Perchlorate and chlorate reduction by the Crenarchaeon Aeropyrum pernix and two thermophilic Firmicutes.
This study reports the ability of one hyperthermophilic and two thermophilic microorganisms to grow anaerobically by the reduction of chlorate and perchlorate. Physiological, genomic and proteome analyses suggest that the Crenarchaeon Aeropyrum pernix reduces perchlorate with a periplasmic enzyme related to nitrate reductases, but that it lacks a functional chlorite-disproportionating enzyme (Cld) to complete the pathway. Aeropyrum pernix, previously described as a strictly aerobic microorganism, seems to rely on the chemical reactivity of reduced sulfur compounds with chlorite, a mechanism previously reported for perchlorate-reducing Archaeoglobus fulgidus. The chemical oxidation of thiosulfate (in excessive amounts present in the medium) and the reduction of chlorite result in the release of sulfate and chloride, which are the products of a biotic-abiotic perchlorate reduction pathway in Ae. pernix. The apparent absence of Cld in two other perchlorate-reducing microorganisms, Carboxydothermus hydrogenoformans and Moorella glycerini strain NMP, and their dependence on sulfide for perchlorate reduction is consistent with the observations made on Ar. fulgidus. Our findings suggest that microbial perchlorate reduction at high temperature differs notably from the physiology of perchlorate- and chlorate-reducing mesophiles and that it is characterized by the lack of a chlorite dismutase and is enabled by a combination of biotic and abiotic reactions.
Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands.
Martin G
MG
Liebensteiner
Analytical Biotechnology Section, Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC, Delft, The Netherlands.|Netherlands Proteomics Centre, Julianalaan 67, 2628 BC, Delft, The Netherlands.
Martijn W H
MW
Pinkse
Laboratory of Systems and Synthetic Biology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands.
Bart
B
Nijsse
Analytical Biotechnology Section, Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC, Delft, The Netherlands.|Netherlands Proteomics Centre, Julianalaan 67, 2628 BC, Delft, The Netherlands.
Peter D E M
PD
Verhaert
Shell International Exploration and Production Inc., 3333 Highway 6 South, Houston, TX, 77082, USA.
Nicolas
N
Tsesmetzis
Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands.|Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
Alfons J M
AJ
Stams
Shell Global Solutions International B.V., Kessler Park 1, 2288 GS, Rijswijk, The Netherlands.
Bart P
BP
Lomans
D041522:Aeropyrum / Q000235:genetics / Q000378:metabolism*; D002704:Chlorates / Q000378:metabolism*; D000068536:Bacillota / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D010472:Perchlorates / Q000378:metabolism*; D020543:Proteome; D013885:Thiosulfates / Q000378:metabolism
D002704:Chlorates; D010472:Perchlorates; D020543:Proteome; D013885:Thiosulfates; D010088:Oxidoreductases; C402794:chlorite dismutase; C494474:perchlorate