RESUMO
This study evaluated the quaternary ammonium compound cetyl trimethyl ammonium bromide (CTAB) as an alternative to the chemically related dodecylguanidine (dodine) for the selective isolation of entomopathogenic fungi. Oatmeal agar (OA) with chloramphenicol was used as basal medium, and three concentrations of CTAB (0.5, 0.6, 0.7 g/L) were evaluated and compared against OA + 0.46 g/L dodine. Selective isolation and growth studies were performed with the entomopathogens Beauveria bassiana, Metarhizium anisopliae s.l. and Paecilomyces lilacinus and five common non-entomopathogenic non-target species. The three entomopathogenic fungi sporulated earlier on OA + 0.6 g/L CTAB than on OA + 0.46 g/L dodine, while none of the non-target fungi sporulated on OA + 0.6 g/L CTAB. All entomopathogenic fungal isolates grew on OA + 0.6 g/L CTAB, despite some intra-species variation, whereas non-target fungi showed no growth or sporulation. OA + 0.6 g/L CTAB resulted in an efficient medium to isolate B. bassiana, M. anisopliae s. l. and P. lilacinus from soil samples. Results of our study suggest that OA + 0.6 g/L CTAB is a suitable, simple and inexpensive to prepare medium to replace OA + 0.46 g/L dodine for the selective isolation of these fungi.
Assuntos
Beauveria/isolamento & purificação , Compostos de Cetrimônio/metabolismo , Metarhizium/isolamento & purificação , Paecilomyces/isolamento & purificação , Microbiologia do Solo , Avena/metabolismo , Beauveria/efeitos dos fármacos , Beauveria/crescimento & desenvolvimento , Beauveria/metabolismo , Cetrimônio , Cloranfenicol/metabolismo , Contagem de Colônia Microbiana , Meios de Cultura/metabolismo , Farmacorresistência Fúngica , Fungicidas Industriais/metabolismo , Fungicidas Industriais/farmacologia , Guanidinas/metabolismo , Guanidinas/farmacologia , Metarhizium/efeitos dos fármacos , Metarhizium/crescimento & desenvolvimento , Metarhizium/metabolismo , Testes de Sensibilidade Microbiana , Paecilomyces/crescimento & desenvolvimento , Paecilomyces/metabolismo , Fatores de TempoRESUMO
Five fungal species were isolated and identified in food products: Ascotricha chartarum, Leptosphaerulina argentinensis, Veronaea coprophila, Scolecobasidium constrictum and Coremiella cubispora. A. chartarum was isolated from paper bag containing sugar and the other four from tomato sauce. Except for L. argentinensis, the other four were new reports and the five species were isolated for the first time in Argentina.