Development and application of xylanase-containing probiotics

The xylanase-containing probiotic feed additive is a xylanase prepared from white rot fungi and is combined with a safe and pollution-free feed additive prepared by fermenting a beneficial strain such as Bacillus, lactic acid bacteria, yeast, and feed grade carrier. . The wood polyzyme produced by the white rot fungus can convert the non-starch polysaccharides which are not absorbed and utilized by the animal into nutrients, such as xylan, α-glucose, β-galactose, pectin and cellulose contained in the feed diet. Moreover, it also has the effect of eliminating the NSPS multi-nutrient absorption factor. After the microbial preparation enters the digestive tract and digestive system of the animal, the beneficial microorganisms rapidly multiply in the digestive tract, forming a competitive inhibition effect on the pathogenic bacteria. Bacillus and Candida utilis can destroy the plant cell wall in the feed during the metabolism of livestock and poultry, and degrade cellulose and pectin into monosaccharides and oligosaccharides, which can be metabolized in the intestinal tract of livestock and poultry to produce various digestive enzymes. , amino acids, cellulose, etc., can be used as nutrients by livestock and poultry, thereby promoting the digestibility of nutrients in the feed and promoting the growth of livestock and poultry; lactic acid bacteria can inhibit the growth of a variety of Gram-negative pathogens, can improve The production of immunoglobulin A in livestock and poultry produces anti-infective ability in the intestine, so it can improve the disease-free ability of livestock and poultry, enhance disease resistance and reduce the occurrence of diseases, thereby indirectly promoting animal growth and improving feed conversion and utilization. The role.

1. Materials and methods

1.1 strain

White rot fungus, Bacillus subtilis, Candida utilis, Bacillus licheniformis, lactic acid bacteria.

1.2 medium and raw materials

Corn flour, rice bran, bran, brown sugar, corn cob, peptone, glucose, soybean meal, potassium dihydrogen phosphate, beet pulp.

1.3 process flow chart

1.4 Operation points

1.4.1 Preparation of xylanase powder

The white rot fungus strain was inoculated in a liquid medium, activated at 25 ° C, and shaken for 5 days to obtain a white rot fungus culture solution; after dissolving the peptone with water, the bran and corn cob were mixed and stirred at 120 ° C. The bacteria were incubated for 30 min, cooled to 30 ° C, and then added to the white rot fungus culture medium for further expansion culture. The temperature was controlled at 30-35 ° C, fermentation was 8.5 d, and the xylanase solution was obtained. The xylanase solution was obtained at 60 ° C. Concentration is carried out, and when the concentration is more than 50%, spray drying is carried out to obtain a xylanase powder.

1.4.2 Activation and expansion of compound probiotic strains

1.4.2.1 Preparation of compound probiotic culture solution

After dissolving glucose, sucrose and potassium dihydrogen phosphate with water, adding soybean meal and beet pulp, mixing and stirring, sterilizing at 120 ° C for 30 min, cooling to 30 ° C, and respectively connecting Bacillus subtilis, Lactobacillus acidophilus and calving Saccharomyces cerevisiae was cultured in pure culture. Bacillus subtilis was cultured at 45-50 °C for 48 h, Lactobacillus acidophilus was cultured at 35-37 °C for 72 h, and Candida utilis was cultured at 25-30 °C for 48 h. After the culture was completed, it was carried out in equal volume. Mix and prepare a compound probiotic culture solution.

1.4.2.2 Preparation of compound probiotic fermentation broth

After dissolving brown sugar and potassium dihydrogen phosphate with water, adding soybean meal and beet pulp, mixing and stirring, sterilizing at 95 ° C ~ 100 ° C for 1 h, cooling to 30 ° C, and connecting to the compound probiotic culture solution, the temperature is controlled at 30 ° C ~ The mixture is cultured at 34 ° C for 72-80 h to obtain a probiotic fermentation broth.

1.4.2.3 Preparation of compound probiotic powder

Mix the corn flour and soybean meal powder evenly, dissolve the brown sugar with water, sterilize at 100 ° C for 1 h, wait until the temperature drops to 30 ° C, then add the mixed probiotic fermentation broth and mix it evenly on the mixture of corn flour and soybean meal. Stir well, keep the mixture of corn flour and soybean meal at 28-30%, control the temperature at 30-35 °C for 5 days, then control the temperature at 25-30 °C, anaerobic fermentation for 2 days at 50 °C. Dry at a temperature and pulverize to obtain a composite probiotic powder.

1.4.3 mixing ratio

The mixing ratio of the xylanase powder to the compound probiotic feed additive is from 1 to 10:99 to 90.

2. Results and discussion

2.1 Sensory testing

Before the fermentation of the probiotic bacteria powder, the materials are held in groups, and there is no obvious water sample. The color is the original color of the raw materials and has no other odor. In the middle of fermentation, Bacillus subtilis has a special astringent taste, the hand holding material has a slippery feel, and the hyphae can be seen by the naked eye. The color of the lactic acid bacteria turns yellow, slightly aroma of the wine and sweet and sour, the yeast is darker in color and has a yeasty aroma. . In the late stage of fermentation, the hands are clumped, loose, and the color is dark yellow, with a strong wine flavor and sweet and sour taste.

2.2 Test indicators (see Table 1)

2.3 Determination of live bacteria

After the preparation of the xylanase-containing probiotic feed additive, the number of viable cells was determined by plate culture counting method. The number of viable cells in the beef extract medium was 2×109/g or more, and the number of viable cells in the anaerobic chamber was 0.5×108/g or more in the lactic acid bacteria culture in the lactic acid bacteria, and the yeast was cultured in Martin. The number of viable cells measured by the base was 0.5×10 8 /g or more.

2.4 pH determination

The pH is 6.8, which is close to neutral and suitable for livestock and poultry.

2.5 enzyme activity assay

The results of enzyme activity measurement of the product were as follows: the amylase activity was determined by the iodine-starch colorimetric method to be 200 μg/g, the cellulase activity was determined by spectrophotometry to be 350 μg/g, and the protease activity by the Folin method was 420 μg/g. Studies have shown that enzyme preparations in feed can promote the digestibility and digestion rate of nutrients in livestock and poultry.

3. Feeding test

3.1 Add xylanase-containing probiotic feed additive to the chicken feed by 0.1-0.3% of the total weight of the feed, select 420 1 day old broilers, and select 400 healthy broilers, randomly divided into two groups, each group of 200 Only in the same house, the experimental design followed the same price diet, the control group was fed ordinary feed (including antibiotics), and the test group was fed with xylanase-containing probiotic feed additive and ordinary feed without antibiotics.