Antagonistic activity of cellulose-degrading bacteria isolated from soil and bovine waste against some phytopathogenic fungi

Cellulolytic bacteria can be found in soil and ruminal wastes. The present study was conducted to isolate and identify cellulose degrading bacteria from forest soil and bovine waste and their screening for potential antifungal activity. The cellulolytic bacteria were isolated from the samples by serial dilution method on modified Czapeck (CMC) agar and following Congo red assay. Seventeen isolates were selected on the basis of cellulolytic activity through Congo red assay. The antifungal activity of these isolates was also determined against different phytopathogenic fungi including Alternaria, Cladosporium, Verticillium, Fusarium, Mucor and Rhizopus. The isolates were identified using standard biochemical tests according to Bergey’s manual. Among the ۱۷ isolates, ۱۱ to Bacillus spp., ۲ to Pseudomonas spp., ۱ to Citrobacter spp., ۳ to Staphylococcus spp. belonged. The antifungal activity against the target phytopathogens was shown by the ۲ isolates of Bacillus. Isolate Bacillus spp. R۷ from the bovine waste showed high activity against Alternaria by giving a zone of inhibition of ۱۶ mm while isolate R۱ from the forest soil showed antifungal activity against Fusarium by giving a clear zone of ۱۳ mm. Based on the results of sequencing isolates R۷ and R۱ were most similar (more than ۹۰% identity) to Bacillus licheniformis and Bacillus Subtilis strains, respectively. The results of the present study shows that cellulolytic bacteria are promising for biocontrol of phythopathogens and it is possible to use them as an effective strategy to manage plant diseases and protect the environment.