| 摘要: |
| 【目的】研究不同复合氮源对土曲霉生物合成洛伐他汀的影响。【方法】以酵母粉、蛋白胨、花生粉、燕麦粉、玉米浆和黄豆粉分别为复合氮源，通过摇瓶培养检测培养过程中洛伐他汀产量及其关键中间代谢物2 甲基丁酸盐和monacolin J的积累量。【结果】以蛋白胨为氮源时，土曲霉细胞比生长速率最大，为8.06 d-1；以花生粉为氮源时，洛伐他汀比产物合成速率最大，为1.44 mg/(g·h)，同时培养过程中2-甲基丁酸盐和monacolin J对细胞得率明显高于其他氮源，均约为玉米浆的4倍；以酵母粉为氮源时，2-甲基丁酸盐的合成速率是monacolin J的4倍，其monacolin J转化率最高（92.0%），约是玉米浆的1.6倍。【结论】 不同复合氮源不仅影响次级代谢的碳代谢流，还可能通过调控洛伐他汀合成途径中的关键酶（LovD或LovF）影响其生产。 |
| 关键词: 土曲霉 生物合成 复合氮源 洛伐他汀 代谢调控 |
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| 基金项目:陕西省教育厅重点科研项目（99JK08） |
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| Effect of complex nitrogen source on lovastatin biosynthesis from Aspergillus terreus |
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| Abstract: |
| 【Objective】 Effects of various complex nitrogen sources on lovastatin biosynthesis from Aspergillus terreus were investigated.【Method】The production of lovastatin and the accumulation of its key intermediate metabolites such as 2-methylbutyrate and monacolin J were determined in the cultures by shake flask cultivation when yeast extract powder,peptone,peanut meal,oat meal,corn steep liquor,and soybean meal were regarded as the complex nitrogen source,respectively.【Result】The highest specific growth rate of 8.06 d-1 was produced when peptone was the sole nitrogen source.The highest specific lovastatin production rate of 1.44 mg/(g·h) resulted from the culture in which peanut meal was the sole nitrogen source.Simultaneously,the yields of 2-methylbutyrate and monacolin J on biomass resulted from peanut meal were all approximate 4 fold to that obtained from corn steep liquor and were much higher than those obtained from other four investigated nitrogen sources.The formation rate of 2-methylbutyrate was 4 fold to that of monacolin J in the presence of yeast extract while the percent conversion of monacolin J (92.0%) was approximate 1.6 fold to that obtained from corn steep liquor.【Conclusion】Different complex nitrogen sources probably affect both the carbon flux to secondary metabolism of A.terreus and the lovastatin production by regulating its key enzymes (LovD or LovF) involved in the biosynthetic pathway. |
| Key words: Aspergillus terreus biosynthesis complex nitrogen source lovastatin metabolic regulation |
