Open AccessCo‐localization of particulate methane monooxygenase and cd 1 nitrite reductase in the denitrifying methanotroph ‘ C andidatus M ethylomirabilis oxyfera’
Author(s) -
Wu Ming L.,
Alen Theo A.,
Donselaar Elly G.,
Strous Marc,
Jetten Mike S.M.,
Niftrik Laura
Publication year - 2012
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2012.02615.x
Subject(s) - methanotroph , methane monooxygenase , anaerobic oxidation of methane , nitrite reductase , denitrifying bacteria , periplasmic space , monooxygenase , biochemistry , oxygenase , biology , candidatus , nitrite , nitrous oxide reductase , chemistry , carbon monoxide dehydrogenase , denitrification , enzyme , escherichia coli , genome , gene , carbon monoxide , nitrate reductase , nitrate , cytochrome p450 , ecology , organic chemistry , nitrogen , catalysis
‘ C andidatus M ethylomirabilis oxyfera’; is a polygon‐shaped bacterium that was shown to have the unique ability to couple anaerobic methane oxidation to denitrification, through a newly discovered intra‐aerobic pathway. Recently, the complete genome of M ethylomirabilis oxyfera was assembled into a 2.7‐Mb circular single chromosome by metagenomic sequencing. The genome of M . oxyfera revealed the full potential to perform both methane oxidation and the conversion of nitrite via nitric oxide into oxygen and dinitrogen gas. In this study, we show by immunogold localization that key enzymes from both methane‐ and nitrite‐converting pathways are indeed present in single M . oxyfera cells. Antisera targeting the particulate methane monooxygenase (p MMO ) and the cd 1 nitrite reductase ( N ir S ) were raised and used for immunogold localization in both single‐ and double‐labelling experiments. Our previous studies have shown that M . oxyfera does not develop p MMO ‐containing intracytoplasmic membranes as is observed in classical proteobacterial methanotrophs. Our results suggest that in M . oxyfera , the p MMO and N ir S enzymes localized to the cytoplasmic membrane and periplasm, respectively. Further, double‐labelling showed co‐occurrence of p MMO and N ir S in single M . oxyfera cells.