Catálogo de Investigaciones | 2013-2014

CI ENCIAS 54 Debaryomyces Hansenii Strains, a Biocontrol Alternative, Against Penicillium Digitatum, a Post Harvest Fungus, Affecting Citrus Crops In Puerto Rico Citrus crops contribute 11 million dollars to the Puerto Rican economy. Penicillium spp ., a post-harvest pathogen, infects these crops causing a great economic loss. Debaryomyces hansenii , a marine halotolerant yeast, has the ability to produce a killer toxin which seems to be homologous to the KHR (killer toxin) gene of Saccharomyces cerevisiae whose activity against Penicillium spp . has been reported. In vitro and in vivo studies against the pathogen have been done to determine the antifungal activity of the D. hansenii strains. Screening with YPD-MB plates and inoculating infected oranges with the isolated killer toxin or utilizing whole yeast cells directly, showed that D. hansenii BCS 006 and YB-17914 strains were efficient against Penicillium digitatum . These yeasts strains delayed the growth of the pathogen up to 6 days after exposure. YPD-MB screening assays with D. hansenii strains YB-563, YB-221 and BCS 003 resulted in significant greater inhibition halos than those strains previously reported. Further in vivo studies are being done to correlate the results. D. hansenii’s potential as a biocontrol alternative is promising. stephanie torres y ernesto bárez departamento de biología mentor: dra. hna. nancy arroyo gonzález debaryomyces hansenii penicillium spp