ALKANE-GROWTH ADAPTATION OF FUNGI VIRULENT TO TRIATOMA INFESTANS

M. PATRICIA JUÁREZ AND NICOLÁS PEDRINI

Reno, NV, USA

Congreso; Fourth International Congress of Vector Ecology.; 2005

Society of Vector Ecology

ALKANE-GROWTH ADAPTATION OF FUNGI VIRULENT TO TRIATOMA INFESTANS M. Patricia Juárez and Nicolás Pedrini Instituto de Investigaciones Bioquímicas de La Plata (CONICET-UNLP), Facultad de Ciencias Médicas, calles 60 y 120, La Plata, 1900, Argentina. Tel: 54 221 482 4894 int 30 -  Fax: 54 221 425 8988. e-mail: mjuarez@isis.unlp.edu.ar   Alkane-growth adaptation of entomopathogenic fungi shorten the time to kill its insect host, and fungal b-oxidation steps. Virulent strains of Beauveria bassiana were grown on an incubation medium containing insect-like hydrocarbons as the sole carbon source. The time to kill the Chagas disease vector Triatoma infestans was shortened as compared to controls grown in glucose medium. Peroxisome proliferation was reported after alkane-growth induction (Crespo R., M. P. Juárez, and L. F. R Cafferata. 2000. Mycologia 92: 528-536). Correspondingly, the specific activity of catalase, the peroxisomal marker enzyme, increased very significantly for Bb 10 and Bb GHA strains (7.6- to 13.6-fold). An apparent molecular mass of 54.7 kDa was determined for the peroxisomal catalase subunits, after purification to homogeneity by gel filtration and strong anion exchange chromatography. Volatile organic compounds (VOC) released by fungi were analysed by solid phase micro extraction coupled to capillary gas chromatography-mass spectrometry. Decane accounted for almost 95% of the VOC after alkane-growth adaptation, whereas isopropyl methyl naphtalene was the major component detected in control cultures. Measurement of catalase activity is a convenient method for evaluating the efectiveness of the adaptation procedure. Both qualitative and quantitative differences in VOCs profiles might be used as an alternative method to detect fungal adaptation.