CARBON FIXATION Cyanobacteria use the reducing power and energy derived from photochemistry to fix carbon (original) (raw)
Related papers
On the origins of oxygenic photosynthesis and aerobic respiration in Cyanobacteria
Science (New York, N.Y.), 2017
The origin of oxygenic photosynthesis in Cyanobacteria led to the rise of oxygen on Earth ~2.3 billion years ago, profoundly altering the course of evolution by facilitating the development of aerobic respiration and complex multicellular life. Here we report the genomes of 41 uncultured organisms related to the photosynthetic Cyanobacteria (class Oxyphotobacteria), including members of the class Melainabacteria and a new class of Cyanobacteria (class Sericytochromatia) that is basal to the Melainabacteria and Oxyphotobacteria All members of the Melainabacteria and Sericytochromatia lack photosynthetic machinery, indicating that phototrophy was not an ancestral feature of the Cyanobacteria and that Oxyphotobacteria acquired the genes for photosynthesis relatively late in cyanobacterial evolution. We show that all three classes independently acquired aerobic respiratory complexes, supporting the hypothesis that aerobic respiration evolved after oxygenic photosynthesis.
Geological constraints on the origin of oxygenic photosynthesis
Photosynthesis Research, 2011
This article examines the geological evidence for the rise of atmospheric oxygen and the origin of oxygenic photosynthesis. The evidence for the rise of atmospheric oxygen places a minimum time constraint before which oxygenic photosynthesis must have developed, and was subsequently established as the primary control on the atmospheric oxygen level. The geological evidence places the global rise of atmospheric oxygen, termed the Great Oxidation Event (GOE), between ~2.45 and ~2.32 Ga, and it is captured within the Duitschland Formation, which shows a transition from mass-independent to mass-dependent sulfur isotope fractionation. The rise of atmospheric oxygen during this interval is closely associated with a number of environmental changes, such as glaciations and intense continental weathering, and led to dramatic changes in the oxidation state of the ocean and the seawater inventory of transition elements. There are other features of the geologic record predating the GOE by as much as 200–300 million years, perhaps extending as far back as the Mesoarchean–Neoarchean boundary at 2.8 Ga, that suggest the presence of low level, transient or local, oxygenation. If verified, these features would not only imply an earlier origin for oxygenic photosynthesis, but also require a mechanism to decouple oxygen production from oxidation of Earth’s surface environments. Most hypotheses for the GOE suggest that oxygen production by oxygenic photosynthesis is a precondition for the rise of oxygen, but that a synchronous change in atmospheric oxygen level is not required by the onset of this oxygen source. The potential lag-time in the response of Earth surface environments is related to the way that oxygen sinks, such as reduced Fe and sulfur compounds, respond to oxygen production. Changes in oxygen level imply an imbalance in the sources and sinks for oxygen. Changes in the cycling of oxygen have occurred at various times before and after the GOE, and do not appear to require corresponding changes in the intensity of oxygenic photosynthesis. The available geological constraints for these changes do not, however, disallow a direct role for this metabolism. The geological evidence for early oxygen and hypotheses for the controls on oxygen level are the basis for the interpretation of photosynthetic oxygen production as examined in this review.
The age of Rubisco: the evolution of oxygenic photosynthesis
Geobiology, 2007
The evolutionary history of oxygenesis is controversial. Form I of ribulose 1,5-bisphosphate carboxylase/ oxygenase (Rubisco) in oxygen-tolerant organisms both enables them to carry out oxygenic extraction of carbon from air and enables the competitive process of photorespiration. Carbon isotopic evidence is presented from 2.9 Ga stromatolites from Steep Rock, Ontario, Canada, ~2.9 Ga stromatolites from Mushandike, Zimbabwe, and 2.7 Ga stromatolites in the Belingwe belt, Zimbabwe. The data imply that in all three localities the reef-building autotrophs included organisms using Form I Rubisco. This inference, though not conclusive, is supported by other geochemical evidence that these stromatolites formed in oxic conditions. Collectively, the implication is that oxygenic photosynthesizers first appeared ~2.9 Ga ago, and were abundant 2.7-2.65 Ga ago.
The origin and evolution of oxygenic photosynthesis
Trends in Biochemical Sciences, 1998
The evolutionary developments that led to the ability of photosynthetic organisms to oxidize water to molecular oxygen are discussed. Two major changes from a more primitive non-oxygen-evolving reaction center are required: a charge-accumulating system and a reaction center pigment with a greater oxidizing potential. Intermediate stages are proposed in which hydrogen peroxide was oxidized by the reaction center, and an intermediate pigment, similar to chlorophyll d, was present.
The Origin and Evolution of Photosynthetic Oxygen Production
Advances in Photosynthesis and Respiration, 2005
Typesetter's note: This chapter should not have been sent to me as it does not appear to be a final version. The in-text references were incorrectly done and the end references were formatted incorrectly and using some bizarre scheme that necessitated redoing almost all of them. One entire section of the paper is missing (V. Concluding Remarks).
Evidence for oxygenic photosynthesis half a billion years before the Great Oxidation Event
Nature Geoscience, 2014
The early Earth was characterized by the absence of oxygen in the ocean-atmosphere system, in contrast to the well-oxygenated conditions that prevail today. Atmospheric concentrations first rose to appreciable levels during the Great Oxidation Event, roughly 2.5-2.3 Gyr ago. The evolution of oxygenic photosynthesis is generally accepted to have been the ultimate cause of this rise, but it has proved di cult to constrain the timing of this evolutionary innovation 1,2 . The oxidation of manganese in the water column requires substantial free oxygen concentrations, and thus any indication that Mn oxides were present in ancient environments would imply that oxygenic photosynthesis was ongoing. Mn oxides are not commonly preserved in ancient rocks, but there is a large fractionation of molybdenum isotopes associated with the sorption of Mo onto the Mn oxides that would be retained. Here we report Mo isotopes from rocks of the Sinqeni Formation, Pongola Supergroup, South Africa. These rocks formed no less than 2.95 Gyr ago 3 in a nearshore setting. The Mo isotopic signature is consistent with interaction with Mn oxides. We therefore infer that oxygen produced through oxygenic photosynthesis began to accumulate in shallow marine settings at least half a billion years before the accumulation of significant levels of atmospheric oxygen.
Anoxygenic photosynthesis modulated Proterozoic oxygen and sustained Earth's middle age
Proceedings of the National Academy of Sciences, 2009
Molecular oxygen (O2) began to accumulate in the atmosphere and surface ocean ca. 2,400 million years ago (Ma), but the persistent oxygenation of water masses throughout the oceans developed much later, perhaps beginning as recently as 580 -550 Ma. For much of the intervening interval, moderately oxic surface waters lay above an oxygen minimum zone (OMZ) that tended toward euxinia (anoxic and sulfidic). Here we illustrate how contributions to primary production by anoxygenic photoautotrophs (including physiologically versatile cyanobacteria) influenced biogeochemical cycling during Earth's middle age, helping to perpetuate our planet's intermediate redox state by tempering O 2 production. Specifically, the ability to generate organic matter (OM) using sulfide as an electron donor enabled a positive biogeochemical feedback that sustained euxinia in the OMZ. On a geologic time scale, pyrite precipitation and burial governed a second feedback that moderated sulfide availability and water column oxygenation. Thus, we argue that the proportional contribution of anoxygenic photosynthesis to overall primary production would have influenced oceanic redox and the Proterozoic O 2 budget. Later Neoproterozoic collapse of widespread euxinia and a concomitant return to ferruginous (anoxic and Fe 2؉ rich) subsurface waters set in motion Earth's transition from its prokaryote-dominated middle age, removing a physiological barrier to eukaryotic diversification (sulfide) and establishing, for the first time in Earth's history, complete dominance of oxygenic photosynthesis in the oceans. This paved the way for the further oxygenation of the oceans and atmosphere and, ultimately, the evolution of complex multicellular organisms.
2015
The evolution of oxygenic photosynthetic bacteria (OPB) is probably the most important biological event of Earth’s history since the emergence of life itself. The release of their by-product O2 in the environment, which was globally anoxic, fundamentally changed the face of the Earth and led to the development of complex life. However, the specific timing of this evolutionary step remains unclear. This study is based on the search for in situ chemical signatures of OPB at the microbial (μm) scale, within fossilized microbial photosynthetic mats in Archean and Paleoproterozoic sediments dated between 3.45 Ga and 1.88 Ga, i.e. spanning the anoxic Earth to the aftermath of the GOE. We used optical microscopy, Raman spectroscopy, SEM/EDS, EPMA, synchrotron radiation μ-XRF, and isotope analytical techniques. The μXRF results were improved by the use of a new sample preparation method and a new quantification method, both developed during this study.Results obtained by EPMA and μXRF show ...