Antibacterial Activity and Preliminary Phytochemical Screening of Endophytic Fugal Extract of Rauvolfia serpentina

摘要

Endophytic fungi isolated from Rauvolfia serpentina, a well known Indian medicinal plant, is used in Ayurveda for treatment of many diseases. Isolated endophytes were screened for their antibacterial activity against pathogenic bacteria. Twenty fungal isolates were recovered from different parts of the host plant and they were characterized for their morphological features through Scanning Electron Microscopy (SEM) and on the basis of observations they were grouped in eight genus as Fusarium sp., Phomopsis sp., Colletotrichum sp., Cladosporium sp., Aspergillus sp., Xylaria sp., Alterneria sp. and Gleomastix sp. The secret of the fungal endophytes of this medicinal plant was revealed by the evaluation of the extract against the target bacteria. The extracts of four fungal isolates Colletotrichum sp. (Rs-R5), Fusarium sp.(Rs-R1), (Rs-R7) and Cladosporium sp.(Rs-S4) among twenty isolates were found effective against human pathogenic bacterial strains E. coli (ATCC 25922), Gram negative bacteria and S. aureus (ATCC 25323), Gram positive bacteria. Ethyl acetate extract of active fungal isolate (Colletotrichum sp; Rs-R 5) was most effective than other extract, with maximum inhibition zone 16 mm and 14 mm and minimum MIC 25μg/ml and 36.5μg/ml against E. coli and S. aureus respectively.