As the food safety awareness of people continuing to enhance, microecologics instead of antibiotics as feed additives have been widely recognized by feed industry, with its natural, safe, non-reside and other adventage. Because of the special characteristic of natural strong stress resistance, high temperature tolerance, acid and alkali tolerance, and easy storage, probiotics of bacillus became a research focus at home and abroad. This study developed subtilis-lichens-natto triple bacillus viable preparation through experiments, provide a theoretical basis and technical support for the industrial production of probiotics and the application in raising of weaned piglet.This study combined 3 strain of bacillus of subtilis(B.S),lichens(D.Y) and natto(N.T) to dual culture, obtained triple bacillus, its feed enzyme activities were:protease 126.72 U/mL, amylase 31.31 U/mL, cellulase 1.77 U/mL,β-mannase 2.42 U/mL. Identify of colonial morphology,cell characteristics,physiological and biochemical characteristics of 3 strains were conducted. Through orthogonal and single factor experiment, obtained optimum medium composition ratio:1%(v/v) waste molasses,0.5%(w/v) soybean powder,0.3%(w/v) calcium chloride. The favorite fermentation conditions:initiative pH7.5, inoculation amount5%(v/v), liquid volume 10~30%(v/v), culture temperature34℃, and ferment time 20 h. Utilizing industrial residues molasses,soybean powder as carbon,nitrogen, fundamentally reduced the cost of production. Based on the optimized medium with 5%(w/v) wheat bran and in standing fermentation liquor after the end of culture for 48 h, the sporulation rate of triple bacillus was increased to 96.2% or more. Through test, the triple bacillus preparation of high-temperature and simulated pig gastrointestinal solution was well tolerated, under a protective agent[5%(w/v) glucose],-7℃(frozen) condition, after 90 d the number of viable count remained at 109 cfu/g level, the survival rate up to 21.49%. Triple bacillus by 5 t level of pilot scale fermentation production, the viable count of bacterial sludge after centrifugation as high as 9.0×1012 cfu/g, the viable cells of preparation were 4.5×1010 cfu/g. The results of feeding trial of piglets showed that triple bacillus probiotics can make piglets daily weight raised by 20.72% (P>0.05), feed-weight ratio reduced by 12.36%(P<0.05), piglets diarrhea rate reduced by 22.73%(P>0.05), feed efficiency increased, economic efficiency enhanced significantly.From the above, the subtilis-lichens-natto triple bacillus viable preparation prepared by this study have low cost,favorable stability and high economic efficiency, as feed additive in piglet production will appear very broad application prospects.
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