Thu, 24 Jul 2008 02:33:14 BST CiteULike: de vrich Sessions http://www.citeulike.org/user/vrich/author/Sessions CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/vrich/article/2785943 <i>Proceedings of the National Academy of Sciences, Vol. 104, No. 38. (18 September 2007), pp. 15099-15104.</i><br /><br />Sedimentary 2-methyhopanes have been used as biomarker proxies for cyanobacteria, the only known bacterial clade capable of oxygenic photosynthesis and the only group of organisms found thus far to produce abundant 2-methylbacteriohopanepolyols (2-MeBHPs). Here, we report the identification of significant quantities of 2-MeBHP in two strains of the anoxygenic phototroph Rhodopseudomonas palustris. Biosynthesis of 2-MeBHP can occur in the absence of O2, deriving the C-2 methyl group from methionine. The relative abundance of 2-MeBHP varies considerably with culture conditions, ranging from 13.3% of total bacteriohopanepolyol (BHP) to trace levels of methylation. Analysis of intact BHPs reveals the presence of methylated bacteriohopane-32,33,34,35-tetrol but no detectable methylation of 35-aminobacteriohopane-32,33,34-triol. Our results demonstrate that an anoxygenic photoautotroph is capable of generating 2-MeBHPs and show that the potential origins of sedimentary 2-methylhopanoids are more diverse than previously thought. 10.1073/pnas.0704912104 Biosynthesis of 2-methylbacteriohopanepolyols by an anoxygenic phototroph Sky Rashby Alex Sessions Roger Summons Dianne Newman doi:10.1073/pnas.0704912104 Proceedings of the National Academy of Sciences, Vol. 104, No. 38. (18 September 2007), pp. 15099-15104. 2008-05-11T23:09:04-00:00 2007 Proceedings of the National Academy of Sciences 104 38 15099 15104 lipids http://www.citeulike.org/user/vrich/article/1132902 <i>Geobiology, Vol. 5, No. 1. (March 2007), pp. 85-95.</i> Carbon-isotopic analysis of microbial cells sorted by flow cytometry KM Eek AL Sessions DP Lies doi:10.1111/j.1472-4669.2006.00094.x Geobiology, Vol. 5, No. 1. (March 2007), pp. 85-95. 2007-03-01T02:44:20-00:00 2007 Geobiology 1472-4677 5 1 85 95 Blackwell Publishing fcm