Arsenic(III) Fuels Anoxygenic Photosynthesis in Hot Spring Biofilms from Mono Lake, California

  title={Arsenic(III) Fuels Anoxygenic Photosynthesis in Hot Spring Biofilms from Mono Lake, California},
  author={Thomas R. Kulp and Shelley E. Hoeft and Marie Asao and Michael T. Madigan and James Timothy Hollibaugh and Jenny C. Fisher and John F. Stolz and Charles W. Culbertson and Laurence G Miller and Ronald S. Oremland},
  pages={967 - 970}
Phylogenetic analysis indicates that microbial arsenic metabolism is ancient and probably extends back to the primordial Earth. In microbial biofilms growing on the rock surfaces of anoxic brine pools fed by hot springs containing arsenite and sulfide at high concentrations, we discovered light-dependent oxidation of arsenite [As(III)] to arsenate [As(V)] occurring under anoxic conditions. The communities were composed primarily of Ectothiorhodospira-like purple bacteria or Oscillatoria-like… 
Coupled Arsenotrophy in a Hot Spring Photosynthetic Biofilm at Mono Lake, California
Interestingly, no authentic PCR products for arsenite oxidase (aoxB) were obtained, despite observing aerobic arsenite oxidation activity, which demonstrates close linkages of these arsenic redox processes occurring within these biofilms.
Autotrophic microbial arsenotrophy in arsenic-rich soda lakes.
What has been learned by investigations undertaken in three soda lakes of the western USA and from the physiological characterizations of the relevant bacteria is reviewed, which include the critical genes involved, such as respiratory arsenate reductase (arrA) and the discovery of its arsenite-oxidizing counterpart (arxA).
Comment on "Arsenic (III) Fuels Anoxygenic Photosynthesis in Hot Spring Biofilms from Mono Lake, California"
This work challenges the proposition that As(V) reductase was responsible for the anaerobic oxidation of As(III) in the Archean based on paleogeochemical, bioenergetic, and phylogenetic arguments.
Environmental Microbiology: Arsenic in action
The findings suggest that the history of prokaryotic arsenate respiration should be re-evaluated and that organisms in other environments, such as the hot springs of Yellowstone National Park, United States, may also be able to carry out the anoxygenic oxidation of As(III) to As(V), thereby broadening the ecological importance of this phenomenon.
The genetic basis of anoxygenic photosynthetic arsenite oxidation
The role of arxA in photosynthetic arsenite oxidation was confirmed by disrupting the gene in a representative photoarsenotrophic bacterium, resulting in the loss of light-dependent arsenites oxidation.
Biotransformation of arsenic by a Yellowstone thermoacidophilic eukaryotic alga
The importance of eukaryotic microorganisms to the biogeochemical cycling of arsenic in geothermal systems is illustrated, a molecular explanation for how these algae tolerate arsenic in their environment is offered, and the characterization of algal methyltransferases is provided.
Metagenomic study of red biofilms from Diamante Lake reveals ancient arsenic bioenergetics in haloarchaea
The discovery of haloarchaea (Euryarchaeota phylum) biofilms forming under the extreme environmental conditions such as high salinity, pH and arsenic concentration at 4589 m above sea level inside a volcano crater in Diamante Lake, Argentina is reported.
Anoxygenic photosynthesis and iron–sulfur metabolic potential of Chlorobia populations from seasonally anoxic Boreal Shield lakes
The results provide an important basis for further probing the functional role of cyc2 and indicate that anoxygenic photoautotrophs in Boreal Shield lakes could have underexplored photophysiology pertinent to understanding Earth’s early microbial communities.
Microbiological Oxidation of Antimony(III) with Oxygen or Nitrate by Bacteria Isolated from Contaminated Mine Sediments
The results suggest that expression of aioA is not induced by Sb(III) but may be involved in Sb (III) oxidation along with an SB(III)-specific pathway.
Microbiology of inorganic arsenic: From metabolism to bioremediation.


A Microbial Arsenic Cycle in a Salt-Saturated, Extreme Environment
Searles Lake is a salt-saturated, alkaline brine unusually rich in the toxic element arsenic, and a full biogeochemical cycle of arsenic occurs in Searles Lake, driven in part by inorganic electron donors.
A New Chemolithoautotrophic Arsenite-Oxidizing Bacterium Isolated from a Gold Mine: Phylogenetic, Physiological, and Preliminary Biochemical Studies
This recently discovered organism is the most rapidly growing chemolithoautotrophic arsenite oxidizer known and may represent a new species.
Arsenite-dependent photoautotrophy by an Ectothiorhodospira-dominated consortium
The list of compounds known to support anoxygenic photosynthesis is extended and a previously unknown pathway in arsenic geochemistry is Documented, adding to the number of bacteria shown to obtain energy for growth through redox transformations of arsenic.
The arsenite oxidase genes (aroAB) in novel chemoautotrophic arsenite oxidizers.
2-Methylhopanoids as biomarkers for cyanobacterial oxygenic photosynthesis
It is shown that 2-methylbacteriohopanepolyols occur in a high proportion of cultured cyanob bacteria and cyanobacterial mats and are abundant in organic-rich sediments as old as 2,500 Myr, which may help constrain the age of the oldest cyanobacteria and the advent of oxygenic photosynthesis.
Autecology of an Arsenite Chemolithotroph: Sulfide Constraints on Function and Distribution in a Geothermal Spring
It is illustrated that H2S is a potent inhibitor of As(III) oxidation and will influence the niche opportunities and population distribution of As (III) chemolithotrophs.
Anoxygenic microbial mats of hot springs: thermophilic Chlorobium sp
Non-laminated, green to yellow-green microbial mats, with Chlorobium sp. as the only phototroph, occurred from 55 to about 40°C in hot springs in and near Rotorua, New Zealand. The pH ranged from 4.3
A likely role for anoxygenic photosynthetic microbes in the formation of ancient stromatolites
The appreciable stimulation of the growth of proto-lamina by a nonfilamentous anoxygenic microbe suggests that similar microbes may have played a greater role in the formation of Archean stromatolites than previously assumed.
Alkalilimnicola ehrlichii sp. nov., a novel, arsenite-oxidizing haloalkaliphilic gammaproteobacterium capable of chemoautotrophic or heterotrophic growth with nitrate or oxygen as the electron acceptor.
On the basis of physiological characteristics and DNA-DNA hybridization data, it is suggested that strain MLHE-1(T) represents a novel species within the genus Alkalilimnicola for which the name Alkalspirillum mobile ehrlichii is proposed.
Anaerobic oxidation of ferrous iron by purple bacteria, a new type of phototrophic metabolism
Anoxic iron-rich sediment samples that had been stored in the light showed development of brown, rusty patches and the existence of ferrous iron-oxidizing anoxygenic phototrophic bacteria may offer an explanation for the deposition of early banded-iron formations in an assumed anoxic biosphere in Archean times.