ISOLATION AND PRELIMINARY SCREENING OF ENDOPHYTIC FUNGI OF RICINUS COMMUNIS FOR THEIR ANTIMICROBIAL POTENTIAL

摘要

The rapid increase in the antibiotic resistance among the microorganisms led to an everlasting need for new and improved antibiotics and nature serves as a vast source of antimicrobial agents. Present paper deals with the investigation of antimicrobial activity of endophytic fungal isolates obtained from the leaves, stem and beans of Ricinus communis plant against five Gram positive bacteria, two Gram negative bacteria and five fungal pathogens. Agar well diffusion method was used to evaluate the antimicrobial activity of these endophytic fungi. A total of thirty three fungal isolates were obtained from different samples and majority of the isolates (31 out of 33) showed the antimicrobial activity against at least one of the pathogenic microorganisms. Nineteen isolates were found to exhibit broad spectrum antimicrobial activity. The results revealed that 15% endophytic fungal isolates showed antimicrobial activity against Alternaria solani and Bacillus megaterim, 21% against Bacillus subtilis and Candida glabrata, 33% against Candida tropicalis and C. albicans,72% against Escherichia coli, 3% against Fusarium graminearum, 27% against Pseudomonas fluorescens, Staphylococcus aureus and Streptococcus pyogenes and 15% showed bioactivity against Streptococcus mutans. Thus, the results clearly indicate the potential of endophytic fungi isolated from Ricinus communis in the production of pharmaceutical drugs.