ARS | Publication request: ANTIBACTERIAL TOXINS ARE OVERPRODUCED IN A GENE DISRUPTION MUTANT OF METARHIZIUM ANISOPLIAE

Submitted to: Society for Invertebrate Pathology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 30, 2005
Publication Date: August 7, 2005
Citation: Krasnoff, S., Moon, Y., Donzelli, B.G., Churchill, A.C., Vandenberg, J.D., Gibson, D.M. 2005. Antibacterial toxins are overproduced in a gene disruption mutant of metarhizium anisopliae. Society for Invertebrate Pathology Annual Meeting. p. 50.

Technical Abstract: A Metarhizium anisopliae mutant (B1-3) in which a nonribosomal peptide synthetase (NRPS) gene was disrupted produces destruxins and exhibits a marked increase in the production of a complex mixture of secondary metabolites not previously described from this fungus. Overproduction of these compounds in B1-3 imparts a yellow pigmentation to the culture medium of the fungus. This change in phenotype is correlated with a second, uncharacterized mutation distinct from the NRPS gene disruption. Using ESI-MS, as well as 1- and 2-D NMR spectral analyses, we identified two major components in the pigment mixture, NG-391 and NG-393, which were previously reported from Fusarium species as stimulants of nerve-cell growth. These compounds are closely related to another family of Fusarium metabolites, the fusarins, mutagenic mycotoxins that contaminate corn. They consist of a 3-alkenoyl-3, 4-epoxy-2-pyrrolidinone moiety attached to a substituted pentaene unit that isomerizes readily, especially upon exposure to light. In preliminary assays, NG-391 exhibited antibacterial activity.