Cohn’s Crenothrix is a filamentous methane oxidizer with an unusual methane monooxygenase

doi:10.1073/pnas.0506361103

Cohn’s Crenothrix is a filamentous methane oxidizer with an unusual methane monooxygenase

*Department für Mikrobielle Ökologie, Universität Wien, A-1090 Wien, Austria;
^†Deutsche Vereinigung des Gas- und Wasserfaches-Forschungsstelle, Technische Universität Hamburg, D-21073 Hamburg, Germany; and
^‡Department of Life Sciences, Aalborg University, DK-9000 Aalborg, Denmark

Edited by James M. Tiedje, Michigan State University, East Lansing, MI, and approved December 19, 2005 (received for review July 26, 2005)

Abstract

135 years ago Ferdinand Cohn, the founder of bacteriology, microscopically observed a conspicuous filamentous bacterium with a complex life cycle and described it as Crenothrix polyspora. This uncultured bacterium is infamous for mass developments in drinking water systems, but its phylogeny and physiology remained unknown. We show that C. polyspora is a gammaproteobacterium closely related to methanotrophs and capable of oxidizing methane. We discovered that C. polyspora encodes a phylogenetically very unusual particulate methane monooxygenase whose expression is strongly increased in the presence of methane. Our findings demonstrate a previously unrecognized complexity of the evolutionary history and cell biology of methane-oxidizing bacteria.

Footnotes

^§To whom correspondence should be addressed at:
Department for Mikrobielle Ökologie, Universität Wien, Althanstrasse 14, A-1090 Wien, Austria.
E-mail: wagner{at}microbial-ecology.net
Author contributions: H.D. and M.W. designed research; K.S., B.B., B.S., P.H.N., J.L.N., C.B., E.R.T., and H.D. performed research; K.S., B.B., C.B., H.D., and M.W. analyzed data; and M.W. wrote the paper.
Conflict of interest statement: No conflicts declared.
This paper was submitted directly (Track II) to the PNAS office.
Data deposition: The DNA sequences reported in this work have been deposited in the GenBank database (accession nos. DQ295887–DQ295913).
Abbreviations:

Abbreviations:

MAR,

microautoradiography;

Q-PCR,

quantitative PCR.
Freely available online through the PNAS open access option.