Identification and comprehensive evaluation of a novel biocontrol agent Bacillus atrophaeus JZB120050

Abstract

Bacillus spp. have long been used as biocontrol agents because of their efficient broad-spectrum antimicrobial activity. We identified a novel strain of Bacillus atrophaeus, named JZB120050, from soil. B. atrophaeus JZB120050 had a strong inhibitory effect against Botrytis cinerea and many other phytopathogens. Gas chromatography-mass spectrometry showed that B. atrophaeus JZB120050 produced many secondary metabolites, such as alkanes, alkenes and acids; some of which were related to pathogen inhibition. Enzyme activity analysis showed that B. atrophaeus JZB120050 secreted cell-wall-degrading enzymes, including chitinase, glucanase and protease, which degraded fungal cell walls. Both the novel glucanase gene bglu and chitinase gene chit1 were cloned and heterologously expressed in Escherichia coli and the products showed strong enzyme activity. In addition, B. atrophaeus JZB120050 secreted siderophores and formed a significant biofilm. Future studies should focus on these antimicrobial factors to facilitate widespread application in the field of agricultural biocontrol.

Keywords:

• Bacillus atrophaeus
• biocontrol
• secondary metabolites
• cell-wall-degrading enzymes
• heterologous expression

Acknowledgements

We thank Suzhou BioNovoGene Metabolomics Platform for the assistance in GC-MS analysis. We thank International Science Editing (http://www.internationalscienceediting.com) for editing this manuscript. Mi Ni, Qiong Wu, and Junli Wang are co-first authors.

Additional information

Funding

This work was supported by the Beijing Municipal Science and Technology Plan Projects (No. D151100003915002), Special Project for Innovation Ability Construction from the Beijing Academy of Agriculture and Forestry Sciences (No. KJCX20170415), Beijing Agriculture Innovation Consortium (BAIC07-2018), Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North China (No. BZ0432), Science and Technology Innovation Ability Construction Fund from the Beijing Academy of Agriculture and Forestry Sciences (No. KJCX20170107) and Science and Technology Innovation Team of the Beijing Academy of Agriculture and Forestry Sciences (No. JNKST201607).