基于混菌耦合发酵策略合成3′-唾液酸乳糖

Synthesis of 3′-sialyllactose by coupling fermentation with different strains

唾液酸乳糖在婴幼儿配方奶粉产业展现出潜在、广阔的市场前景,但是目前缺少有效、廉价的合成方法。针对该问题,首先构建了2株工程菌JM109(DE3)/pET28a-neuA和JM109(DE3)/pET28a-nst,分别用于合成胞苷单磷酸-N-乙酰神经氨酸(cytidine 5′-monophosphate N-acetylneuraminic acid,CMP-Neu5Ac)和3′-唾液酸乳糖;然后优化了JM109(DE3)/pET28a-neuA合成CMP-Neu5Ac体系;最后通过将啤酒酵母、JM109(DE3)/pET28a-neuA和JM109(DE3)/pET28a-nst耦合发酵,实现了3′-唾液酸乳糖的3菌株全细胞耦合催化合成。由于采用混菌耦合发酵策略来进行3′-唾液酸乳糖的生产,其生产模式不再像酶法一样繁琐和价格高昂,并且实现了CMP-Neu5Ac的高效再生和供给,为经济且规模化生产3′-唾液酸乳糖奠定了技术基础。

Sialyllactose has broad market prospects in infant formula industry.However,it is still a challenge to produce sialyllactose in large-scale.Escherichia coli JM109(DE3)/pET28a-neuA and E.coli JM109(DE3)/pET28a-nst were constructed to synthesize cytidine 5′-monophosphate N-acetylneuraminic acid(CMP-Neu5Ac)and 3′-sialyllactose,respectively.And then the optimized condition of CMP-Neu5Ac synthesis by E.coli JM109(DE3)/pET28a-neuA was developed.Finally,the whole-cell coupling fermentation method with beer yeast,E.coli JM109(DE3)/pET28a-neuA and E.coli JM109(DE3)/pET28a-nst was established to achieve 3′-sialyllactose.The CMP-Neu5Ac can be supplied and efficiently regenerated by the method,which will lay a forceful technical foundation for the economical and large-scale production of 3′-sialyllactose.