氨基酸对于Monascus ruber生物合成Monacolin K影响的研究

在Monacolin K发酵中添加氨基酸后发现较高质量浓度的氨基酸高度抑制了Monacolin K的产量。0.1 g.L-1的D-甲硫氨酸在发酵第4 d添加可以提高产量30%以上,而L-甲硫氨酸则没有此功能,D,L-甲硫氨酸因D-甲硫氨酸的关系也有一定的增产效果。以甲硫氨酸代替蛋白胨作为主要氮源,则抑制了polyketide途径的前期步骤,因此严重抑制了色素及Monacolin K的生产。另外,发现1 g.L-1的L-苯丙氨酸的添加时间越早越有利于Monacolin K的生产,在起始时添加发酵单位可达135.9 mg.L-1,可能是因为L-苯丙氨酸经过脱氨后,可以进入polyketide途径从而促进了Monacolin K的生产。

Study on Effects of Amino Acid Supplement on Monacolin K Production by Monascus ruber

The effects of amino acid supplement on monacolin K production by Monascus ruber were investigated.Amino acids of higher concentration such as 10 g·L~(-1) or 1 g·L~(-1) conld inhibit monacolin K production.D-form and D,L-form of methionine could improve the yield of monacolin K when they were added at the forth day of the fermentation.And D-methionine could increse monacolin K production by 30%.The production of pigment and monacolin K was almost stopped when methionine was used as the main nitrogen source of the medium.Addition of 1 g·L~(-1) L-phenyalaine enhanced monacolin K production to 135.9 mg·L~(-1)(control 101.3 mg·L~(-1)when the addition time was early.