Yeasts are single-celled fungi that are round, oval, or cylindrical, and have a cell size of approximately 1 to 5 μm x 5 to 30 μm and a length of up to 100 μm. Yeast cells are rich in protein, amino acids and various vitamins, especially B vitamins and various digestive enzymes. In the feed industry, yeast is mainly used as a protein feed and was originally used as a protein supplement feed for ruminants. With the advancement of science, especially the rapid development of modern bioengineering technology, in addition to producing single-cell proteins as high-quality feed proteins, people also use different yeasts and different processing methods to develop various feed additives that have different effects on animals. . In general, Candida utilis, Candida tropicalis, Brewer's yeast, Candida lipolytica, Wine yeast, Pasteurella glutinosa, Fragrance yeast and Geotrichum candidum are suitable for feeds.
High-quality single-cell protein feed
With the development of animal husbandry production, livestock and poultry have become increasingly lacking in protein feeds. In 1980, the animal husbandry industry in the world required 430 million tons of protein, and by 1990 this figure had exceeded 524 million tons. By 2000, this figure had exceeded 900 million tons. Therefore, many countries have established new industries for single cell proteins. Feed yeast single cell protein refers to yeast single cell protein used as feed. Yeast protein has high nutritional value. The protein content of feed yeast dry matter can be as high as 50%. Its lysine content is higher than that of soybean, and it is close to animal protein. Its tryptophan content is more than 7 times higher than that of soybean, and it also contains B. The family vitamins, minerals and other physiologically active substances are multidimensional, high-protein active yeast feeds and have been widely used as single-cell proteins. Single cell proteins are produced, and single cell proteins are currently produced by Candida, Debaryomyces, Q. yoelii, and Rhodotorula. Using yeast to produce single cell protein (SCP), the production speed is fast and the cycle is short. Inoculation of yeast can reproduce for 1 to 3 hours.
Yeast not only can greatly increase the protein level of feed ingredients, yeast also contains rich enzymes, such as pepsin, amylase, etc., high digestibility, general digestibility can reach 80% to 90%. Yeast fermented feed can promote microbial reproduction, increase digestibility, promote weight gain and increase feed remuneration. When yeast fermented feeds are used to prepare diets, amino acid balance must be considered. In particular, the content of limiting amino acids such as lysine and methionine must meet the nutritional needs of animals. With the development of microbial engineering and fermentation engineering, yeast is increasingly used for the production of high-quality protein feeds.
Feed enzyme additives
Application of feed enzyme additives
Yeast cell wall lysis can produce a variety of enzymes, live yeast cells can also secrete a variety of enzymes, such as amylase, protease, cellulase and so on. Therefore, yeast can enhance the digestion and utilization of nutrients, promote the growth of livestock and poultry, increase their appetite, and enhance their ability to resist diseases and resist stress.
The production of RC feed yeast contains a high proportion of active yeast cells and digestive enzymes (amylase 17 mg/g, protease 168 GDU/g), which can promote animal digestion and absorption of feed and increase feed conversion. Experiments have shown that adding 1.48 % or 2.96 % of RC feed yeast to pig diets can promote pig growth and development and increase feed conversion. JW live bacteriocins containing yeast cultures, xylanases, β-glucanases, cellulases, acid proteases, etc., as the main components, are used in sub-pig unconventional feeds (15% sub-powder, 5% wheat bran substitute When 0.1% was added to 20% corn, the daily weight gain was 14.3% higher than that of the control group, 4.35% higher than that of the enzyme preparation group, and the feed utilization rate was 3.8% to 7.5% higher than that of the control group, which was 0.4% higher than that of the commercial enzyme group. %; 0.1% JW live bacteriocin was added to the conventional feed of the piglet. The daily weight gain of the test group was 8.5% higher than that of the control group, and the feed remuneration was increased by 6%. 0.1% JW live bacteriocin was added to the egg bird concentrate. The egg production rate in the test group was increased by 0.43% and the feed utilization rate was increased by 6.38% compared with the control group. The phytase produced by screened Candi鄄da Krusei WZ-001 was used to hydrolyze the phytic acid in soybean meal and bran to simulate the gastrointestinal pH environment of the animals against Candida krusei WZ- The ability of 001 phytase to dephosphorylate phytic acid in feeds that were degraded by two commercial enzymes identical to their enzyme activity was compared. The results showed that the amount of inorganic phosphorus released by WZ-00l phytase after hydrolysis of feed phytate for 10 hours was 4.89 times that of the original free phosphorus, and the hydrolysis rate of phytic acid was 67%, both higher than the two commercial enzymes with the same enzyme activity.
New Progress in Feed Enzyme Additives
Microorganisms can produce a variety of enzymes that can be used as feed additives. However, in general, natural strains produce low levels of enzymes, and their direct production costs are relatively high. Therefore, people began to construct genetically engineered bacteria to increase enzyme production and thus to produce large-scale production. Yeast can be used as a bioreactor for the production of various enzymes. Yeast is a host strain for the production of eukaryotic heterologous proteins, which is easy to genetically manipulate, combines the growth characteristics of prokaryotic organisms and post-translational modification of eukaryotic proteins. In recent years, with the completion of fermentation methods and the emergence of methanol-regulated promoters, Pichia pastoris has been widely used due to its unique advantages and potential. It can use methanol as a carbon source, which can grow fast and can reach a very high cell concentration. It is the ideal expression of foreign proteins. It is suitable for expressing intracellular or extracellular foreign proteins and has high stability. Adaptable, easy to handle, can be grown in inexpensive, non-selective media, and post-transcriptionally modified. Due to the many advantages of this expression system, more and more people are studying to use it as an expression system of a foreign gene to produce a feed enzyme of interest.
The Aspergillus niger glucoamylase GAI cDNA and the barley alpha-amylase gene were introduced into Saccharomyces cerevisiae GRF18 to obtain a yeast genetically engineered bacterium and the α-amylase and glucoamylase genes were highly expressed. The expression system of phytase A of Aspergillus niger N25 was highly expressed by using methanol yeast as the expression system. The expression level was nearly 70 times that of the original strain Aspergillus niger (35646.7 U/ml: 513.4 U/ml), and the optimal temperature for enzyme action was 55°C. The optimum pH value is 4.6, with higher enzyme activity in the pH range of 5.5 to 5.6, and the pH value is well tolerated. It was found that the phytase and natural phytase enzymes of A. niger963 expressed in recombinant methanol yeast have normal biological activity, and their expression levels are greatly increased. A large number of studies have shown that the use of yeast engineering bacteria to produce phytase is very promising. After the cloned and expressed the Aspergillus niger N402 acid xylanase gene, the gene was expressed in P. pastoris, and the xylanase produced by the laboratory-engineered genetically engineered bacteria was the most suitable. The effect pH is 4.0, basically stable between pH 2.0-5.5, the optimum temperature is 37°C, and the heat resistance is better. It is suitable for the physiological conditions of the digestive tract of animals. As a genetic engineering bacteria, yeast has a broad application prospect in the development and utilization of feed resources.
OTC Blue Type Welding Torch also has three types : the 200A type ,the 350A type ,the 500A type .The custom can choice the torch according to the rating,the duty cycle ,the wire size you use .
The OTC type welding torch has its own charactiscis as followes :
1. Interchangeable with the best know brand
2 .Ergonomics handle
3. Front and rear cable protection spring
4. Articulation to ease cable bending
5. Euro with mobiles pins
6 .Different adaptors available
OTC Type Welding Torch, OTC Type 350A Mig Torch, OTC Type Mig Torch, OTC Type 200A Mig Torches, OTC Type 500A Mig Torch
EDAWELD COMPANY LIMITED , https://www.jsedaweld.com