Nazir Ahmad Wani1, Waseem Iqbal Khanday2, Sharmila Tirumale1
1Department of Microbiology and Biotechnology, Bangalore University, Bengaluru, Karnataka, India.
2PG and Research Centre in Biotechnology, MGR College, Hosur, Tamil Nadu, India.
Background: Chaetomium cupreum is soil-isolated pigment-producing fungus used as biocontrol agent. Hypothesis: The aim of the present study was to evaluate the bioactive constituents and antibacterial potential of C. cupreum extracts on bacteria such as Staphylococcus aureus, Bacillus subtilis, Salmonella typhi, and Proteus vulgaris. Materials and Methods: The qualitative and quantitative screening of secondary metabolites was done by standard procedures. The antibacterial activity of different extracts of C. cupreum was determined by agar well diffusion method and broth microdilution methods. Results: Among the different extracts of C. cupreum, ethyl acetate and n-butanol extracts exhibited antibacterial activity. In the n-butanol extract, the most susceptible organism was found to be B. subtilis with zone of inhibition 18.5 ± 0.7 mm, followed by P. vulgaris 15.5 ± 0.7 mm, S. typhi 12.5 ± 3.5 mm, and S. aureus 12.0 ± 2.8 mm at 0.5 mg/ml, whereas in the ethyl acetate extract, the most susceptible organism was to found be P. vulgaris with zone of inhibition 17.5 ± 0.7 mm followed by B. subtilis 17.0 ± 1.4 mm, S. typhi 14.0 ± 0.7 mm, and S. aureus 13.5 ± 0.7 mm at 0.5 mg/ml. Conclusion: The obtained results suggest that C. cupreum extracts contain compounds that possess antibacterial activity.
Keywords: Azaphilones, bacteremia, bacterial infections, biopigments, Chaetomium cupreum, metabolites, resistance.