Abstract
BackgroundThe use of chemical fungicides against fungal pathogens adversely affects soil and plant health thereby resulting in overall environmental hazards. Therefore, biological source for obtaining antifungal agents is considered as an environment-friendly alternative for controlling fungal pathogens.ResultsIn this study, seven endophytic bacteria were isolated from sugarcane leaves and screened for its antifungal activity against 10 fungal isolates belonging to the genera Alternaria, Cochliobolus, Curvularia, Fusarium, Neodeightonia, Phomopsis and Saccharicola isolated from diseased leaves of sugarcane. Among the seven bacterial isolates, SCB-1 showed potent antagonistic activity against the tested fungi. Based on the phenotypic data, Fatty Acid Methyl Esters (FAME) and 16S rRNA gene sequence analysis, the isolate SCB-1 was identified as Bacillus subtilis. The bacterial isolate was screened negative for chitinase production; however, chloroform and methanol extracts of the bacterial culture caused significant inhibition in the growth of the fungal isolates on semisolid media. Volatile component assay showed highest inhibitory activity against Saccharicola bicolor (SC1.4). A PCR based study detected the presence of the genes involved in biosynthesis of surfactin, bacillaene, difficidin, macrolactins and fengycin. Mass spectrometric analysis of the bacterial extract detected the presence of antifungal lipopeptide surfactin, but other metabolites were not detected. The biocontrol activity of the bacterial isolate was established when bacterial pretreated mung bean seeds were able to resist Fusarium infection, however, the untreated seeds failed to germinate.ConclusionThe antifungal potential of isolate Bacillus subtilis SCB-1 was established against taxonomically diverse fungal pathogens including the genera Saccharicola, Cochliobolus, Alternaria and Fusarium. The potent antifungal compound surfactin as well as volatiles produced by the bacterial isolate could be responsible for its bio-control activity against fungal infections.
Highlights
The use of chemical fungicides against fungal pathogens adversely affects soil and plant health thereby resulting in overall environmental hazards
Antagonistic activity of the bacterial isolate against fungal isolates Seven isolates of endophytic bacteria were obtained from healthy sugarcane leaves
Based on the result of Fatty Acid Methyl Esters (FAME) and 16S ribosomal RNA gene sequence analysis, the isolate SCB-1 was identified as Bacillus subtilis
Summary
The use of chemical fungicides against fungal pathogens adversely affects soil and plant health thereby resulting in overall environmental hazards. Biological source for obtaining antifungal agents is considered as an environment-friendly alternative for controlling fungal pathogens. Plant pathogenic microorganisms are a major threat to the stability of agriculture and ecosystem. The course of human history has been altered due to plant disease epidemics triggered by fungi and the fungal-like oomycetes. Irish potato famine killed nearly 1.5 million people, which had ruined the economy of the English government [1, 2]. Fungal phytopathogens are challenging to control because of their diverse host spectra, as well as their soilborne nature [5]. Chemical fungicides are commonly used in higher doses to manage the phytopathogens.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
