Premium
Vertical distribution of structure and function of the methanogenic archaeal community in Lake Dagow sediment
Author(s) -
Chan On Chim,
Claus Peter,
Casper Peter,
Ulrich Andreas,
Lueders Tillmann,
Conrad Ralf
Publication year - 2005
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2005.00790.x
Subject(s) - biology , sediment , distribution (mathematics) , archaea , ecology , function (biology) , community structure , evolutionary biology , bacteria , paleontology , mathematical analysis , mathematics
Summary Detailed studies on the relation of structure and function of microbial communities in a sediment depth profile scarcely exist. We determined as functional aspect the vertical distribution of the acetotrophic and hydrogenotrophic CH 4 production activity by measuring production rates and stable 13 C/ 12 C‐isotopic signatures of CH 4 in the profundal sediment of Lake Dagow. The structural aspect was determined by the composition of the methanogenic community by quantifying the abundance of different archaeal groups using ‘real‐time’ polymerase chain reaction and analysis of terminal restriction fragment length polymorphism (T‐RFLP). Methane production rates in the surface sediment (0–3 cm depth) were higher in August than in May, but strongly decreased with depth (down to 20 cm). The δ 13 C of the produced CH 4 and CO 2 indicated an increase in isotopic fractionation with sediment depth. The relative contribution of hydrogenotrophic to total methanogenesis, which was calculated from the isotopic signatures, increased with depth from about 22% to 38%. Total numbers of microorganisms were higher in August than in May, but strongly decreased with depth. The increase of microorganisms from May to August mainly resulted from Bacteria . The Archaea , on the other hand, exhibited a rather constant abundance, but also decreased with depth from about 1 × 10 8 copies of the archaeal 16S rRNA gene per gram of dry sediment at the surface to 4 × 10 7 copies per gram at 15–20 cm depth. T‐RFLP analysis combined with phylogenetic analysis of cloned sequences of the archaeal 16S rRNA genes showed that the methanogenic community consisted mainly of Methanomicrobiales and Methanosaetaceae . The relative abundance of Methanosaetaceae decreased with depth, whereas that of Methanomicrobiales slightly increased. Hence, the vertical distribution of the functional characteristics (CH 4 production from acetate versus H 2 /CO 2 ) was reflected in the structure of the community consisting of acetotrophic ( Methanosaetaceae ) versus hydrogenotrophic ( Methanomicrobiales ) phenotypes.