Characterization of methanogenic Archaea in the leachate of a closed municipal solid waste landfill

Abstract

Cultivation-independent molecular approaches were used to investigate the phylogenetic composition of Archaea and the relative abundance of phylogenetically defined groups of methanogens in the leachate of a closed municipal solid waste landfill. Cloning and phylogenetic analysis of archaeal 16S rRNA gene sequences (16S rDNA) revealed that the landfill leachate harbored a diverse Archaea community, with sequence types distributed within the two archaeal kingdoms of the Euryarchaeota and the Crenarchaeota. Of the 80 clones examined, 51 were phylogenetically associated with well-defined methanogen lineages covering two major methanogenic phenotypes; 20 were related to Thermoplasma and were grouped with some novel archaeal rRNA gene sequences recently recovered from various anaerobic habitats; finally, five belonged to Crenarchaeota and were not closely related to any hitherto cultivated species. Most of the methanogen-like clones were affiliated with the hydrogenotrophic Methanomicrobiales and the methylotrophic and acetoclastic Methanosarcinales. Quantitative oligonucleotide hybridization experiments showed that methanogens in the leachate accounted for only a very small fraction of the total community (approximately 2%) and that Methanomicrobiales and Methanosarcinales constituted the majority of the total methanogenic population.

Bioaugmentation for improved recovery of anaerobic digesters after toxicant exposure

“…In addition, 41% of the clones could only be placed in the phylum Crenarchaeota, class Thermoprotei. These sequences were most similar to an uncultured clone sequence from leachate in a municipal solid waste landfill (98% similarity) (Huang et al, 2003). The unknown Archaean sequences could not be further classified taxonomically and it is difficult to suggest what role they play in the microbial community.…”

“…2). These sequences were most similar to an uncultured clone sequence from leachate in a municipal solid waste landfill (98% similarity) (Huang et al, 2003).…”

Archaea of the Miscellaneous Crenarchaeotal Group are abundant, diverse and widespread in marine sediments

“…MCG are present in terrestrial hot springs , deep oceanic subsurface sediments (Parkes et al, 2005), deep terrestrial subsurface (Inagaki et al, 2003), continental shelf sediments (Vetriani et al, 1998), ancient marine sapropels (Coolen et al, 2002), petroleum-contaminated soil (Kasai et al, 2005), termite guts (Friedrich et al, 2001), mud volcanoes (Heijs et al, 2007), methane hydrate-containing marine sediments (Inagaki et al, 2006), landfill leachate (Huang et al, 2003), anaerobic wastewater reactors (Collins et al, 2005), sulfidic springs (Elshahed et al, 2003), brackish lakes (Hershberger et al, 1996) and coastal salt marshes (Castro et al, 2004). Only 28 out of 4720 MCG sequences were retrieved from potentially oxic habitats (for example, database releases EU370096 and FJ560325).…”

Effect of Biowaste Sludge Maturation on the Diversity of Thermophilic Bacteria and Archaea in an Anaerobic Reactor

“…Its frequency increased from 90.8% in F-A to 100% in M-A. In F-A, other clones appeared that were most closely related to clone GZK24, detected in the leachate of a municipal solid waste landfill (14), or to the hydrogenotroph Methanothermobacter thermautotrophicus (11). Therefore, there was a decrease in the archaeal clonal diversity following maturation of the biowastes, with a total disappearance of methanogens other than Methanoculleus sp.…”