Laccase is a polyphenol oxidase containing four copper ions. It belongs to copper blue oxidase and exists in the form of monomeric glycoprotein. Laccase exists in mushrooms, bacteria and plants, and can also survive in the air.
Laccase is a polyphenol oxidase (ρ-diphenol oxidase, EC1.10.3.2) containing four copper ions. It belongs to copper blue oxidase and exists in the form of monomeric glycoprotein. Laccase exists in mushrooms, bacteria and plants, and can also survive in the air. The only product after the reaction is water, so it is essentially an environmentally friendly enzyme. The unique catalytic properties of laccase make it widely used in biological detection. As an efficient biological detector, it has become an effective tool and method for the analysis of substrates, coenzymes, inhibitors and other components. As environmental awareness has been gradually valued in recent years, laccase has also become the research object of many scholars in recent years.
Laccase was first found in the secretions of sumac, and exists in the cell walls of many higher plants, such as the buds of tea. Laccases actually used in production are mainly derived from bacteria and fungi, and most fungi secrete laccases. The main production strain is white-rot fungi. At present, the application research of laccase mainly focuses on the decomposition of lignin, pulp bleaching, decolorization of dye wastewater, and degradation of toxic substances in the environment.
Application of Laccase
The bioremediation process is a process in which the contaminated environment is treated by biotransformation methods. Phenol and aromatic amines are the main substances that constitute environmental pollution, and laccase has a strong ability to degrade phenolic compounds. Fixing it on an organogel carrier can remove from the suspension the aromatic compounds that are contained in the water itself and mixed with the outside world. When the initial phenol concentration is 40 mgl, the laccase produced by Trametes villosa can remove 40% of the phenols in the water. The substrate of the action of laccase is insoluble in industrial wastewater through oxidation coupling, which is conducive to the complete removal of phenolic substances.
In recent years, researchers have confirmed that the polyphenols present in red wine have antioxidant effects. Treating red grape juice with the laccase produced by Trametes versicolor will reduce the phenolic substances with antioxidant properties in the grape juice. After the white grape juice is treated with the same laccase, the beneficial effect of the reduction of total phenolics on the quality will be higher than the beneficial effect of the potential antioxidant properties on the quality. Therefore, it is feasible to treat white grape juice with laccase. Another method is to choose a laccase isoenzyme to minimize the effect of laccase on the antioxidant phenolic substances in red wine. Those phenolic substances that do not exhibit antioxidant properties are rapidly degraded by laccase.
In the production process of edible fungus seed production, the addition of laccase preparation can accelerate the decomposition of lignin and other aromatic macromolecule compounds, and provide nourishment for mycelium. At the same time, it participates in the electron transfer of the respiratory process as an oxidase, providing more energy and promoting the synthesis, operation and accumulation of substances in the mycelium, thereby accelerating the growth of the mycelium and shortening the time for seed production. In the process of bagging material cultivation, the mycelium can also be kinked, forming more fruit body primordia, and increasing the yield of mushrooms. During the entire production process, laccase preparations can oxidize phenol into quinone, which acts as a toxin against bacteria and inhibits contamination by bacteria.
Beer will produce turbidity during long-term storage. The main reason is that a small amount of natural anthocyanin precursors (ie, polyphenol compounds) and proteins form a precipitate due to hydrogen bonding or hydrophobic interaction with proline residues. In the later stage of cold storage, the nucleophilic substitution of the benzene ring by the hydrophobic group of the protein can cause permanent turbidity. Polyphenols in production are generally removed by polyvinylpyrrolidone (PVCC) treatment. PVCC is not good for workers' health and has poor biodegradability, which has become a problem in wastewater treatment. Therefore, addingpolyphenol oxidase (such as laccase) is a better choice. Laccase is added in the final process of beer production to remove excess oxygen, thereby prolonging the shelf life of beer, and the polyphenol polymer aggregates caused by laccase can be removed by filtration.
The Naming and Characteristics of Restriction Endonucleases
Restriction enzymes, also known as restriction endonucleases, are enzymes that cut double-stranded DNA. Its cutting method is to cut the bond between the carbohydrate molecule and the phosphoric acid, and then create a nick on each of the two DNA strands without damaging the nucleotides and bases.
Introduction to Classification and Application of Cellulase
The optimum pH of cellulase is generally 4.5 to 6.5, which acts on cellulose and products derived from cellulose. Microbial cellulase is of great significance in converting insoluble cellulose into glucose and destroying cell walls in fruit and vegetable juice to improve the yield of juice.
Which Enzyme Preparations Are Often Used in Fruit and Vegetable Processing?
The so-called fruit and vegetable processing means to maximize the nutrient content of the fruit and vegetable through various processing methods, improve the edible value, and make the color, aroma and taste of the processed product more perfect.
