Tylosin producing bacterium, genetic modification method and application thereof

The invention relates to a tylosin producing bacterium, a genetic modification method and an application thereof. Through in-frame deletion of a mycaminose synthetic gene cluster (comprising ty1CVII, ty1CV, ty1CIII, ty1CIV and ty1CII) in a tylosin biosynthetic gene cluster, a synthetic precursor, namely a strain of tylosin B (Tb) which can be used to produce tilmicosin directly, is obtained. The tylosin producing bacterium provided by the invention can be directly fermented to produce the synthetic precursor of tilmicosin, so that the synthetic process of tilmicosin is simplified.