Antagonistic activity and Biofilm studies on Streptomyces species towards Nigrospora sp

摘要

Plants, in contrast with vertebrates, have no immune system. So they are affected by pathogens easily leading to remarkable yield loss altogether. Fungal phytopathogens pose serious problems worldwide in the agriculture sector, and harmful and costly chemical fungicides are nowhere a match to them. A detailed study was performed to screen the cooperative role of Streptomyces coelicolor and Streptomyces halstedii towards the fungal pathogen Nigrospora, a predominant pathogen of banana plantation. Many works were published stating the antagonistic activity of the Streptomyces species. For the first time we tried to study against the Nigrospora, which is a predominant pathogen of banana plant. Moreover we tried to find out the cooperative role of both the species towards the fungal pathogen. Biofilm formation studies were done using the ethanol method, and Chitinase activity was quantified using DNS method. Free radical scavenging activity was quantified using the standard DPPH method. The antioxidant profiles were screened using the TLC plate in mobile phase (5:4:3 (v/v/v) n-butanol/Methanol/16% aqueous ammonia). The antagonistic screening test done using the cup plate method proved the cooperative role of both the species. The activity of chitinase was observed for all the groups. Both the species showed chitinase activity, but when they are co cultured the activity was found to be enhanced. Even the co culture study also proved of the strong biofilm formation. Previous literature also showed of the exhibition of biofilm formation of the Streptomyces species. The increase or stability in the values proves of the possible cooperative role of both the species in the antagonistic activity against the Nigrospora species. A one way ANOVA was done to show the significance in the formation of biofilms. Peculiar results were obtained in the TLC. The Rf values obtained were compared with the standard antioxidant Rf values. The Rf values of 0.12 match with the catechin, and 0.4 match with the Quercetin, 06 match with Caffeic acid.