温度对β-甘露聚糖酶在毕赤酵母中表达的影响

摘要

β-甘露聚糖酶已经广泛的在毕赤酵母中异源表达，为了提高β-甘露聚糖酶在毕赤酵母中的产量，本文研究了培养温度对β-甘露聚糖酶在毕赤酵母中表达的影响。通过比较不同温度下β-甘露聚糖酶在转录和蛋白表达水平的差异，发现降低温度虽然降低了mRNA表达量，但是外源蛋白得到积累增加；降低培养温度可以显著提高重组菌株的活性，从而减少细胞死亡带来的胞内蛋白酶的释放，最终使得低温下发酵液中的蛋白酶活力显著下降。研究结果表明降低培养温度能显著提高β-甘露聚糖酶在毕赤酵母中的表达量。%β-Mannanase has been extensively expressed heterologously in Pichia pastoris. The effect of the culture temperature on the expression ofβ-mannanase in Pichia pastoris was investigated in order to improve the production ofβ-mannanase in Pichia pastoris. Through comparing the difference of transcription and protein expression levels ofβ-mannanase under different culture temperature, it’s found that mRNA level decreased with decreasing of the temperature, but exogenous protein was accumulated. Lowering culture temperature could evidently improve the cell aviability of the recombinant strain, which could reduce the release of intracellular protease from the death cell, ultimately make the protease activity in the fermentation broth decrease significantly under the low temperature cultivate condition. The research results show that lowering culture temperature can evidently improve the expression ofβ-mannanase in Pichia pastoris.