Abstract

The purpose of this research paper was to review the different molecular biology techniques that are used in landfill investigations. The methods discussed include polymerase chain reaction (PCR), fluorescent in situ hybridization (FISH) and phospholipid fatty acid analysis (PLFA). Operation of landfills as bioreactors is now becoming a common practice, which involves the identification of different microbiological activities that facilitate the eventual breakdown of landfill wastes into useful and innocuous materials. In this review, the two important microbial activities that are discussed include methanotrophic process, carried out by methanotrophic bacteria, and methanogenic processes, carried out by methanogenic bacteria. Other bacteria encountered in landfills such as Nitrosospira and Nitrosomonas are also briefly discussed. As the name of these processes imply, methane oxidation and methane production by these microbial activities in landfills constitute another main focus of this paper. The application of these molecular biological techniques in real-time has also been demonstrated in studies involving the investigation of methanogenic diversity and activity in municipal solid waste landfill leachates and this is also discussed further. The results and conclusions of different research studies that focused on these techniques are hereby identified, discussed and summarized.

Key words: Bioreactors, polymerase chain reaction (PCR), fluorescent in situ hybridization (FISH), phospholipid fatty acid analysis (PLFA), methanogens, methanotrophs, landfilling.