Bacteria from 55-Yr.-Old Coal Fire Studied
Taylor Dunivin, a doctoral student in the Department of Microbiology and Molecular Genetics, studies bacteria living in the surface soils of Centralia, Penn., the site of an underground coal mine fire that ignited back in 1962. Her goal: to measure both antibiotic resistance genes and arsenic resistance genes in the different soil microbial communities to see how the bacteria respond or change both in community membership and in functional profile.
“Centralia is a great place to study whether antibiotic resistance increases in areas that have experienced a fire and whether the number of resistance genes changes once the environment recovers,” says Dunivin. “Arsenic is naturally found in coal and likely to increase abundance in sites in Centralia where steam from coal burning actively passes through the soil.
Dunivin notes that antibiotic resistance is a pressing public health concern. “Information on how anthropogenic fire, such as pollution and temperature, increases the spread of antibiotic resistance in the environment will help us better reduce and/or control it,” she says. “The use of antibiotics saves lives daily; arsenic exposure at low doses negatively impacts almost every organ system and at high doses can result in death.”
She has already had some successes in her quest, describing the times when the research showed progress: “The day the bacteria from Centralia soils grew on agar plates with high concentrations of arsenic, the day we first assembled complete arsenic resistance genes from DNA sequences from Centralia soils, and the day we got back our arsenic results and saw that arsenic concentrations are increasing in sites that are currently impacted by the fire.”
But there have been challenges. “We hoped to find some bacteria that oxidized arsenate in Centralia, but we could only grow strains that did the opposite. Additionally, working with these huge datasets of microbial community DNA has many challenges. We can only accurately sequence a small piece of DNA at once, so our sequencing first requires us to cut the DNA into smaller pieces. To analyze it we need to try and put them all back together…it’s a little like putting a puzzle together without a reference picture or even all of the pieces.”
- Excerpted from an article by Kristin Lauzon and Taylor Dunivin, Institute for Cyber-Enabled Research
Photo by: Xiaoxing (Adele) Han