Metabólitos secundários de fungos da Antártica com atividade antibacteriana em Xanthomonas spp.
Carregando...
Arquivos
Data
2018-02-28
Autores
Vieira, Gabrielle [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
As bactérias do gênero Xanthomonas afetam culturas agrícolas de grande importância econômica no Brasil. O controle destas doenças realizado pela utilização de produtos químicos, entre outras práticas, causa impactos negativos na saúde e ao meio ambiente. Isso torna a busca de alternativas sustentáveis de combate a estas doenças cada vez mais importante. Uma possível alternativa aos produtos químicos que tem despertado grande interesse é a aplicação de metabólitos secundários. Suspeita-se que fungos que vivem em ambientes extremos como a Antártica podem produzir metabólitos secundários ainda desconhecidos. Dessa maneira, este projeto teve como objetivo principal investigar a potencial atividade de metabólitos secundários produzidos por 33 fungos isolados do solo contra três espécies de Xanthomonas economicamente importantes para a agricultura do país. Para tanto, foram utilizados fungos coletados em solo em expedição à Antártica (2013) no âmbito do INCT Criosfera, que estão preservados junto à Central de Recursos Microbianos da UNESP. Os extratos (n=66) foram testados contra Xanthomonas patogênicas das culturas de tomate (Xanthomonas euvesicatoria), frutas cítricas (Xanthomonas citri subsp. citri) e maracujá (Xanthomonas axonopodis pv. passiflorae). Do total de extratos brutos submetidos a bioensaio contra os fitopatógenos, 18 (27,27%) apresentaram taxa de inibição ≥ 90%. Os extratos com potencial inibitório tiveram origem em fungos identificados por sequenciamento da região ITS4 e ITS5 como pertencentes ao filo Ascomycota, gênero Pseudogymnoascus. Alguns extratos ativos foram purificados utilizando diversas técnicas cromatográficas por fracionamento bioguiado como cromatografia por exclusão molecular, cromatografia em coluna em fase normal, cromatografia em coluna de fase reversa e cromatografia líquida de alta eficiência por interação hidrofílica. As frações obtidas foram testadas frente à Xanthomonas citri subsp. citri. Duas frações, obtidas por cromatografia líquida de alta eficiência, C2F2 e C2F5 apresentaram atividade inibitória contra o fitopatógeno.
Bacteria of the genus Xanthomonas affect agricultural crops of great economic importance in Brazil. Control of these diseases is made by the use of chemicals, among other practices, that causes negative impacts on human health and the environment. This makes the search for sustainable alternatives to combat these diseases increasingly important. A possible alternative to chemicals that have aroused great interest is the application of secondary metabolites. It is suspected that fungi living in extreme environments such as Antarctica may produce secondary metabolites as of yet unknown. Therefore this study had as main objective investigate the potential activity of secondary metabolites produced by 33 fungi isolated from the soil against three economically important Xanthomonas species. For this purpose fungi previously collected in the Antarctic expedition (2013) under the INCOS Criosfera and preserved at the Microbial Resource Center of UNESP were utillized. The extracts produced by the 33 isolates (n = 66) were tested against pathogenic Xanthomonas of tomato crops: Xanthomonas euvesicatoria; citrus: Xanthomonas citri subsp. citri; and of passion fruit culture, Xanthomonas axonopodis pv. passiflorae. From the total of extracts submitted to bioassay against phytopathogens, 18 (27.27%) presented inhibition rate ≥ 90%. The extracts with inhibitory potential were produced by fungi identified through sequencing of the ITS4 and ITS5 regions as belonging to the Ascomycota phylum, genus Pseudogymnoascus. Some active extracts were purified using chromatography techniques by bioguided fractionation such as solid phase chromatography by molecular exclusion, normal phase column chromatography, reverse phase column chromatography, and high performance liquid chromatography by hydrophilic interaction . The fractions obtained by cromatography were tested for antibacterial activity in Xanthomonas citri subsp. citri. Two fractions, obtained by high performance liquid chromatography, C2F2 and C2F5, showed inhibitory activity against the phytopathogen.
Bacteria of the genus Xanthomonas affect agricultural crops of great economic importance in Brazil. Control of these diseases is made by the use of chemicals, among other practices, that causes negative impacts on human health and the environment. This makes the search for sustainable alternatives to combat these diseases increasingly important. A possible alternative to chemicals that have aroused great interest is the application of secondary metabolites. It is suspected that fungi living in extreme environments such as Antarctica may produce secondary metabolites as of yet unknown. Therefore this study had as main objective investigate the potential activity of secondary metabolites produced by 33 fungi isolated from the soil against three economically important Xanthomonas species. For this purpose fungi previously collected in the Antarctic expedition (2013) under the INCOS Criosfera and preserved at the Microbial Resource Center of UNESP were utillized. The extracts produced by the 33 isolates (n = 66) were tested against pathogenic Xanthomonas of tomato crops: Xanthomonas euvesicatoria; citrus: Xanthomonas citri subsp. citri; and of passion fruit culture, Xanthomonas axonopodis pv. passiflorae. From the total of extracts submitted to bioassay against phytopathogens, 18 (27.27%) presented inhibition rate ≥ 90%. The extracts with inhibitory potential were produced by fungi identified through sequencing of the ITS4 and ITS5 regions as belonging to the Ascomycota phylum, genus Pseudogymnoascus. Some active extracts were purified using chromatography techniques by bioguided fractionation such as solid phase chromatography by molecular exclusion, normal phase column chromatography, reverse phase column chromatography, and high performance liquid chromatography by hydrophilic interaction . The fractions obtained by cromatography were tested for antibacterial activity in Xanthomonas citri subsp. citri. Two fractions, obtained by high performance liquid chromatography, C2F2 and C2F5, showed inhibitory activity against the phytopathogen.
Descrição
Palavras-chave
Cancro cítrico, Mancha-bacteriana, Bacteriose, Atividade antimicrobiana, Fungos filamentosos, Antártica, Citrus canker, Bacterial spot, Passion fruit bacteriosis, Antarctica