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BioMed Research International
Volume 2014 (2014), Article ID 465435, 11 pages
http://dx.doi.org/10.1155/2014/465435
Research Article

Control Efficacy of an Endophytic Bacillus amyloliquefaciens Strain BZ6-1 against Peanut Bacterial Wilt, Ralstonia solanacearum

1College of Environmental Science and Engineering, Yangzhou University, Yangzhou 225009, China
2Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing 210095, China
3School of Chemistry and Environmental Engineering, Jiangsu University of Technology, Changzhou 213001, China

Received 30 April 2013; Revised 6 October 2013; Accepted 17 October 2013; Published 12 January 2014

Academic Editor: Daniele Daffonchio

Copyright © 2014 Xiaobing Wang and Guobin Liang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We aimed to isolate and identify endophytic bacteria that might have efficacy against peanut bacterial wilt (BW) caused by Ralstonia solanacearum. Thirty-seven endophytic strains were isolated from healthy peanut plants in R. solanacearum-infested fields and eight showed antagonistic effects against R. solanacearum. Strain BZ6-1 with the highest antimicrobial activity was identified as Bacillus amyloliquefaciens based on morphology, biochemistry, and 16S rRNA analysis. Culture conditions of BZ6-1 were optimized using orthogonal test method and inhibitory zone diameter in dual culture plate assay reached 34.2 mm. Furthermore, main antimicrobial substances of surfactin and fengycin A homologues produced by BZ6-1 were analyzed by high performance liquid chromatography electrospray ionization tandem mass spectrometry. Finally, pot experiments were adopted to test the control efficiency of BZ6-1 against peanut BW. Disease incidence decreased significantly from 84.5% in the control to 12.1% with addition of 15 mL (108 cfu mL−1) culture broth for each seedling, suggesting the feasibility of strain BZ6-1 in the biological control of peanut plants BW.