The metabolic impact of extracellular nitrite on aerobic metabolism of Paracoccus denitrificans

WATER RESEARCH

卷:113

Article

Hartop, K. R.¹  Sullivan, M. J.¹  Giannopoulos, G.¹  Gates, A. J.¹  Bond, P. L.²  Yuan, Z.²  Clarke, T. A.¹  Rowley, G.¹  Richardson, D. J.¹ 

[1] Univ East Anglia, Sch Biol Sci, Norwich NR4 7TJ, Norfolk, England

[2] Univ Queensland, Adv Water Management Ctr, St Lucia, Qld 4072, Australia

关键词: Nitrite;    Free nitrous acid;    Denitrification;    Paracoccus denitrificans;    Nitrosative stress;    Reactive nitrogen species;    Flavohemoglobin;    Nitric oxide;   

DOI  :  10.1016/j.watres.2017.02.011

来源: Elsevier

【 摘 要 】

Nitrite, in equilibrium with free nitrous acid (FNA), can inhibit both aerobic and anaerobic growth of microbial communities through bactericidal activities that have considerable potential for control of microbial growth in a range of water systems. There has been much focus on the effect of nitrite/FNA on anaerobic metabolism and so, to enhance understanding of the metabolic impact of nitrite/FNA on aerobic metabolism, a study was undertaken with a model denitrifying bacterium Paracoccus denitrificans PD1222. Extracellular nitrite inhibits aerobic growth of P. denitrificans in a pH-dependent manner that is likely to be a result of both nitrite and free nitrous acid (pKa = 3.25) and subsequent reactive nitrogen oxides generated from the intracellular passage of FNA into P. denitrificans. Increased expression of a gene encoding a flavohemoglobin protein (Fhp) (Pden_1689) was observed in response to extracellular nitrite. Construction and analysis of a deletion mutant established Fhp to be involved in endowing nitrite/FNA resistance at high extracellular nitrite concentrations. Global transcriptional analysis confirmed nitrite-dependent expression of flip and indicated that P. denitrificans expressed a number of stress response systems associated with protein, DNA and lipid repair. It is therefore suggested that nitrite causes a pH-dependent stress response that is due to the production of associated reactive nitrogen species, such as nitric oxide from the internalisation of FNA. (C) 2017 The Authors. Published by Elsevier Ltd.

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