Study On Fermentation Characterstics Of Soybean Meal With Probiotic L. Casei Zhang And L. Plantarum IMAU10120

Probiotic can improve the quality of soybean meal and feed, which is a green feed additive with vast development foreground. In the present study, the fermentation characteristics of fermented soybean meal with probiotic L. casei Zhang and L.plantarum IMAU10120were evaluated and the preliminary application with the two probiotics in complete feed was also investigated. L. casei Zhang and L. plantarum IMAU10120were inoculated alone or mixed (1:1) with2×106cfu/g for soybean meal and complete feed fermentation, the changes of pH, dominated microbial groups, the crude protein content, SB A, AFB1, soybean oligosaccharides and organic acid levels in soybean meal were monitored during fermentation at25℃癈.Then blending the complete feed with the soybean meal as major protein material, the changes of pH and dominated microbial groups were monitored during fermentation at room temperature. The results are presented as follows:(1) L. casei Zhang and L. plantarum IMAU10120could grow rapidly in the soybean meal and the viable numbers of L. casei Zhang and L. plantarum IMAU10120rearched more than109CFU/g at the end of fermentation. During fermentation period, yeasts, mold, coliform bacteria, Bacillus and Clostridium were effectively inhibited by adding probiotics and the unexpected bacterium in trial groups were at significant lower level than control.(2) The dry weight content and crude protein content of soybean meal fermented by L. casei Zhang, L. plantarum IMAU10120and their mixture have no significant difference while the content of SBA decreased by27.24%,33.22%and59.14%, respectively. Moreover, the level of AFB1decreased to0.58,0.27and0.33μg/kg, which were far lower than the level of the national standard(≤10μg/kg) at the end of fermentation(3) L. casei Zhang and L. plantarum IMAU10120could degrade soybean oligosaccharides in soybean meal fermentation. The stachyose in three trial groups were significantly decreased by74.42%,71.32%and69.77%while the raffinose significantly decreased by21.70%,39.62%and40.57%. Sucrose, glucose and fructose were the major carbohydrates that to be utilized and sucrose was at extremely low level but not significant among groups at the end of fermentation.(4) Through L. casei Zhang and L. plantarum IMAU10120fermentation of soybean meal, the content of lactic acid and acetic acid of L. casei Zhang, L. plantarum IMAU10120and their mixture fermented soybean meal were significantly respectively increased to533.17,692.70,564.80and367.87,287.50,215.83mmol/L while butyric acid decreased. At the end of fermentation, butyric acid had not been detected. Propionic acid has not been detected throughout the whole experiment.(5) L. casei Zhang and L. plantarum IMAU10120were inoculated for complete feed fermentation which the pH decreased fastly and the pH lower than4.3in the end. During fermentation, the unexpected bacterium in trial groups were at significant lower level than control.These results indicate that soybean meal fermentation with L. casei Zhang and L. plantarum IMAU10120can significantly decreased the pH values and inhibited microbial pollution of complete feed. The nutritional value of soybean meal was improved and the content of AFB1was decreased with great application foreground.