Screening and Identification of Cellulolytic Bacteria from Organic Waste for Antifungal Applications

Municipal solid waste and related organic residues contain lignocellulosic materials that support the growth of cellulose-degrading microorganisms. In the present study, cellulolytic bacteria were isolated from organic waste collected from different locations in Dal Lake and the SKUAST-K Shalimar campus, Srinagar, and their antifungal activity was evaluated under in vitro conditions. A total of 27 samples representing agricultural waste, aquatic weeds and kitchen waste were processed through serial dilution and cultured on nutrient agar. The isolates were subsequently screened for cellulolytic activity on carboxymethyl cellulose agar using Congo red staining. Twenty-eight cellulolytic bacterial isolates were obtained, of which five isolates showing the highest zones of hydrolysis were selected for further study. These isolates, designated CB1, CB2, CB3, CB4 and CB5, were characterised using colony morphology, Gram staining and biochemical tests. All selected isolates were Gram-positive, rod-shaped and catalase-positive, and were tentatively identified as belonging to the genus Bacillus. Their antagonistic activity was tested against Fusarium oxysporum and Venturia inaequalis. All five isolates inhibited the growth of both fungal pathogens. Against Fusarium oxysporum, inhibition ranged from 33.35% to 61.02%, with isolate CB2 showing the highest inhibition. Against Venturia inaequalis, inhibition ranged from 14.6% to 21.34%, and CB2 again showed the highest inhibition. The findings indicate that organic waste can serve as a source of cellulolytic bacterial isolates with measurable antifungal activity under laboratory conditions. These isolates may be useful for further evaluation in cellulose degradation and preliminary biocontrol studies, although their field-level performance requires validation through additional targeted testing under controlled conditions.