[关键词]
[摘要]
本文研究了培养条件中不同种类、不同浓度的氮源和表面活性剂、发酵时间、温度、转速对黑曲霉全细胞生物量及水解活性的影响规律。研究发现,氮源对于黑曲霉细胞中具有水解活性的诱导酶系的产生具有一定的促进作用,且作用结果因氮源种类不同而异,其中酵母膏对黑曲霉具有最佳的培养效果;当酵母膏质量浓度为1.5 g/L时,黑曲霉生物量达到1.35 g/L,且水解活性达到66.45%。表面活性剂中Triton X-100培养的黑曲霉全细胞催化剂的水解活性表现最佳,当其含量为0.5%时,黑曲霉水解催化效率达到最大值。无机盐种类、浓度及培养温度和转速等条件对黑曲霉细胞生长和水解活性的影响也进行了研究,并确定具有水解活力的黑曲霉细胞的最佳培养方法为:酵母膏1.5 g/L,Triton X-100 0.5%;MgSO4·7H2O 1 g/L;KH2PO4 1 g/L,KCl 0.5 g/L;(NH4)2SO4 1.5 g/L;KCl 0.5 g/L;无水CaCl2 0.1 g/L;温度35 ℃,转速140 r/min。在该条件下,黑曲霉细胞生长量和水解效率分别达到1.73 g/L和90.23%。
[Key word]
[Abstract]
The effects of different culture conditions, including different types and concentrations of nitrogen sources and surfactants, fermentation time, temperature, and rotation speed, on the biomass and hydrolytic activity of Aspergillus niger (A. niger) cells were studied in this paper. The results showed that different nitrogen sources enhanced the production of the induced enzymes with hydrolytic activities in A. niger cells, and the rate of enhancement by the different nitrogen sources were different. Among the tested nitrogen sources, yeast extract showed the best inducing effect on the cells. For yeast extract concentration of 1.5 g/L, the biomass of A. niger corresponds 1.35 g/L. Among the surfactants examined, the optimal hydrolytic activity was found in the A. niger cells cultured using Triton X-100. In the culture media with 0.5% Triton X-100, the hydrolysis efficiency of A. niger reached 58.12%. In addition, the effects of inorganic salts, culture temperature, and rotation speed were also investigated and the optimal conditions to cultivate Aspergillus niger cells with hydrolytic activities were as follows: yeast extract 1.5 g/L, Triton X-100 0.5%, magnesium sulfate heptahydrate 1 g/L, monopotassium phosphate 1 g/L, potassium chloride 0.5 g/L, ammonium sulfate 1.5 g/L, and anhydrous calcium chloride 0.1 g/L. The ideal culture temperature and rotation speed were confirmed as 35℃ and 140 r/min, respectively. Under the optimal culture conditions, biomass and hydrolysis efficiency of A. niger cells were 1.73 g/L and 90.23%, respectively.
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[基金项目]
国家自然科学基金资助项目(31270636、21676105);新世纪优秀人才计划(NCET-12-0192);中央高校基本业务费(2015ZZ111)