Learning how these microorganisms function on old, poor-quality food at a very slow pace could have future uses in biomedical applications such as a technology that could slow down cell metabolism in human organs so they can survive longer during a transplant process.
To better understand how these microorganisms access this food, researchers tested different types of peptidases—digestive enzymes that work to degrade proteins—in sediment cores from the White Oak River estuary in North Carolina.
The data collected by the researchers represented about 275 years of sediment deposition from the White Oak River estuary. Using DNA analysis of the microbes in these sediments, and by measuring peptidases, researchers evaluated how these microorganisms metabolize with little access to fresh organic matter.
Credit: University of Tennessee, Knoxville
Organic carbon buried in aquatic sediments is a long-term sink for atmospheric carbon dioxide, and about 40 percent of organic carbon burial occurs in estuaries and deltaic systems. Steen’s study gives insight into how these subsurface microbial communities begin the process of degrading organic carbon in such environments.
“These microbes live incredibly slow lives, with cells multiplying somewhere between every 10 years and every 10,000 years, but we aren’t sure how,” said Andrew Steen, lead author of the study and assistant professor of environmental geology at the University of Tennessee, Knoxville. “Our work shows that those microbes are living the same way any other microbe does, just way more slowly and with some improved ability to eat the low-quality food in their environment.”