As a new type of high-efficiency feed additive, enzyme preparations can improve animal production performance and reduce excreta pollution. It also provides an effective way to open up new feed resources and reduce feed production costs. It also contributes to the efficient, environmentally friendly and environmentally friendly feed industry. Food conservation and sustainable development provide guarantees and possibilities. The research, development, promotion and use of feed enzyme preparations have become an important area of application of biotechnology in the feed industry.

Production method of feed enzyme preparation

The enzyme preparations currently added to feed are all produced by microbial fermentation. The conventional processes are: strain breeding, fermentation culture, and enzyme extraction. Various enzymes also exist in animals and plants, but the cost of extracting enzymes is extremely high, and production is limited by seasons. Using microorganisms to produce enzyme preparations has high yields, low production costs, and is not subject to seasonal restrictions. There are two methods for using microorganisms to produce feed enzyme preparations, one is solid fermentation and the other is liquid fermentation.

Compared with solid fermentation culture methods, liquid submerged fermentation has the following advantages: (1) The liquid suspension state is the most suitable growth environment for many microorganisms. (2) In a liquid environment, bacteria, substrates, and products (including heat) are easy to diffuse, allowing fermentation to proceed under homogeneous or quasi-homogeneous conditions, which is convenient for detection and control, and easy to expand production scale. (3) Liquid transportation is convenient and easy to mechanize operation. (4) The product is easy to extract and refine.

However, solid fermentation also has many advantages that liquid fermentation does not have, mainly as follows: (1) The culture medium is simple, mostly cheap natural substrates. (2) The low water content of the matrix can greatly reduce the volume of the biochemical reactor, without the need for wastewater treatment, less environmental pollution, and often does not require strict aseptic operation, and post-processing is convenient. (3) Ventilation is not necessarily continuous, but can generally be accomplished by intermittent ventilation or gas diffusion. (4) The yield of the product can be higher. (5) The equipment is simple, the investment is small, and the energy consumption is low.

Due to the low added value of the feed industry, feed enzymes do not need to be refined. Therefore, solid-state fermentation is more suitable. Domestic production of compound enzyme preparations generally uses solid-state fermentation, while liquid fermentation is mainly used for the production of phytase or the production of single enzyme preparations for compound enzyme preparations.

Types of enzyme preparations

Digestive enzymes: Animals can synthesize and secrete digestive enzymes into the digestive tract to digest nutrients. If you need to strengthen the role of endogenous enzymes in animals, you need to use exogenous animal digestive enzyme analogs. The structure and properties of the latter may be different from endogenous enzymes, but their functions are the same, mainly including amylase, protease and lipase.

Amylase mainly includes. Alpha-amylase, beta-amylase, glucoamylase and pullulanase function to catalyze the degradation of starch. Generally used in feed. α-Amylase is an endonuclease that catalyzes the random hydrolysis of 1 and 4 glycoside bonds within the starch molecule. And beta-amylase is an exonuclease. Amylase catalyzes the breakdown of starch into oligosaccharides, disaccharides, dextrins, or glucose and fructose. Animal digestive tracts and saliva contain amylase.

Protease Protease is the general name for a group of enzymes that catalyze the breakdown of peptide bonds. Proteases act on proteins and degrade them into small molecules of peptone, peptides and amino acids. Acidic and neutral proteases are often used in feeds. Proteases are also divided into endo- and exo-enzymes according to their mode of action. General microbial proteases are usually a mixture of endo- and exo-enzymes. Most of the proteases in animals are found in gastric juice and pancreatic juice, namely pepsin and trypsin, the former is an acid protease and the latter is an alkaline protease.

Lipase breaks down triglycerides (fats) into free fatty acids and glycerol. Gastric juice and pancreatic juice in animals contain a variety of lipases.

Non-digestive enzymes Non-digestive enzymes are usually enzymes that cannot be synthesized by animals themselves and are generally derived from microorganisms. It is mainly used to decompose substances that animals cannot digest or degrade anti-nutritional factors or toxic and harmful substances. It mainly includes cellulase, hemicellulase, phytase, pectinase, etc.

Cellulase breaks down cellulose into polysaccharides such as cellobiose and cellotriose. Beta-glucosidase breaks down cellobiose and cellotriose into glucose. It is generally believed that cellulase is a complex enzyme system. Cellulase can destroy the fiber-rich plant cell wall, allowing the starch, protein and minerals surrounded by it to be released and digested and utilized. At the same time, it can partially degrade the fiber into digestible reducing sugars, thereby increasing the dry matter of animal feed. , protein, crude fiber, starch and mineral digestibility. Feed processors and nutritionists are currently using a variety of cellulases in pig and poultry diets to improve the nutritional value of feeds.