[Preparation of immobilized Lactobacillus plantarum agent for silage]

Lactic acid bacteria and cellulose degrading bacteria play an important role in fermentation process of silage, because they can prevent the rancidity and increase the nutritive value of silage. But the propagation of lactic acid bacteria will inhibit the activity of cellulose degrading bacteria in the silage fermentation system. This problem can be solved by releasing lactic acid bacteria and cellulose degrading bacteria in different time. Therefore, we immobilized lactic acid bacteria as a microbial agent for sustained release. Firstly, the optimal balling concentration of the composite immobilized carrier and composite immobilized carrier were obtained by immobilization of blank balls and corncob adsorbed Lactobacillus plantarum S1 respectively. The best immobilization condition of L. plantarum S1 was obtained by comparing the immobilized rate and balling effect of two kinds of balls, which were embedded by sodium alginate (SA), CMC-Na and embedded-crosslinked by SA, CMC-Na, polyvinyl alcohol (PVA). The results showed that the best balling concentration was achieved by using 6% PVA+0.4% SA+0.3% CMC-Na for embedding-crosslinking and 1.2% SA+0.5% CMC-Na for direct embedding respectively. In addition, comparing with the mechanical strength and embedding rate of five kinds of immobilization process, the best immobilized process was obtained by adding of the mixture of immobilized carriers (1.2%SA+ 0.5%CMC-Na) and corncob adsorbed L. plantarum S1 slowly into 4% CaCl₂ for 24 hours. The corncob adsorption and SA embedding methodology can effectively increase the embedding efficiency of Lactobacillus plantarum S1.