0000000000595872
AUTHOR
Daniela Polag
Methane oxidation in industrial biogas plants-Insights in a novel methanotrophic environment evidenced by pmoA gene analyses and stable isotope labelling studies.
Abstract A broad methanotrophic community consisting of 16 different operational taxonomic units (OTUs) was detected by particulate methane monooxygenase A (pmoA) gene analyses of reactor sludge samples obtained from an industrial biogas plant. Using a cloning-sequencing approach, 75% of the OTUs were affiliated to the group of type I methanotrophs (γ-Proteobacteria) and 25% to type II methanotrophs (α-Proteobacteria) with a distinct predominance of the genus Methylobacter. By database matching, half of the total OTUs may constitute entirely novel species. For evaluation of process conditions that support growth of methanotrophic bacteria, qPCR analyses of pmoA gene copy numbers were perfor…
Stable isotope fractionation in speleothems: Laboratory experiments
Abstract In recent years, stalagmites have become important archives for paleoclimate. Several studies applying carbon and oxygen isotopes of stalagmites show a simultaneous increase of δ 13 C and δ 18 O along individual growth layers, which is interpreted as being indicative of isotope fractionation under disequilibrium conditions. In order to obtain robust paleoclimatic information from calcite precipitated under these non-equilibrium conditions it is important to improve the quantitative understanding of the corresponding isotope fractionation processes. Here we present laboratory experiments simulating calcite precipitation under cave-analogue conditions. The major focus was the investi…