Nitrate and (per)chlorate reduction pathways in (per)chlorate-reducing bacteria
Oosterkamp, M.J. ; Mehboob, F. ; Schraa, G. ; Plugge, C.M. ; Stams, A.J.M. - \ 2011
Biochemical Society Transactions 39 (2011)1. - ISSN 0300-5127 - p. 230 - 235.
chlorite dismutase - pseudomonas-chloritidismutans - ideonella-dechloratans - chlorate reductase - strain gr-1 - perchlorate reductase - molybdenum cofactor - electron-acceptor - escherichia-coli - 1st step
The reduction of (per)chlorate and nitrate in (per)chlorate-reducing bacteria shows similarities and differences. (Per)chlorate reductase and nitrate reductase both belong to the type II DMSO family of enzymes and have a common bis(molybdopterin guanine dinucleotide)molybdenum cofactor. There are two types of dissimilatory nitrate reductases. With respect to their localization, (per)chlorate reductase is more similar to the dissimilatory periplasmic nitrate reductase. However, the periplasmic, unlike the membrane-bound, respiratory nitrate reductase, is not able to use chlorate. Structurally, (per)chlorate reductase is more similar to respiratory nitrate reductase, since these reductases have analogous subunits encoded by analogous genes. Both periplasmic (per)chlorate reductase and membrane-bound nitrate reductase activities are induced under anoxic conditions in the presence of (per)chlorate and nitrate respectively. During microbial (per)chlorate reduction, molecular oxygen is generated. This is not the case for nitrate reduction, although an atypical reaction in nitrite reduction linked to oxygen formation has been described recently. Microbial oxygen production during reduction of oxyanions may enhance biodegradation of pollutants under anoxic conditions
(Per)chlorate reduction by an acetogenic bacterium, Sporomusa sp., isolated from an underground gas storage
Balk, M. ; Mehboob, F. ; Gelder, A.H. van; Rijpstra, I. ; Sinninghe-Damsté, J.S. ; Stams, A.J.M. - \ 2010
Applied Microbiology and Biotechnology 88 (2010)2. - ISSN 0175-7598 - p. 595 - 603.
sp-nov - homoacetogenic bacterium - strain gr-1 - perchlorate - chlorate - metabolism - water - milk - soil - identification
A mesophilic bacterium, strain An4, was isolated from an underground gas storage reservoir with methanol as substrate and perchlorate as electron acceptor. Cells were Gram-negative, spore-forming, straight to curved rods, 0.5-0.8 microm in diameter, and 2-8 microm in length, growing as single cells or in pairs. The cells grew optimally at 37 degrees C, and the pH optimum was around 7. Strain An4 converted various alcohols, organic acids, fructose, acetoin, and H(2)/CO(2) to acetate, usually as the only product. Succinate was decarboxylated to propionate. The isolate was able to respire with (per)chlorate, nitrate, and CO(2). The G+C content of the DNA was 42.6 mol%. Based on the 16S rRNA gene sequence analysis, strain An4 was most closely related to Sporomusa ovata (98% similarity). The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell-free extracts
Purification and characterization of a chlorite dismutase from Pseudomonas chloritidismutans
Mehboob, F. ; Wolterink, A.F.W.M. ; Vermeulen, A.J. ; Jiang, B. ; Hagedoorn, P.L. ; Stams, A.J.M. ; Kengen, S.W.M. - \ 2009
FEMS Microbiology Letters 293 (2009)1. - ISSN 0378-1097 - p. 115 - 121.
desulfovibrio-vulgaris hildenborough - (per)chlorate-reducing bacteria - strain gr-1 - reductase - catalase
The chlorite dismutase (Cld) of Pseudomonas chloritidismutans was purified from the periplasmic fraction in one step by hydroxyapatite chromatography. The enzyme has a molecular mass of 110 kDa and consists of four 31-kDa subunits. Enzyme catalysis followed Michaelis-Menten kinetics, with Vmax and K(m) values of 443 U mg(-1) and 84 microM, respectively. A pyridine-NaOH-dithionite-reduced Cld revealed a Soret peak at 418 nm, indicative for protoheme IX. The spectral data indicate the presence of 1.5 mol protoheme IX mol(-1) tetrameric enzyme while metal analysis revealed 2.2 mol iron mol(-1) tetrameric enzyme. High concentrations of chlorite resulted in the disappearance of the Soret peak, which coincided with loss in activity. Electron paramagnetic resonance analyses showed an axial high-spin ferric iron signal. Cld was inhibited by cyanide, azide, but not by hydroxylamine or 3-amino-1,2,3-triazole. Remarkably, the activity was drastically enhanced by kosmotropic salts, and chaotropic salts decreased the activity, in accordance with the Hofmeister series. Chlorite conversion in the presence of 18O-labeled water did not result in the formation of oxygen with a mass of 34 (16O-18O) or a mass of 36 ((18)O-(18)O), indicating that water is not a substrate in the reaction and that both oxygen atoms originate from chlorite
(Per)chlorate reduction by the thermophilic bacterium Moorella perchloratireducens sp. nov., isolated from underground gas storage
Balk, M. ; Gelder, A.H. van; Weelink, S.A.B. ; Stams, A.J.M. - \ 2008
Applied and Environmental Microbiology 74 (2008)2. - ISSN 0099-2240 - p. 403 - 409.
clostridium-thermoaceticum - anaerobic bacterium - strain gr-1 - metabolism - chlorate - oxygen - water - identification - purification - tolerance
A thermophilic bacterium, strain An10, was isolated from underground gas storage with methanol as a substrate and perchlorate as an electron acceptor. Cells were gram-positive straight rods, 0.4 to 0.6 µm in diameter and 2 to 8 µm in length, growing as single cells or in pairs. Spores were terminal with a bulged sporangium. The temperature range for growth was 40 to 70°C, with an optimum at 55 to 60°C. The pH optimum was around 7. The salinity range for growth was between 0 and 40 g NaCl liter¿1 with an optimum at 10 g liter¿1. Strain An10 was able to grow on CO, methanol, pyruvate, glucose, fructose, cellobiose, mannose, xylose, and pectin. The isolate was able to respire with (per)chlorate, nitrate, thiosulfate, neutralized Fe(III) complexes, and anthraquinone-2,6-disulfonate. The G+C content of the DNA was 57.6 mol%. On the basis of 16S rRNA analysis, strain An10 was most closely related to Moorella thermoacetica and Moorella thermoautotrophica. The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell extracts. Strain An10 is the first thermophilic and gram-positive bacterium with the ability to use (per)chlorate as a terminal electron acceptor.