Assessment of endophytic fungal isolates for its Antibiofilm activity on Pseudomonas aeruginosa

Abstract

The present study reports assessment of the antibiofilm activity of endophytic fungi on quorum sensing controlled biofilm formation in Pseudomonas aeruginosa MTCC 2453. Endophytic fungi isolated from agriculture field were evaluated for antibiofilm activity. After fermentation in sucrose broth, biofilm formation inhibitors from endophytic fungi were extracted using ethyl acetate. The active extract from each endophytic fungus was assayed for inhibition of biofilm formation using biosensor strain Pseudomonas aeruginosa. At highest tested concentration (200μg/ml) of both fungal extract and biocidal agent, the extract from Fusarium sp.1 demonstrated maximum inhibition in biofilm formation (49.65%) and minimum inhibition by Colletotrichum sp. extract (18.21%) and inhibition was significant at (P < 0.05). Similarly at highest tested concentration (200μg/ml) of fungal extract alone, the maximum percent decrease (18.90%) was observed in P. aeruginosa by Phoma sp. extract and minimum inhibition by Penicillium sp extract (4.00%) with no statistical difference. On the other hand extract from Aspergillus sp.2 was found to show no antibiofilm activity but exhibit stimulatory effect on biofilm formation extract (-4.78%). Combined effect of active fungal extract and biocidal agent resulted in significantly more percent biofilm inhibition as compared to fungal extract alone. The action of one or more active compounds extracted from endophytic fungi may be responsible for antibiofilm activity. Such compounds could be effective against emerging multidrug resistant pathogens. KeywordsEndophytic fungi, Biofilm, Quorum sensing, Pseudomonas aeruginosa.