Applied Microbiology and Biotechnology

, Volume 97, Issue 19, pp 8823–8830 | Cite as

Enhanced root colonization and biocontrol activity of Bacillus amyloliquefaciens SQR9 by abrB gene disruption

  • Jun Weng
  • Yang Wang
  • Juan Li
  • Qirong Shen
  • Ruifu ZhangEmail author
Environmental biotechnology


Root colonization by antagonistic bacteria is a prerequisite for successful biological control, and the instability of colonization under varying environmental conditions has accentuated the need to improve the colonization activity. Root colonization by Bacillus spp. is mainly determined by chemotaxis and biofilm formation, and both functions are negatively controlled by the global transcription regulator AbrB. Here, we disrupted the gene abrB in Bacillus amyloliquefaciens SQR9, which has been proven to be a promising biocontrol agent of cucumber and watermelon wilt disease. Chemotaxis, biofilm formation, and colonization activities as well as biocontrol efficiency were measured and compared between the wild-type strain of SQR9 and the abrB mutant. The data presented in this article demonstrate that the colonization and biocontrol activity of B. amyloliquefaciens SQR9 could be significantly improved by abrB gene disruption. The results offer a new strategy to enhance the biocontrol efficacy of B. amyloliquefaciens SQR9.


Bacillus amyloliquefaciens Root colonization Chemotaxis Biofilm AbrB Biocontrol 



This research was financially supported by National Natural Science Foundation of China (41271271) and the Chinese Ministry of Science and Technology (2011BAD11B03), and R.Z. and Q.S. were also supported by the 111 Project (no. B12009) and the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Jun Weng
    • 1
    • 2
  • Yang Wang
    • 1
    • 2
  • Juan Li
    • 1
    • 2
  • Qirong Shen
    • 1
    • 2
  • Ruifu Zhang
    • 1
    • 2
    Email author
  1. 1.Jiangsu Key Lab for Solid Organic Waste UtilizationCollege of Resources and Environmental Science, Nanjing Agricultural UniversityNanjingChina
  2. 2.Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjingChina

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