一株利用木糖产L-乳酸细菌的发酵特性研究

摘要

The growth of bacteria strain Lt takes oxygen,with the lag period of 6h and enters into the stationary growth phase at the 16th hour. Strain Lt can ferment xylose, glucose, D-mannose and L-arabinose into L-lactic acid with the conversion rate of 88.0%-98.7% , but failed with L-arabinose and lactose. The optimum fermentation me-mL medium in 250 mL bottle,inoculum size 10% ,shaker rev 160 r/min, at 46℃, inaerobically. Using pure xylose (60 g/L) as substrate, the L-lactic acid yield reached 57.35 g/L; using the corncob hydrolysate(reduced sugar 60 g/L) , the L-lactic acid yield reached 31.30 g/L.%对高效木糖乳酸菌Lt的发酵特性进行了研究,同时对其发酵玉米芯L-乳酸进行了初步探讨.Lt菌株生长需要氧气,延迟期约为6 h,16 h以后进入稳定期,可利用木糖、葡萄糖、D-甘露糖、L-阿拉伯糖产L-乳酸,转化率为88.0%-98.7%.最适发酵温度为46℃,从46-52℃产酸量均较高.用6%的纯木糖发酵48 h,L-乳酸产量为57.35 g/L,转化率约为95%;用含6%还原糖的玉米芯磷酸水解液发酵48 h,L-乳酸产量为31.30 g/L.该菌株具有发酵温度高、适温范围宽、发酵时间短、转化率高、L-乳酸纯度高等优点.