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Three transcription regulators of the N ss family mediate the adaptive response induced by nitrate, nitric oxide or nitrous oxide in W olinella succinogenes
Author(s) -
Kern Melanie,
Simon Jörg
Publication year - 2016
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.13060
Subject(s) - biology , nitric oxide , nitrate , transcription (linguistics) , microbiology and biotechnology , biochemistry , ecology , endocrinology , linguistics , philosophy
Summary Sensing potential nitrogen‐containing respiratory substrates such as nitrate, nitrite, hydroxylamine, nitric oxide ( NO ) or nitrous oxide ( N 2 O ) in the environment and subsequent upregulation of corresponding catabolic enzymes is essential for many microbial cells. The molecular mechanisms of such adaptive responses are, however, highly diverse in different species. Here, induction of periplasmic nitrate reductase ( N ap), cytochrome c nitrite reductase ( N rf) and cytochrome c N 2 O reductase ( c N os) was investigated in cells of the Epsilonproteobacterium W olinella succinogenes grown either by fumarate, nitrate or N 2 O respiration. Furthermore, fumarate respiration in the presence of various nitrogen compounds or NO ‐releasing chemicals was examined. Upregulation of each of the N ap, N rf and c N os enzyme systems was found in response to the presence of nitrate, NO ‐releasers or N 2 O , and the cells were shown to employ three transcription regulators of the C rp‐ F nr superfamily (homologues of C ampylobacter jejuni NssR ), designated NssA , NssB and NssC , to mediate the upregulation of N ap, N rf and c N os. Analysis of single nss mutants revealed that NssA controls production of the N ap and N rf systems in fumarate‐grown cells, while NssB was required to induce the N ap, N rf and c N os systems specifically in response to NO ‐generators. NssC was indispensable for c N os production under any tested condition. The data indicate dedicated signal transduction routes responsive to nitrate, NO and N 2 O and imply the presence of an N 2 O ‐sensing mechanism.