Submitted to: Genetics of Microorganisms Symposium
Publication Type: Abstract Only
Publication Acceptance Date: October 20, 1996
Publication Date: N/A
Significant amounts of isoprenoid pathway carbon flow are utilized for the production of sesquiterpenoid toxins (trichothecenes) in the filamentous fungus Fusarium sporotrichioides. Trichothecene-deficient mutants of F. sporotrichioides have been generated by gene disruption (Tri5**-) in an effort to develop host strains for foreign isoprenoid pathway expression. To determine if isoprenoid precursors formerly channeled into trichothecene biosynthesis can be utilized to synthesize commercially valuable isoprenoids, expression vectors containing multiple isoprenoid biosynthetic genes have been introduced into wild- type and Tri5**- F. sporotrichioides strains. Expression of foreign genes is regulated by Tri5 promoter and terminator sequences through a PCR based cloning strategy. The chimeric genes were then linked together through the use of complementary DraIII/SfiI restriction sites. Preliminary analysis indicates that in several transformants the gene cassettes integrated as intact units within the trichothecene pathway gene cluster. The significance of blocking the trichothecene pathway as a means of increasing foreign isoprenoid pathway gene expression will be tested by comparing the isoprenoid production between wild-type and Tri5**- strains.