A long history of mining in the Pacific Northwest has led to high levels of heavy metals in the sediments of some area lakes and rivers. However, microorganisms that live in these sediments, such as those found in the metal-contaminated Lake Coeur d’Alene, are capable of detoxifying their environment.

Brent Peyton and Rajesh Sani, researchers in the Center for Multiphase Environmental Research, at Washington State University, have received a four-year, $1.2 million grant from the National Science Foundation’s Biocomplexity Program to characterize indigenous microorganisms in the sediments of Lake Coeur d’Alene and to analyze their role in the transport of metals through the environment.

The project focuses on characterizing microbial communities and developing a quantitative model to describe microbially driven reactions of the toxic metals lead, copper, and zinc. Peyton and Sani will use DNA extraction to characterize the microbial diversity of sediments collected from Lake Coeur d’Alene. In the laboratory, they will then measure changes in the microbial populations as they are exposed to higher metal stress.

Although there are typically millions of microorganisms and hundreds to thousands of different bacterial species in any given teaspoon of soil, the researchers will focus on a few dominant representatives. Peyton and Sani theorize that unique, metal-tolerant microorganisms may be dominant in the sediments, and that these microorganisms may influence the movement of the contaminants through the environment.

In collaboration with Timothy Ginn at the University of California-Davis and Nicholas Spycher at Lawrence Berkeley Labs, the researchers will also develop computer simulations to help explain the interaction of the bacteria with the metals in the Coeur d’Alene River Basin and to understand the conditions that would make for optimal clean-up.