzymes are used to produce functional peptides
In recent years, it has been found that peptides produced by proteolysis have better absorbability than amino acids composed of protein or protein, so they can be used as infusion, athletes' food, health food and so on. In protein hydrolysate, some peptides have physiological activities, such as casein phosphopeptide (CPP) produced by trypsin or alkaline protease hydrolysis. It can promote the absorption of calcium and iron. Hydrolysates obtained by enzymatic hydrolysis of fish, soybean and casein contain amino acids with the sequence of Ala-Val-Pro-Tyr-Pro-Gln-Arg, which is an angiotensin converting enzyme inhibitor (ACEI, an angiotensin converting enzyme inhibitor type 2). It can bind with angiotensin and affect its activity expression, thus preventing blood pressure from rising. It is an ideal antihypertensive health food. Among the peptides with different structures obtained from different protein raw materials and different proteases, some peptides also have physiological functions such as reducing blood fat, promoting alcohol metabolism, resisting fatigue and resisting allergy. It is good for your health to eat fermented foods such as soybean paste, fermented soybean, natto and fermented milk.
But some people put it into capsules and sell it as a health care product, which is very profitable.
2.3 Enzymes used in the oil industry
The application of enzyme in oil industry is still in the primary stage. (1) Cellulase and hemicellulase are used in oil extraction industry: after oil is extracted with solvent, it is difficult to completely remove the residual solvent in the residue, which affects the application of feed. Therefore, Japan has developed a method of decomposing plant tissues with cellulase, hemicellulase and pectinase to extract oil. The method is to crush or heat treat olive and rapeseed, and then add hemicellulase to react for several hours. Centrifugal separation of oil residue. This technology has been used to extract olive oil and orange oil, and rapeseed oil has entered the pilot stage. In the production of animal oil, protein is separated from oil by protease treatment, because high temperature treatment can be avoided and the quality of oil is better. In order to remove residual lecithin from oil, phospholipase was used to remove water-soluble lecithin from oil.
(2) manufacturing fatty acids
Lipases can be divided into position-specific and non-specific, and they are also selective for fatty acid chain length and unsaturation of substrates. Fatty acids were produced by hydrolyzing lard with site-specific lipase, which was used as raw material for making soap. When fish oil is hydrolyzed by lipase which has no effect on unsaturated fatty acid esters, the triglyceride of highly unsaturated fatty acid DHA is difficult to hydrolyze, so it can be used to make omega 3 fatty acids such as DHA.
(3) ester exchange reaction
By changing the fatty acid composition of oil through transesterification of lipase, the properties of oil can be changed, such as modifying palm oil into cocoa butter.
2.4 transglutaminase (TGASE) transglutaminase used in meat processing can catalyze the transacylation reaction between γ2 amino group on glutamic acid residue in protein molecule and various primary amines. When ε2 amino group of lysine residue in protein is used as acyl acceptor, ε2(γ2Gln) Lys *** valence bond can be formed between molecules for crosslinking, which can increase the gel strength of protein and improve the structure and functional properties of protein. Low-value minced meat can be reorganized to improve the appearance and taste of fish and meat products, reduce losses, and thus improve economic value. Essential amino acids, such as methionine and lysine, can also be introduced into protein, which lacks such amino acids, so as to improve the nutritional value. This enzyme can also be used in wool fabric processing, enzyme immobilization or the connection of different molecules, antibodies and drugs. The production strain is S. Reptovertiilli Ummobaracenes which has been commercialized in Japan.
2.5 New application of enzymes in fruit and vegetable processing
Application of (1) protopectinase in pectin extraction;
Pectin in fruit exists in the form of insoluble protopectin before ripening, and gradually changes into soluble pectin during fruit ripening. Protopectin can also become soluble pectin under the action of acid and heat. Protopectinase produced by Bacillus subtilis, Aspergillus niger, yeast and basidiomycetes has been developed to extract pectin from orange peel, apple, grape peel and carrot. Compared with acid-thermal method, enzymatic extraction of pectin has the advantages of simple process, no pollution, low cost and high product quality.
(2) Using impregnated enzyme to improve fruit quality.
Juice yield:
Atherosclerotic enzyme is a mixture of pectinase, hemicellulase (including xylanase, arabinoxylan and mannanase) and cellulase, which acts on broken fruits and has better effect of promoting filtration and improving juice yield than single pectinase. It has become the main enzyme in fruit juice processing.
(3) treating complete fruits and vegetables by vacuum or pressurized enzyme infiltration:
Soaking fruits and vegetables under pressure or vacuum can make pectinase penetrate into cell gaps or cell walls. This method has been used to soften the whole orange, and the orange peel is easy to peel. It is also used to harden peach flesh. Infiltrating pectin methyl esterase and Ca2+ into peach pulp can improve the hardness of canned peach by 4 times (because demethylated pectin can combine with Ca2+ to enhance the hardness). In this way, the pickled vegetables can be prevented from softening and remain brittle. This method is also used to debitterize orange peel with naringinase.
(4) Enzymes are used to remove phenols.
The clarified juice still appears white turbidity after ultrafiltration concentration, which is caused by phenolic compounds in the juice. Therefore, before filtration, it can be treated with seven kinds of enzymes, which can be oxidized and polymerized into insoluble polymers and removed by filtration.
(5) Pectinase is used to clean pectin pollutants in the filter membrane.
(6) β2 glucanase was used to remove β glucan produced by botrytis cinerea infection in grape juice, while lysozyme promoted the precipitation of insoluble substances.
2.6 Application of Enzymes in Textile Industry
With the development of enzyme preparation industry, cellulase, pectinase, xylanase, protease and other enzymes have been adopted by textile industry.
(1) Enzymes for Cotton Finishing
With the popularity of jeans, the textile industry has paid extensive attention to finishing cotton cloth with cellulase to improve the appearance and feel of the fabric. Cellulase acts on the amorphous region of natural fibers, which partially degrades and modifies the fibers, making the fabric soft, smooth and comfortable in hand and appearance. Usually, after enzyme treatment, cotton cloth loses 3-5% in weight, but loses about 20% in fastness. In developed countries, people's pursuit of fashion does not care about the fastness of fabrics.
Catalase is usually used to remove residual H2O2 after H2O2 bleaching. Recently, it has been found that Cladosporium and Coprinus cinerea can produce catalase in large quantities, and catalase is also used in detergents. Pectinase is used in cotton fabric finishing, which mainly decomposes pectin on the surface of cotton and linen fabric and is used for bleaching and dyeing. The enzyme is phenol oxidase. With O as H acceptor, it is mainly used for decolorization of denim indigo dyeing. NOVO Company uses gene technology to increase the output of Aspergillus Niger. Lignin can also be decomposed by seven enzymes. Xylanase can be used to bleach cloth blanks and remove lignin and cottonseed hull from attached fibers.
(2) Anti-felting finishing of wool fabric with protease
Wool fabrics can no longer be worn if they shrink without finishing and washing (for example, inferior sweaters shrink very little after washing), so they must be treated with anti-felting and anti-felting treatment. Anti-felting and anti-corrosion treatment have a history of more than 65,438+000 years. In the past, chlorine gas, H2O2 and persulfate were used for treatment, which caused serious pollution. In 1990s, a chlorine-free shrink-proof agent was developed. Wool structure can be treated with protease to prevent felting. It was studied in the 1940s. In 1960s, Japan reported that papain treatment can prevent felting, and can be used for low-temperature dyeing to improve dye uptake, reduce sewage and improve the feel and impression of wool fabrics. In 1970s, we also tried acid protease treatment for low temperature dyeing, and achieved good results. The dye uptake increased by 3. 6%, the amount of sewage decreased by 62%. The yarn breakage rate per thousand spindles decreased to 145. The tensile strength, tensile strength and hand feel are obviously improved. Since 1980s, the technology of enzymatic anti-felting has attracted the attention at home and abroad again. Japan, Britain, the United States and other countries have published a large number of research articles and made some progress. Proteases studied include pancreatin, papain, alkaline protease, neutral protease and acidic protease. I believe these technologies will mature and popularize soon.
2.7 Application of Enzymes in Paper Industry
Paper industry is an important source of environmental pollution. With the enhancement of people's awareness of environmental protection, the application of biotechnology in paper industry has aroused great interest in various countries. The key is to degrade lignin. Recently, some people in China use various microorganisms to make pulp, and have made gratifying progress. At present, they are preparing to expand their experiments. The application of enzymes in paper industry is mainly lipase for resin removal of logs, and cellulase, hemicellulase and lipase for ink removal after recycling waste newspapers. Xylanase used in pulp bleaching.
(1) Removing resin from logs:
Because the logs used for papermaking contain resin, when pulping and papermaking, the resin pollutes the equipment, which affects the production and reduces the quality of paper products. For this reason, it takes a long time (more than 3 months) to pile up outdoors to decompose resin, which affects the production cycle and occupies a large area. Japanese paper research institutions have studied the composition of logs and found that 96% of the resin components are oleic acid and linoleic acid, which can be removed by lipase treatment. Since it was put into production in 1990s, the quality of paper products has been improved, the cost of log stacking has been reduced, the amount of resin adsorbent has been reduced, and the economic benefits have been improved. The lipase used at that time was provided by NOVO company and worked well at pH 6 ~ 10 and 40 ~ 60℃. Recently, it was found that lipase resistant to 70℃ was more effective.
(2) pulp bleaching:
In order to remove lignin from pigment, pulp must be treated with chlorides such as chlorine, hypochlorous acid and chlorine dioxide, which causes serious pollution. Therefore, in the 1960s, lignin was considered to be decomposed by ligninase. Lignin is a kind of polymer with phenylpropane as the skeleton, which will decompose only after decomposition. Lignin peroxidase (IP), manganese-dependent peroxidase (MNP) and protease (LAC) have been found to have the ability to decompose lignin. But so far, no suitable lignin enzyme has been found. In recent years, Finland has put forward a treatment method combining chemical method and enzymatic method, and achieved good results. Firstly, the relationship between lignin and cellulose (xylan and hemicellulose) is cut off by xylanase, so that lignin is free. Then, after cooking with alkali, the xylan released from the pulp can be adsorbed on the fiber surface again, and decomposed with xylanase, which can increase the porosity, improve the permeability of chlorine and make lignin easily come out of the pulp.
(3) Deinking in waste paper recycling
When recycled waste paper is used for pulping, alkali, nonionic surfactant, sodium silicate and H2O2 are needed for deinking. In Japan, adding alkaline cellulase and hemicellulase to react for 2 hours can improve the whiteness of paper by 4-5%, but the strength does not decrease. In order to prevent printing ink from getting dirty, advanced triglycerides, such as linoleic acid, linolenic acid and oleic acid, were added to the ink, so lipase was added to achieve deinking effect.
2. Other 8 people
Phytase is not only used as feed additive to improve the utilization rate of organophosphorus in feed, reduce the pollution of phosphorus in feces to the environment and save the amount of phosphate in feed. In recent years, phytase has also been used in brewing to improve the utilization rate of phosphorus in raw materials, and to produce potassium-removed soybean protein food, which has become a source of protein for patients with kidney disease. α-Glucosyltransferase is also used in stevia processing. It is used to remove bitterness and astringency. Liquefaction and saccharification of starch account for almost the majority of industrial enzymatic reactions. Because the current enzymatic liquefaction and saccharification are carried out at different pH values and temperatures, it is necessary to develop acid-resistant high-temperature α2 amylase and heat-resistant glucoamylase in order to simplify the process and save water and energy. If α2 amylase can liquefy at pH4. 5 and glucoamylase can be carried out at a temperature above 60℃. Imagine how much benefit these will bring? It not only liquefies at pH4. 5, but it can also avoid the formation of maltulose. Acid-resistant α2 amylase and heat-resistant glucoamylase have been studied abroad for many years, and there are also many reports. For example, an acid-resistant α2 amylase (KOD- 1) was reported in Japan, which reacted at pH4. 5, 65438 005℃ in 30% starch slurry. The residual enzyme activity was 75%. This enzyme liquefies at pH 4. 5 and 60℃ for 60 minutes to obtain liquefied solution DE 14. After saccharification with glucoamylase, 0. 1%for 48 hours, and the glucose content reached 95. The activity of α2 amylase of Bacillus subtilis was the same as that of control at pH5. 8 (Glucose content) The acid resistance of Bacillus licheniformis α _ 2 amylase was improved by replacing the 7-position methionine with other amino acids through protein engineering. Once this enzyme is industrialized successfully, it will greatly change the face of saccharification-related industries.
3 Conclusion
With the decrease of energy and the increase of population in the world, water resources and food are becoming more and more scarce. Due to the enhancement of human environmental awareness, it is more urgent for industry to transform traditional processes with enzymes. Therefore, it is urgent to improve the yield of enzyme, reduce the production cost and develop new varieties and new uses of enzyme. The development of genetic engineering and protein engineering has created favorable conditions for the development of enzyme preparation industry. Enzymes with special effects on substrates, enzymes produced by animals and plants will be produced by microbial fermentation, or enzymes produced by unusable microorganisms will be produced by safe strains.