Hfq regulates antibacterial antibiotic biosynthesis and extracellular lytic-enzyme production in Lysobacter enzymogenes OH11

Authors

Gaoge Xu, Nanjing Agricultural University
Yuxin Zhao, Nanjing Agricultural University
Liangcheng Du, University of Nebraska-LincolnFollow
Guoliang Qian, Nanjing Agricultural UniversityFollow
Fengquan Liu, Nanjing Agricultural University & Jiangsu Academy of Agricultural ScienceFollow

Date of this Version

2015

Citation

Microbial Biotechnology (2015) 8(3), 499–509 doi:10.1111/1751-7915.12246

Comments

2015 The Authors.

Abstract

Lysobacter enzymogenes is an important biocontrol agent with the ability to produce a variety of lytic enzymes and novel antibiotics. Little is known about their regulatory mechanisms. Understanding these will be helpful for improving biocontrol of crop diseases and potential medical application. In the present study, we generated an hfq (encoding a putative ribonucleic acid chaperone) deletion mutant, and then utilized a new genomic marker-free method to construct an hfq-complemented strain. We showed for the first time that Hfq played a pleiotropic role in regulating the antibacterial antibiotic bio- synthesis and extracellular lytic enzyme activity in L. enzymogenes. Mutation of hfq significantly increased the yield of WAP-8294A2 (an antibacterial antibiotic) as well as the transcription of its key biosynthetic gene, waps1. However, inactivation of hfq almost abolished the extracellular chitinase activity and remarkably decreased the activity of both extracellular protease and cellulase in L. enzymogenes. We further showed that the regulation of hfq in extracellular chitinase production was in part through the impairment of the secretion of chitinase A. Collectively, our results reveal the regulatory roles of hfq in antibiotic metabolite and extracellular lytic enzymes in the underexplored genus of Lysobacter.