Genetically engineered Streptomyces capable of thaxtomin production in the absence of thaxtomin-inducing conditions and methods of producing thaxtomin

A genetically engineered Streptomyces bacterium from a naturally non-pathogenic Streptomyces strain, the genetically engineered Streptomyces bacterium comprising:

• an exogenous, refactored thaxtomin biosynthetic gene cluster comprising one or more thaxtomin modules, each thaxtomin module comprising:
• one or more thaxtomin genes from a thaxtomin biosynthetic gene cluster from a plant pathogenic Streptomyces bacterium, the one or more thaxtomin genes selected from the group consisting of:
• a txtA gene encoding a TxtA protein, a txtB gene encoding a TxtB protein, a txtC gene encoding a TxtC protein, a txtD gene encoding a TxtD protein, a txtE gene encoding a TxtE protein, and a txtH gene encoding a TxtH protein, wherein the exogenous, refactored thaxtomin biosynthetic gene cluster as a whole comprises two or more thaxtomin genes, and
• one or more promoters operably linked to the one or more thaxtomin genes in the one or more thaxtomin modules,
• such that expression of the one or more thaxtomin genes in the exogenous, refactored thaxtomin biosynthetic gene cluster provides the genetically engineered Streptomyces bacterium with the ability to produce at least one thaxtomin compound in the absence of thaxtomin-inducing conditions, wherein the naturally non-pathogenic Streptomyces strain without the exogenous refactored thaxtomin cluster does not have the ability to produce the thaxtomin compound.