固定化细胞生产乳酸的研究

Study on production of lactic acid by immobilized cells

以海藻酸钠为材料固定鼠李糖乳杆菌ATCC10863.6#,研究不同条件对L-乳酸的影响。结果表明,利用2%海藻酸钠得到的固定化细胞颗粒稳定性好,可维持150h无破裂,同时L-乳酸产量也相对较高。发酵培养基中酵母粉的最适浓度为3.0g/L,最适发酵温度为42℃,加入的最适接种细胞量为15%,最佳凝胶珠直径为2.5mm～3.0mm。通过4批次的重复发酵培养,第1批次发酵时间为48h,L-乳酸产量为40.1g/L。后3批次发酵时间均缩短为36h,L-乳酸产量约为45g/L。

The cells of Lactobacillus rhamnosus ATCC 10863.6 were immobilized by sodium alginate. Then the effect of various conditions on pro duction of L-lactic acid was investigated. The results showed that 2% sodium alginate was the optimal concentration for immobilization which could keep the cell stabilized for 150 h with high L-lactic acid yield. The optimal fermentation conditions were： 3.0 g/L yeast extract, 15% inoculation volume, fermentation at 42℃ and the diameter of gel granules within 2.5-3.5 mm. The results of 4-batch repeated fermentation showed that： the fermentation time of the first batch was 48 h with 40.1 g/L L-lactic acid production, while in the other 3 batches fermentation time condensed as 36 h. with 45 g/L L-lactic acid production.