Engineering strain for producing cordycepin and cordycepin derivative 3 '-deoxyinosine as well as preparation method and application of engineering strain

The invention belongs to the field of genetic engineering and process engineering, and discloses an engineering strain for producing cordycepin and a cordycepin derivative 3 '-deoxyinosine as well as a preparation method and application of the engineering strain. Comprising codon optimized genes Cm1 and Cm2, a gene amplification and recovery fragment, a methanol induced promoter fragment and a terminator fragment, an expression vector is connected to the genes and then transferred into pichia pastoris for screening, and the pichia pastoris engineering strain protected by the invention is obtained and can be applied to production of cordycepin and derivatives thereof. The engineering strain prepared by the preparation method has huge advantages in production of cordycepin and derivatives thereof, the production efficiency of cordycepin is greatly improved due to the fact that the specific Cm1 and Cm2 genes are produced by utilizing the specific cordyceps militaris strain, and a green process for producing cord