Peptaibols from Trichoderma asperellum TR356 strain isolated from Brazilian soil.
The Trichoderma genus consists of a group of free-living filamentous fungi, including species able to act as biological control agents (BCAs) against pathogenic fungi. It is believed that this ability is due to synergy between several mechanisms, including the production of a wide variety of secondary metabolites by these organisms. Among these, we highlight the production of peptaibols, an antibiotic peptide group characterized by the presence of non-proteinogenic amino acids such as α-aminoisobutyrate (Aib), as well as by N-terminal modifications and amino alcohols in the C-terminal region. This study aimed to outline a profile of peptaibol production and to identify secreted peptaibols from the Trichoderma asperellum TR356 strain, described as an efficient BCA against S. sclerotiorum. The fungus was grown on TLE 0.3% glucose medium for 5 days, with agitation at 120 rpm in the dark. Liquid medium filtrate was used as the metabolite source. These extracts were subjected to high performance liquid chromatography (HPLC) and subsequent analysis by matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF). The results indicate the production of two classes of peptaibols for this T. asperellum strain. Primary structures of two asperelines (A and E) and five trichotoxins (T5D2, T5E, T5F, T5G and 1717A) have been elucidated. Most of these peptaibols had been previously described in T. viride and T. asperellum marine strains. This is the first report of some of these compounds being produced by a T. asperellum strain from soil. Future analyses will be necessary to elucidate the three-dimensional structures and their activities against pathogens.
Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Goiás (ICB II), 74001-970 Goiânia, GO Brasil.
João Pc
JP
Brito
Empresa Brasileira de Pesquisa Agropecuária, Centro Nacional de Pesquisa de Recursos Genéticos e Biotecnologia, PBI. Parque Estação Biológica, Asa Norte, 70910-90 Brasília, DF Brasil.
Marcelo Hs
MH
Ramada
Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center - Uconn Health Center, 263 Farmington Avenue, Farmington, CT 06030 USA.
Mariana Tq
MT
de Magalhães
Empresa Brasileira de Pesquisa Agropecuária, Centro Nacional de Pesquisa de Recursos Genéticos e Biotecnologia, PBI. Parque Estação Biológica, Asa Norte, 70910-90 Brasília, DF Brasil.
Luciano P
LP
Silva
Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Goiás (ICB II), 74001-970 Goiânia, GO Brasil.
Cirano J
CJ
Ulhoa
Asperelines; Mass spectrometry; Peptaibols; Trichoderma asperellum; Trichotoxins