仔猪源罗伊氏乳酸杆菌生物学特性的研究

 研究了罗伊氏乳酸杆菌的生物学特性包括生长曲线、耐热存活率、耐酸存活率、贮藏存活率以及发酵参数。采用均匀设计的试验设计对影响乳酸杆菌发酵较大的6个因素如碳源、氮源和时间进行优化。试验结果表明,罗伊氏乳酸杆菌的浓度在开始时有所下降,经过2 h之后从1.0×10³数量级迅速上升,到第22 h接近1.0×10¹⁰数量级,到40 h细菌的数量级开始缓慢下降。75 ℃处理15 min之后存活率为31.3%,经过1个月贮藏存活率为85.5%,pH 2.0处理6 h的存活率为72%. 优化的发酵参数为:时间20 h;葡萄糖10 g/L;蔗糖60 g/L;胰蛋白胨30 g/L;酵母浸粉5 g/L;柠檬酸铵12 g/L. 试验表明了罗伊氏乳酸杆菌具有良好的抗逆性,生长繁殖迅速,可以用作益生菌生产菌种。

Study of Biological Characteristics of Lactobacillus reuteri Originated from Piglet

The biological characteristics of the L.reuteri originated from weaning piglet were investigated and fermentation parameters was optimized by means of uniform design. Lactobacillus growth curve, survivability after 75 ℃ treatment for 15 min, pH 2.0 treatment for 6 h and storage for 1 month, respectively, were measured. The concentration of L. reuteri decreased slightly in the first hour and increased very quickly from 1.0×10³ CFU/mL to about 1.0×10¹⁰ CFU/mL in 22 h, but fell down in 40 h. L.reuteri survivability after 75 ℃, storage, and pH 2.0 treatment was 31.3%,85.5%,72%, respectively and optimized fermentation parameters were as follows: culture time 20 h, glucose 10 g/L, sucrose 60 g/L, peptone 30 g/L, yeast extract 5 g/L, and ammonium citrate 12 g/L. The lactobacillus showed excellent growth characteristics and good resistance to stress so it can be used in piglet feed as a probiotics bacterium.