Medicinal Plants Rhizosphere – A Boon for Inhabiting Antibiotic Producing Microorganisms

Nisha Kashyap¹and Nisha Thakur*^2
1Department of Microbiology, Abhilashi University, Mandi (H.P.) 171005, India
²Department of Biotechnology, Dr. YS Parmar University of Horticulture and Forestry, Solan (H.P) 173212, India

A B S T R A C T
To explore the production of antibiotics from soil microbes residing in the rhizosphere of medicinal plants, a study was carried out at Himachal Pradesh, a hilly state situated in northern Himalayas. Microbes were isolated from the rhizospheric region of three medicinal plants viz., Aloe vera, Mentha and Salvia. Obtained isolates were compared with each other and the isolate having high cfu (colony forming unit) in a particular rhizosphere was selected for further study. For antibiotic sensitivity test (AST) the obtained isolate was clinically screened against three pathogenic microorganisms which were obtained from IGMC (Indira Gandhi Medical College, Shimla) through regular isolations at Cary-Blair transport medium.  These four isolates were identified through morphological and biochemical studies and then were fed into ABIS (Advanced Bacterial Identification Software) which identified these as Bacillus from Aloe vera rhizosphere and 3 other pathogenics as Staphylococcus, Pseudomonas and E.coli. Results obtained during AST were expressed in terms of the diameter of the inhibition zone caused by Bacillus against clinical isolates. Highest zone diameter of 26mm was observed in Pseudomonas followed by Staphylococcus and E.coli
Keywords: rhizosphere, Aloe vera, Mentha and Salvia, Bacillus