User:Willleon2020/sandbox

Modern (Austin)

Marine: Anoxygenic photosynthesis by marine algae (cyanobacteria/dinoflagellates) and bacteria is potentially of great ecological importance to the world's oceans where they are abundant [1AW,2AW]. anoxygenic photosynthetic bacteria facilitate the process in photic, anoxic marine environments where hydrogen sulfide is available and light intensity is low [3aw]. Optimal habitats include stratified seas [xxxx], sediment layers[4aw], salt marshes [5aw], intertidal microbial mats[4aw ], anoxic microzones associated with particulate matter[2aw], and even within the guts of zooplankton (though not their fecal pellets) [ 3aw].

Some aerobic photoheterotrophic alpha-bacteria are also capable of anoxygenic photosynthesis and account for as much as 10% of the bacterial biomass off the coast of Washington and Oregon [kolber 2001]. Their ability for anoxygenic photosynthesis may be more important in oligotrophic waters where photoheterotrophic bacteria are more likely to be limited by the availability of reduced carbon[2aw].

Intertidal:

Anoxygenic photosynthesis has the potential to be substantial in intertidal mudflats and salt marsh systems where ideal conditions for anoxygenic photosynthesis exist, with great S and Fe redox gradients in near surface sediments and there is ample light availability. [7aw]

Freshwater:

Anoxygenic photosynthetic bacteria typically stratify in anoxic water, such as shallow ponds of stagnant water[5aw], hotsprings[5aw], or stratified sulfuric lakes[6aw], forming thick brown, green, or pink aggregations at the mixing layer, where very sharp gradients in temperature, light, and chemical concentrations (e.g. Oxygen and sulfide) favor their growth [6aw]. The mixing layer depth within lakes may vary seasonally and cause changes in anaerobic primary production due to the intensity of ambient light. Optimal growth conditions may be self-limiting as a reduction of light intensity from self-shading can limit growth even when nutrients are non-limiting.[6aw]

Terrestrial:

Aerobic anoxygenic phototrophic bacteria have been reported to exist in biological soils, comprising 0.1–5.9% of the cultivable bacterial community in moss, lichen and cyanobacteria‐dominated crust from sand dunes and sandy soils, and could accelerate organic carbon cycling in nutrient-poor arid soils.Their effects will be especially important as global climate change enhances soil erosion and consequent nutrient loss. [9aw][11aw]

SOURCES [1aw] llgaier, M., Uphoff, H., Felske, A., & Wagner-Dobler, I. (2003). Aerobic Anoxygenic Photosynthesis in Roseobacter Clade Bacteria from Diverse Marine Habitats. Applied and Environmental Microbiology, 69(9), 5051–5059. doi:10.1128/aem.69.9.5051-5059.2003

[2] Goericke, R. 2002. Bacteriochlorophyll a in the ocean: is anoxygenic bacterial photosynthesis important? Limnol. Oceanogr. 47:290–295.

[3aw] PROCTOR, L. M. 1997. Nitrogen-ﬁxing, photosynthetic, anaerobicbacteria associated with pelagic copepods. Aquat. Microb.Ecol. 12: 105–113.

[4aw] Hunter, C.N., Daldal, F., Thurnauer, M.C., Beatty, J.T. "The Purple Phototropic Bacteria", Springer-Dordrecht, 2008.

[5aw] Paterek JR, Paynter JB (1988) Populations of anaerobic phototrophic bacteria in a Spartina altern~flora salt marsh. Appl Environ M~crobiol5 4:1360-1364 Pfennig N (1978) General physiology

[6aw]Guerrero R, Montesinos E, Pedros-Aho C, Esteve I, Mas J, Gemerden HV. Hofman PAG, Bakker JF (1985) Phototrophic bacteria in two Spanish lakes. I. Vertical distribution and limiting factors. Limnol Oceanogr 30: 919-930

[7aw]Wang, S. R., Di Iorio, D., Cai, W.-J., & Hopkinson, C. S. (2017). Inorganic carbon and oxygen dynamics in a marsh-dominated estuary. Limnology and Oceanography, 63(1), 47–71. https://doi.org/10.1002/lno.10614

[8aw] redundant

[9aw] Csotonyi J. T., Swiderski J., Stackebrandt E., Yurkov V. (2010). A new environment for aerobic anoxygenic phototrophic bacteria: biological soil crusts. Environ. Microbiol. Rep. 2 651–656. 10.1111/j.1758-2229.2010.00151.x [PubMed] [CrossRef] [Google Scholar]

[10aw] Lehours, A. C., Enault, F., Boeuf, D., and Jeanthon, C. (2018). Biogeographic patterns of aerobic anoxygenic phototrophic bacteria reveal an ecological consistency of phylogenetic clades in different oceanic biomes. Sci. Rep. 8:4105. doi: 10.1038/s41598-018-22413-7

[11aw] Wei H, Peng C, Yang B, Song H, Li Q, Jiang L, Wei G, Wang K, Wang H, Liu S, Liu X, Chen D, Li Y and Wang M (2018) Contrasting Soil Bacterial Community, Diversity, and Function in Two Forests in China. Front. Microbiol. 9:1693. doi: 10.3389/fmicb.2018.01693