Journal of Pure and Applied MicrobiologyVol. 8 No. May 2014 Special Edition

Isolation and Characterization of an Endophytic Bacillus subtilis Displaying Antibacterial and Anticancer Activities from Dioscorea zingiberensis C. H. Wright Rhizome

Zhixiong Jin1, 2, Wei Zhou2, Wenqin Wu3 and Yongji Wan2*

1Dong Fen Hospital, Hu Bei University of Medicine, Hubei 442000, China. 2Laboratory of Applied Microbiology, College of Biotechnology, Southwest University, Chongqing - 400715, China. 3Tai He Hospital, Hu Bei University of Medicine, Hubei 442000, China.

Received on 12 April 2014 and accepted on 09 May 2014



Dioscorea zingiberensis C. H. Wright is an important medicinal plant. We have firstly isolated several bacteria strains from the inner tissues of D. zingiberensis rhizome. One of them was named as SWB8 and identified as Bacillus subtilis via 16S rDNA analysis. Strain SWB8 is a Gram-positive spore-forming rod, aerobe or facultative aerobe with high salt and high alkali tolerance (pH 9.0, 9.0% NaCl), possessing a novel characteristic of the single chain fruiting body and produces several enzymes. The protein extract (PE) of strain SWB8 fermenting liquor showed inhibition effect against all six tested human pathogenic bacteria strains (Staphylococcus aureus; Enterococcus faecalis; Escherichia coli; Salmonella typhi; Salmonella paratyphi A; Shigella dysenteriae). The PE possessed significant anticancer activity against human pulmonary adenocarcinoma cells (A549) that the IC50 and IC90 values were 11.3 and 18.6 ?g ml-1, respectively. In contrast, human bone marrow mesenchymal stem cells (MSCs) showed high survivability with the IC50 value of 26.4?g ml-1. B. subtilis SWB8 could be a potential source of antimicrobial agent or anticancer compounds with higher efficiency and lower toxicity.

Keywords : Dioscorea zingiberensis C. H. Wright, Endophyte, Bacillus subtilis, Activity.