碳源对土曲霉中洛伐他汀生物合成的影响

通过摇瓶培养考察碳源种类及其初始水平对土曲霉次级代谢物洛伐他汀生物合成的影响。蔗糖和葡萄糖等快速利用碳源产洛伐他汀量较低,且易积累其直接前体monacolin J;淀粉和甘油等缓慢利用碳源有利于细胞生长和产物合成,其monacolin J积累相对较少,甘油为碳源时,可获得最高产物量(937.5±12.3)mg/L,乳糖不利于细胞生长导致较低的产物量。以淀粉为碳源时,其初始水平的增加可促进洛伐他汀的合成,碳质量分数为2%时对底物利用率较高,4%时最高产物量可达(875.4±23.1)mg/L,monacolin J则在2%—3%时积累较多,同时产生较多的2-甲基丁酸。

Effect of carbon source on lovastatin biosynthesis in Aspergillus terreus

The effects of carbon source and its initial carbon level on lovastatin biosynthesis in Aspergillus terreus by shaking flask culture were investigated.The rapidly-utilized carbon source such as sucrose or glucose produced poor lovastatin and easily accumulated its direct precursor monacolin J.The slowly-utilized carbon source,like soluble starch or glycerol,was better assimilated for the cell growth and lovastatin biosynthesis and accumulated less monacolin J.Maximum lovastatin production of(937.5±12.3) mg/L was achieved in the presence of glycerol.Lactose inhibited cell growth,resulting in poorer lovastatin production.The increase of the initial carbon level promoted lovastatin biosynthesis when regarding soluble starch as the sole carbon source.The maximal lovastatin production of(875.4±23.1) mg/L was produced at the initial carbon mass fraction of 4% while its utilization on substrate was higher at 2%.The higher accumulation of monacolin J appeared at 2%-3% and more 2-methylbutyrate was formed.