• Home
  • Search Results
  • Anaerobic Chemolithotrophic Growth of the Haloalkaliphilic Bacterium Strain MLMS-1 by Disproportionation of Monothioarsenate.

Anaerobic Chemolithotrophic Growth of the Haloalkaliphilic Bacterium Strain MLMS-1 by Disproportionation of Monothioarsenate.

Environmental science & technology (2015-05-06)
B Planer-Friedrich, C Härtig, R Lohmayer, E Suess, S H McCann, R Oremland
ABSTRACT

A novel chemolithotrophic metabolism based on a mixed arsenic-sulfur species has been discovered for the anaerobic deltaproteobacterium, strain MLMS-1, a haloalkaliphile isolated from Mono Lake, California, U.S. Strain MLMS-1 is the first reported obligate arsenate-respiring chemoautotroph which grows by coupling arsenate reduction to arsenite with the oxidation of sulfide to sulfate. In that pathway the formation of a mixed arsenic-sulfur species was reported. That species was assumed to be monothioarsenite ([H2As(III)S(-II)O2](-)), formed as an intermediate by abiotic reaction of arsenite with sulfide. We now report that this species is monothioarsenate ([HAs(V)S(-II)O3](2-)) as revealed by X-ray absorption spectroscopy. Monothioarsenate forms by abiotic reaction of arsenite with zerovalent sulfur. Monothioarsenate is kinetically stable under a wide range of pH and redox conditions. However, it was metabolized rapidly by strain MLMS-1 when incubated with arsenate. Incubations using monothioarsenate confirmed that strain MLMS-1 was able to grow (μ = 0.017 h(-1)) on this substrate via a disproportionation reaction by oxidizing the thio-group-sulfur (S(-II)) to zerovalent sulfur or sulfate while concurrently reducing the central arsenic atom (As(V)) to arsenite. Monothioarsenate disproportionation could be widespread in nature beyond the already studied arsenic and sulfide rich hot springs and soda lakes where it was discovered.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Methanol, anhydrous, 99.8%
Sigma-Aldrich
Methanol, HPLC Plus, ≥99.9%, poly-coated bottles
Sigma-Aldrich
Methanol, suitable for HPLC, gradient grade, 99.93%
Sigma-Aldrich
Ammonium sulfate, for molecular biology, ≥99.0%
Sigma-Aldrich
Sodium hydroxide solution, BioUltra, for molecular biology, 10 M in H2O
Sigma-Aldrich
Sodium hydroxide solution, 1.0 N, BioReagent, suitable for cell culture
Sigma-Aldrich
Methylene blue, certified by the Biological Stain Commission
Sigma-Aldrich
Sodium (meta)arsenite, ≥90%
Sigma-Aldrich
Sulfur, 99.998% trace metals basis
Sigma-Aldrich
Sulfur, powder, 99.98% trace metals basis
Sigma-Aldrich
Methylene Blue solution, for microscopy, concentrate according to Ehrlich, concentrated, aqueous solution
Sigma-Aldrich
Methyl trifluoromethanesulfonate, ≥98%
Sigma-Aldrich
Ammonium sulfate, BioXtra, ≥99.0%
Sigma-Aldrich
Sodium thiosulfate, ≥99.99% trace metals basis
Sigma-Aldrich
Ammonium sulfate, BioUltra, ≥99.0% (T)
Sigma-Aldrich
Methylene Blue solution, 0.05 wt. % in H2O
Sigma-Aldrich
Sodium hydroxide, BioUltra, for luminescence, ≥98.0% (T), pellets
Sigma-Aldrich
Sodium hydroxide, ultra dry, powder or crystals, 99.99% trace metals basis
Sigma-Aldrich
Ammonium sulfate, 99.999% trace metals basis
Sigma-Aldrich
Sodium thiosulfate solution, 2 g/dL in deionized water
Supelco
Methanol solution, contains 0.10 % (v/v) formic acid, UHPLC, suitable for mass spectrometry (MS), ≥99.5%
Sigma-Aldrich
Methylene Blue solution, 1.4 % (w/v) in 95% ethanol
Sigma-Aldrich
Sulfur, flakes, ≥99.99% trace metals basis
Sigma-Aldrich
Ammonium sulfate, suitable for plant cell culture, ≥99.0%
Sigma-Aldrich
3-Ethyl-2,4-pentanedione, mixture of tautomers, 98%
Sigma-Aldrich
Methanol, NMR reference standard
Sigma-Aldrich
Ammonium-14N2 sulfate, 99.99 atom % 14N
Supelco
Methanol solution, NMR reference standard, 4% in methanol-d4 (99.8 atom % D), NMR tube size 5 mm × 8 in.
Sigma-Aldrich
Methanol solution, NMR reference standard, 4% in methanol-d4 (99.8 atom % D), NMR tube size 3 mm × 8 in.
Supelco
Methanol solution, contains 0.1 % (v/v) trifluoroacetic acid, 5 % (v/v) water, suitable for HPLC