Method for regulating and controlling components of polymyxin B homolog

The invention discloses a method for regulating and controlling the components of a polymyxin B homolog. The method comprises the following steps: (1) constructing pMAD-DeltaA and pMAD-DeltaC; (2) transforming pMAD-DeltaA into CJX518 strains, conducting screening to obtain successfully-transformed strains, performing culturing and subculturing to obtain plasmid-lost strains, verifying the plasmid-lost strains as structural domain-replaced strains 518-A through PCR sequencing, transforming pMAD-DeltaC into the CJX518 strains, screening the pMAD-DeltaC transformed strains 518-A, carrying out culturing and subculturing to obtain plasmid-lost strains, and verifying the plasmid-lost strain as structural domain-replaced strains 518-AC through PCR sequencing; (3) carrying out seed culture to obtain secondary seeds; and (4) producing polymyxin B by inoculating the secondary seeds into a fermentation medium, and carrying out fermenting for 72 hours. According to the method disclosed by the invention, the components of