韦伯灵芝漆酶生产中试研究

Study on pilot-scale fermentation of Ganoderma weberianum for laccase production

以韦伯灵芝（Ganoderma weberianum）TZC-1为生产菌株,在前期优化的摇瓶培养条件和5 L发酵罐小试生产工艺条件的基础上,对该菌株在50 L发酵罐进行中试放大,确定韦伯灵芝漆酶在50 L发酵罐的中试发酵工艺参数。结果表明：以3 d种龄种子按8%的接种量转接至发酵罐进行中试发酵,发酵温度28℃,装液量30L,采用分阶段控制p H和溶解氧浓度（DO）的策略,发酵初期（0~48 h）p H控制在6.0,48 h后p H控制在4.5~5.0范围内;0~36 h内控制搅拌转速100 r/min,通气量10 L/min;36~72 h内控制搅拌转速150 r/min,通气量15 L/min;72~96 h内控制搅拌转速200 r/min,通气量20 L/min;96 h至发酵结束搅拌转速250 r/min,通气量15L/min。发酵前72 h DO保持在15%~30%有利于菌丝生长,72 h后DO保持在10~15%有利于漆酶的积累。发酵144 h选择放罐,可获得18.8 L发酵原液,其漆酶活力可达27 667.7 U/L,是摇瓶发酵水平的2.5倍。

Based on our previous shaking-flask and 5-L fermentor experiments,pilot-scale fermentation for laccase production was investigated in a 50-L fermentor with G. weberianum TZC-1 as producing strain. The optimal pilotscale fermentation conditions and parameters were determined. The results showed that the optimal conditions were as follows： seeds age was 3 d,inoculum size was 8%,fermentation temperature was 28 ℃,and the volume of liquid medium was 30 L. p H and dissolved oxygen（ DO） were periodically controlled in the process of fermentation. p H value was 6. 0 within the first 48 h and 4. 5 ~ 5. 0 after 48 h. The agitation speed and aeration rate are 100 r / min and10 L / min within the first 36 h,150 r / min and 15 L / min during 36 ~ 72 h,200 r / min and 20 L / min during 72 ~ 96 h,and 250 r / min and 15 L / min after 96 h,respectively. 15 ~ 30% DO was favorable for mycelia growth within the first 72 h,and 10 ~ 15% DO was favorable for accumulation of laccase after 72 h. Fermentation was finished after 144 hours and 18. 8 L of enzyme liquid was obtained. The total enzyme activity was 27 667. 7 U / L. This activity was 2. 5times of that from our previous shaking-flask fermentation. The results of this study would be very useful for the laccase production by large tank fermentation.