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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Microbiol. | doi: 10.3389/fmicb.2019.01960

A Halocin promotes DNA uptake in Haloferax mediterranei

  • 1Anhui Normal University, China
  • 2McMaster University, Canada
  • 3Institute of Microbiology, Chinese Academy of Sciences, China

Halocins are antimicrobial peptides or proteins that are produced by halophilic archaea. Although their function in inhibiting the growth of closely related haloarchaeal strains is well known, other physiological functions of halocins have also been proposed in recent years. To unveil the possible function and mechanism of halocins in DNA uptake, the halocin H4 producing strain Haloferax mediterranei DF50-ΔEPS (incapable of EPS production) was used in this study. We found that deletion of the halH4 resulted in the strain DF50-ΔEPSΔhalH4 which exhibited loss of natural DNA uptake ability. Moreover, supernatants of the halocin producing strain were capable of inducing the ability to uptake DNA. Obviously, halocin is likely responsible for inducing DNA uptake. Cell surface ultrastructures of these strains were varied from strains DF50-ΔEPS to DF50-ΔEPSΔhalH4. The cell surface of strain DF50-ΔEPS was rough due to numerous pinholes, while that of the strain DF50-ΔEPSΔhalH4 was smooth without visible pinholes. The morphology of the halH4 complemented strain, DF50-ΔEPSΔhalH4::H4, showed an intermediate phenotype between strains DF50-ΔEPS and DF50-ΔEPSΔhalH4. We speculate that halocin H4 may accelerate DNA uptake by perforating the cell surface ultrastructure. The halocin H4 may represent a novel inducer or activator of DNA uptake in Hfx. mediterranei.

Keywords: haloarchaea, Halophilic Archaea, DNA uptake, natural transformation, Halocin, Archaeocin

Received: 25 Apr 2019; Accepted: 09 Aug 2019.

Copyright: © 2019 Chen, Sun, Korfanty, Liu and Xiang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
Dr. Shaoxing Chen, Anhui Normal University, Wuhu, China,
Prof. Hua Xiang, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, Beijing Municipality, China,