鼠李糖乳杆菌及枯草芽孢杆菌发酵对饲料品质的影响

该研究通过测定发酵饲料pH值、活菌数、乳酸含量及中性蛋白酶活性，筛选出适宜基础饲料发酵的鼠李糖乳杆菌（Lactobacillus rhamnosus）BLCC2-0038和枯草芽孢杆菌（Bacillus subtilis）BLCC1-0281，并对筛选出的鼠李糖乳杆菌和枯草芽孢杆菌进行单菌及混菌发酵方式进行了研究。结果表明，BLCC2-0038单独发酵72 h时pH值降至3.73，活菌数达到7.05×109 CFU/g，乳酸含量为48.67 mg/g；BLCC1-0281单独发酵72 h时，活菌数达到2.28×1010 CFU/g，中性蛋白酶活性达到3 207 U/g；BLCC2-0038和BLCC1-0281混菌发酵时，以鼠李糖乳杆菌/枯草芽孢杆菌配比为3∶1，2%接种量，有氧发酵方式最优，发酵72 h时鼠李糖乳杆菌活菌数为5.35×109 CFU/g，枯草芽孢杆菌活菌数为7.80×109 CFU/g，中性蛋白酶活性为1 407.83 U/g。

Effect of Lactobacillus rhamnosus and Bacillus subtilis fermentation on feed quality

By determination of fermented feed pH, viable count of bacteria, lactic acid content and neutral protease activity, the Lactobacillus rhamnosus BLCC2-0038 and Bacillus subtilis BLCC1-0281 that was suitable for basic feed fermentation were screened, and the fermentation conditions of single and double-strains were researched. Results indicated that at the condition of L. rhamnosus BLCC2-0038 single strain fermentation for 72 h, the feed pH reduced to 3.73, the viable count reached to 2.28×1010 CFU/g, and the neutral protease activity was 3 207 U/g. The optimum conditions for L. rhamnosus BLCC2-0038 and B. subtilis BLCC1-0281 double-strains fermentation (ratio 3∶1), aerobic fermentation, inoculum 2%, fermentation time 72 h. The viable count of L. rhamnosus and B. subtilis were 5.35×109 CFU/g and 7.80×109 CFU/g, respectively, and the neutral protease activity was 1 407.83 U/g.