MYCOCIDAL ACTIVITY OF CRUDE EXTRACTS OF MARINE-DERIVED BENEFICIAL FUNGI AGAINST PLANT PATHOGENIC FUNGI

Abstract

The ethyl acetate (EtOAc) crude extracts of five marine-derived fungi, namely Emericella nidulans (KUFA 0104), Hamigera avellanea (KUFA 0106), Neosartorya fischeri (KUFA 0107), N. pseudofischeri (KUFA 0108) and Talaromyces trachyspermus (KUFA 0021), were evaluated for their in vitro antifungal activity against ten economically important plant pathogenic fungi. The crude extract of Talaromyces trachyspermus (KUFA 0021) exhibited the most effective mycelial growth inhibition in most of the plant pathogenic fungi whereas the rest of the crude extracts displayed relevant antifungal properties against the tested plant pathogenic fungi. The EtOAc crude extract of T. trachyspermus (KUFA 0021) was found to effectively inhibit the mycelial growth of Alternaria brassicicola, Colletotrichum capsici, Helminthosporium maydis, Pythium aphanidermatum, Rhizoctonia solani and Sclerotium rolfsii with IC50 values 100-186 ppm and IC90 values 205-807 ppm and displayed total inhibition of mycelial growth on all plant pathogenic fungi at the highest concentration tested (10,000 ppm). Interestingly, this extract was effective on the mycelial growth inhibition of P. aphanidermatum even at low concentration with have IC50 and IC90 values 100 and 205 ppm, respectively. Chemical investigation of the EtOAc crude extract of the culture of T.trachyspermus (KUFA 0021) resulted in theisolation of spiculisporic acid E, 3- acetylergosterol 5, 8- endoperoxide,ergosta- 4,6,8 (14), 22- tetraen- 3- one, glaucanic acid and glauconic acid. Spiculisporic acid E, glaucanic acid, glauconic acid and the combination of these compounds were tested for the antifungal activity and it was found that none of them was active against the tested plant pathogens.