| abstract |
The present invention relates to polynucleotide molecules comprising nucleotide sequences encoding an aveC gene product, which polynucleotide molecules can be used to alter the ratio or amount of class 2:1 avermectins produced in fermentation cultures of <i>S. avermitilis</i>. The present invention further relates to vectors, host cells, and mutant strains of <i>S. avermitilis</i> in which the aveC gene has been inactivated, or mutated so as to change the ratio or amount of class 2:1 avermectins produced. |