||Jorg Overmann and Ferran Garcia-Pichel, The Phototrophic Way of Life, Prokaryotes (2006) 2:32–85 chapter 1.3, edited by Stanley Falkow, Eugene Rosenberg, Karl-Heinz Schleifer, Erko Stackebrandt DOI: 10.1007/0-387-30742-7_3 p.33 left column top paragraph
||Overmann, J. 1997. Mahoney Lake: A case study of the ecological significance of phototrophic sulfur bacteria. In: Jones JG (Eds.) Advances in Microbial Ecology Vol. 15. Plenum Press. New York, 251–288.
||P.32 right column bottom paragraph: "Today, the significance of anoxygenic photosynthesis for global carbon fixation is limited for two reasons. On the one hand, phototrophic sulfur bacteria (the dominant anoxygenic phototrophs in natural ecosystems) form dense accumulations only in certain lacustrine environments and in intertidal sandflats. The fraction of lakes and intertidal salt marshes that harbor anoxygenic phototrophic bacteria is unknown, but these ecosystems altogether contribute only 4% to global primary production (BNID 113691). In those lakes harboring phototrophic sulfur bacteria, an average of 28.7% of the primary production is anoxygenic (BNID 113692). Consequently, the amount of CO2 fixed by anoxygenic photosynthesis must contribute much less than 1% to global primary production."