Monthly Archives: August 2019

“There are microbes living in deep ocean sediments eating carbon, like proteins and carbohydrates, that is hundreds of years old,” said Andrew Steen, lead author of the study and assistant professor of environmental geology at UT. “However, we don’t know much about how those microbes eat that old, poor-quality food.”

Understanding how these microorganisms function on low-quality foods 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.

“It could also aid in preserving underground microbes that play a role in carbon sequestration, a key process in the fight against climate change,” said Steen.

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.

“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 Steen. “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.”

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.

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.

“Our study shows that, in some sense, subsurface microbes are happy to be where they are — or at least they’re well adapted to a terrible environment,” said Steen.

Cattle, like humans, harbour a wide range of bacteria in their noses, microbes which are normally present and probably necessary for health like those that live in the gut. However, some species of these bacteria do cause serious illness at times, particularly when infection becomes established in the lower respiratory tract within the lungs.

In an open access paper published in Scientific Reports today [Friday 16 August], the researchers investigated the patterns of acquiring and clearing these microbes in healthy young cattle, which have not previously been studied in detail.

The research team took nasal swabs at intervals during the first year of life, to detect their presence and measure their abundance using a DNA-detection technique called quantitative polymerase chain reaction (qPCR) that targeted genes found in three bacterial species well-known for their ability to cause respiratory disease in cattle: Histophilus somni, Mannheimia haemolytica and Pasteurella multocida.