Phylogenetics of Archaeal Lipids

Phylogenetics of Archaeal Lipids Outline • Phlogenetics of Archaea • Phlogenetics of archaeal lipids • Papers Phyla • Two? main phyla – Euryarchaeota • • • • Methanogens Extreme halophiles Extreme thermophiles Sulfate-reducing – Crenarchaeota • Extreme thermophiles – Korarchaeota? • Hyperthermophiles • indicated only by environmental DNA sequences – Nanoarchaeum? • N. equitans a fast evolving euryarchaeal lineage, not novel, early diverging archaeal phylum – Ancient archael group? • In deepest brances of Crenarchaea? Euryarchaea? Archaeal Lipids • Methanogens – Di- and tetra-ethers of glycerol and isoprenoid alcohols – Core mostly archaeol or caldarchaeol – Core sometimes sn-2- or sn-3-hydroxyarchaeol or macrocyclic archaeol – PMI • Halophiles – Similar to methanogens – Exclusively synthesize bacterioruberin • Marine Crenarchaea Archaeal Lipids Biological Origin Crocetane methanotrophs? PMI (2,6,10,15,19-pentamethylicosane) Squalane C31-C40 head-to-head isoprenoids methanogens, methanotrophs Depositional Environment methane seeps? hypersaline, anoxic hypersaline? Smit & Mushegian • “Lost” enzymes of MVA pathway must exist – Phosphomevalonate kinase (PMK) – Diphosphomevalonate decarboxylase – Isopentenyl diphosphate isomerase (IPPI) Boucher et al. • Isoprenoid biosynthesis of archaea evolved through a combination of processes – Co-option of ancestral enzymes – Modification of enzymatic specificity – Orthologous and non-orthologous gene displacement – Integration of components from eukaryotes and bacteria – Lateral gene transfer within and between archaeal orders Blumenberg et al. • Anaerobic oxidation of methane – Sulphate reducing bacteria – Anaerobic archaea • ANME-1 • ANME-2 Archaea involved in AOM • ANME-1 (Methanomicrobiales and Methanosarcinales of Euryarchaeota) – 13C depleted – Internally cyclized tetraether lipids – Nonisoprenoidal glycerol diethers • ANME-2 (Methanosarcinales of Euryarchaeota) – 13C depleted – sn-2-hydroxyarchaeol – Crocetane and crocetenes – Ester-linked diglycerides Image removed due to copyright considerations. Image removed due to copyright considerations. Schouten et al. • • • • • New glycerol dialkyl glycerol tetraethers HPLC/MS anaylysis of intact lipids Not just from hyperthermophiles Structures are diverse Organisms that make GDGTs can be a significant component of microbial communities a a methanogens a b a c c c c d d d Hyperthermophilic cultures Lowtemperature marine sediments d e psychophilic marine Extreme thermophilic Crenarchaeota can increase the number of pentacyclic rings with increasing T. Psychrophilic marine Crenarchaeota add a hexyl ring for low T I-VII identified as core ether lipids in hyperthermophilic archaea I is caldarchaeol II-VII present in hyperthermophilic and nonthermophilic archaea VIII predominantly synthesized by marine nonthermophilic Crenarchaeota X-XIV terrestrial Koga & Morii • Archaeal lipids – Core • Archaeol • Caldarchaeol • New – Phosphodiester bonded polar head group or glycoside Classes • Cultivated Euryarchaeota fall into eight classes – – – – – – – – Archaeoglobi Halobacteria Thermococci Thermoplasmata Methanopyri Methanococci Methanobacteria Methanomicrobia • Cultivated Crens fall into 1 class with four orders – Thermoprotei • • • • Thermoproteales Caldisphaerales Desulfurococcales Sulfolobales Key Genera Phylum Euryarchaeota • • • • • • • • • • • • • • Halobacterium Haloferax Natronobacterium Methanobacterium Methanocaldococcus Methanosarcina Thermoplasma Ferroplasma Picrophilus Thermococcus Pyrococcus Methanopyrus Archaeoglobus Ferroglobus Extreme halophiles Methanogens Thermophilic and extremely acidophilic Hypothermophiles Key Genera Phylum Crenarchaeota • • • • • • • Sulfolobus Hyperthermophiles from terrestrial volcanic habitats Acidianus Thermoproteus Pyrodictium Pyrolobus Hyperthermophiles from submarine volcanic habitats Ignicoccus Staphlothermus