Characterization of Methanotroph Diversity and Population Response in a Freshwater Lake Upon Exposure to Benzene

EPA Grant Number: U916172
Title: Characterization of Methanotroph Diversity and Population Response in a Freshwater Lake Upon Exposure to Benzene
Investigators: Fisher, Meredith C.
Institution: Harvard University
EPA Project Officer: Zambrana, Jose
Project Period: January 1, 2003 through January 1, 2006
Project Amount: $87,886
RFA: STAR Graduate Fellowships (2003) Recipients Lists
Research Category: Fellowship - Microbiology , Academic Fellowships , Biology/Life Sciences


The objective of this research project is to assess methanotroph diversity and functioning within Mishwam Lake, a freshwater, stratified lake in northern Massachusetts, including their potential role in the degradation of benzene and benzene derivatives.


Methanotroph bacteria are environmentally relevant because of their role in methane cycling, a greenhouse gas linked to global warming, and bioremediation of organic pollutants. These functions are facilitated by the methanotroph-specific enzyme methane mono-oxygenase (MMO). Because of its indiscriminant functioning, MMO oxidizes methane as well as other organic compounds including aromatics and halogenated molecules. As a result, methanotrophs have received much attention for their role in bioremediation at polluted sites. One such site where methanotrophs might potentially be acting in a bioremediative capacity is Mishwam Lake, which suffers from a high degree of contamination by benzene and benzene derivatives. Environmental chemistry studies have found high rates of benzene loss at the oxic/anoxic interface of the lake as well as high concentrations of methane and oxygen. This research project will be accomplished by an indepth analysis of the methanotroph communities in the lake using molecular biology techniques as well as cultured isolates to perform in vitro degradation studies. The introduction of a set of methanotroph-specific probes and primers allows for indepth field studies of methanotroph diversity and relative abundance. This research project will increase our knowledge of both the significance and function of methanotroph communities in disturbed environments and allow for an assessment of their bioremediation potential at sites suffering from high levels of organic pollution.

Supplemental Keywords:

fellowship, bioremediation, freshwater, benzene, contamination, organic pollution, methanotroph bacteria, methane mono-oxygenase, MMO, methane cycling.

Progress and Final Reports:

  • 2003
  • 2004
  • Final