基于通气量调控的灵芝菌丝体胞内多糖发酵工艺优化

A Aeration Volume Strategy for Enhanced Intracellular Polysaccharide Production by Ganoderma lucidum Mycelium Based on Submerged Culture

采用5L搅拌式发酵罐进行灵芝(Ganoderma lucidum)液态深层发酵实验,考察通气量对灵芝菌丝体生长和胞内多糖合成的影响。结果表明:在保持其它因素不变的条件下,通气量9 L/min时菌丝体干重最高,达到15.42 g/L;通气量6 L/min时胞内多糖得率最高,为2.10 g/L。根据发酵过程中菌丝体生长的比生长速率、胞内多糖比合成速率,提出四阶段通气量控制策略:0～31.2 h通气量为6 L/min;31.2～43 h通气量为9 L/min;43～55 h通气量为6 L/min;55～96 h通气量为5 L/min。利用上述策略发酵得到的菌丝体干重为17.35 g/L,比9 L/min条件下提高了12.59%,胞内多糖得率为2.83 g/L,比6 L/min条件下提高了35.75%。研究结果可为规模化液态深层发酵生产灵芝胞内多糖提供参考。

The submerged culture of Ganoderma lucidum was carried out in a 5 L stirred fermentor to evaluate the effects of aeration volume on the growth of mycelium and the synthesis of intracellular polysaccharide were investigated. The results showed that the maximum mycelial dry weight was 15. 42 g/L when the aeration volume was 9 L/min, and the maximum intracellular polysaccharide yield was 2.10 g/L when the aeration volume was 6 L/min. According to the mycelium specific growth rate and the intracellular polysaccharide specific synthesis rate during fermentation, a four-stage ventilation control strategy was proposed: aeration volume was 6 L/min from 0~31.2 h,aeration volume was 9 L/min from 31.2~43 h,aeration volume was 6 L/min from 43 ~55 h,aeration volume was 5 L/min from 55 ~96 h. By the above strategy the mycelium dry weight reached 17. 35 g/L, which was 12. 59% higher than that under the condition of 9 L/min. The intracellular polysaccharide yield reached 2.83 g/L, which was 35.75% higher than that at 6 L/min. The application of the four-stage aeration volume regulation during the submerged culture of G. lucidum polysaccharide proposed in this study can provide a reference for the large-scale fermentation of G. lucidum polysaccharide.