The biosynthesis of tetrahymanol in bacteria

In our latest journal club, we discussed the biosynthesis of tetrahymanol (Fig. 1) in Bacteria 1, which is of importance in organic geochemistry as it is the precursor of the biomarker gammacerane. Gammacerane is a pentacyclic triterpenoid (Fig. 1) and was documented for the first time in the Green River Shale in 1966 2, while … More The biosynthesis of tetrahymanol in bacteria

2-methyl hopanoids in Bacteria: what do they do?

In our last “Papers & Cake” in 2015, we discussed a paper by Wu et al. (2015) which explores the occurrence of 2-methyl hopanoids in the cell membrane of bacterium Rhodopseudomonas palustris TIE-1. Background: In Bacteria, hopanoids help to rigidify and regulate the cell membrane (Figure 1). These compounds typically consist of a C30 ring system and an … More 2-methyl hopanoids in Bacteria: what do they do?

Alkenones as a proxy for lake temperature?

In this edition of Papers ‘n’ Cake, we discuss an article by Jaime Toney and colleagues (Toney et al., 2010) that explores the occurrence of long-chain alkenones in lacustrine settings and their application as a paleotemperature proxy. Alkenones in the marine realm: During the late 1970s and early 1980s, researchers from Delft University of Technology (Boon et al, 1978; De … More Alkenones as a proxy for lake temperature?

What’s the dirt on lipid biomarkers and soil pH?

Previous studies have shown that bacterial membrane lipids are sensitive to changes in environmental parameters such as soil pH (e.g. Weijers et al,. 2007) and have enabled the development of the CBT index, a soil pH proxy based upon the number of cyclopentane rings within these lipids. Although the CBT proxy has evolved in recent years (see De Jonge et al., … More What’s the dirt on lipid biomarkers and soil pH?

The leaf wax composition and stable carbon isotope value of conifers: should we care?

The stable carbon isotopic composition (δ13C) of organic matter provides key information about fundamental metabolic pathways used by the organism and the environmental conditions during formation. … More The leaf wax composition and stable carbon isotope value of conifers: should we care?

Anaerobic methane oxidation in freshwater wetlands?

Methane emitted from wetlands plays a major role in the global climate – it is a powerful greenhouse gas, and it is produced by microbes. The methane cycle in wetlands is a complex process, as the methane is produced deeper down, in the anoxic part of the wetland sediment, and then rises up through its … More Anaerobic methane oxidation in freshwater wetlands?