Resumen

PEREZ-ROJAS, Fernanda; LEON-QUISPE, Jorge  y  GALINDO-CABELLO, Nadia. Actinoycetes isolated from compost and antagonistic activity against potato phytopathogens (Solanum tuberosum spp. andigena Hawkes). Rev. mex. fitopatol [online]. 2015, vol.33, n.2, pp.116-139. ISSN 2007-8080.

One way of controlling phytopathogens is through the use antagonistic microorganisms. Compost is a source of microorganisms capable of producing secondary metabolites of agricultural interest. We isolated 85 actinomycetes in vitrocultures and evaluated their antagonist capacity against phytopathogens affecting Solanum tuberosum. Of the isolates, 23.5 % showed antagonistic activity against Ralstonia solanacearum, 16.4 % against Pectobacterium carotovorum, 43.5 % against Phytophthora infestans, 25.8 % against Fusarium sp., and 61.1% against Rhizoctonia solani. Organic extracts obtained from the selected strains (AACI-5, ACZI-22, ACZII-35, ACZIII-84 y ACZIII-88) with ethyl acetate and dichloromethane showed antimicrobial activity. The most important was the ethyl acetate extract from the AACI-5 strain, which had a broader spectrum of activity and showed a minimum inhibitory concentration (MIC) against Phytophthora infestans of 0.0625 mg.mL-1. The most active strains were identified as members of the genus Streptomyces. Due to the antagonist capacity showed by actinomycetes in this work, they could be considered as potential candidates for controlling potato pathogens under the framework of sustainable agriculture.

Palabras llave : Streptomyces; bioactive compounds; soil microorganisms; potato pathogens; antagonism.