APR 21, 2020 3:50 PM PDT

A 2020 Census for Microbes in Florida Springs

WRITTEN BY: Carmen Leitch

Water sources are vital to communities and wildlife alike, and it's important to monitor their health. The Floridan Aquifer, for example, supplies drinking water to around ten million individuals, provides a home for manatees in chilly months, and a recreational area for people. It's also under threat from rising seas, agricultural runoff, and stresses caused by development. Researchers have now assessed the bacterial, viral, and archaeal communities that reside in the aquifer, the first study of its kind. The findings have been reported in mBio.

"It really shocked us that this hasn't been done before," said senior study author Dr. Mya Breitbart, a professor at the USF College of Marine Science.

In this study, from May to June 2017 the researchers took samples from five springs in northern Florida that serve as a mirror of the aquifer, Breitbart said. Together, the springs discharge more than 246 million liters of water a day. With microscopy and genetic tools, the scientists identified the microbes in the aquifer, and checked health indicators like nutrient and dissolved oxygen levels.

The researchers found much lower levels of bacteria than what they expected - on the order of 100 to 1000 times less than what's been found in other surveys of groundwater. What they found was similar to what's seen in other marine environments, said Malki. They did identify 60 new viral genomes, some of which may be able to infect bacteria and other viruses that could potentially infect eukaryotic cells.

They also found unique groups in each spring. Malki theorized that a spring's microbial population is affected by local land usage, though relatively high levels of Proteobacteria, Cyanobacteria, and Bacteroidetes were found in all the springs.

"Our original hypothesis going in was that the communities living in each spring would look similar because the springs are fed by the same aquifer," said Kema Malki, a USF Ph.D. student, "but they don't look similar at all."

Viral genomes can be made of different kinds of genetic material, including RNA, single- or double-stranded DNA (ssDNA or dsDNA). Most viruses in the Ichetucknee Spring were ssDNA viruses. Usually, large dsDNA viruses dominate marine ecosystems.

"We know so little about these single-stranded DNA viruses," Breitbart said, "and we have a lot more to learn about the roles they play in aquatic ecosystems." The researchers applied a technique that can amplify both single- and double-stranded DNA. Many typical methods only detect dsDNA viruses.

They also learned about the state of the aquifer.

"The concentrations of phosphate and nitrate we found in certain springs were very high compared to the concentrations reported in other groundwater environments," Malki added. Extremely high nitrate levels were found in Jackson Spring, while Volusia Spring had the highest phosphate concentration. "We knew there was a growing water quality issue in the springs but didn't expect the numbers to be that high," Malki said.

The study suggested that land use may be having a dramatic impact on these marine microbial populations.

Forest and agricultural land surrounds the water feeding Jackson Springs, and the most urbanized environment was found around Volusia Spring. At Volusia, bacterial and viral levels were ten times higher than at other sites.

"We'd need to drill down further to really know what's going on here," Malki said, "but we can confidently say that each spring site is different even though they are all fed by the same aquifer."

A variety of follow-up studies are now planned.

Sources: Phys.org via University of South Florida, mBio

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
FEB 27, 2020
Cell & Molecular Biology
FEB 27, 2020
Caloric Restriction Changes Gene Expression, Reduces Inflammation
New research has added to the evidence that suggests that dietary restriction has health benefits.
MAR 04, 2020
Cell & Molecular Biology
MAR 04, 2020
CRISPR Used Inside of a Patient For the First Time
In a first, scientists have used the CRISPR gene-editing tool inside of a person's body to treat a serious eye disorder.
APR 09, 2020
Cell & Molecular Biology
APR 09, 2020
A Model of Spinal Development Provides Insight Into Disease
The spinal column develops from a row of structures called somites, which bud off sequentially in a process called somit ...
APR 19, 2020
Genetics & Genomics
APR 19, 2020
Two New Viruses IDed in Brazilian Patient Samples
After an assessment of blood samples collected in Brazil between 2013 and 2016, scientists have found two new species of ...
APR 20, 2020
Genetics & Genomics
APR 20, 2020
Advances in Gene Therapy for Neurons
New research may aid in the development of gene therapies for diseases like Alzheimer's and Parkinson's.
MAY 10, 2020
Cell & Molecular Biology
MAY 10, 2020
RNA Structure Informs RNA Function
Proteins carry out many of an organism's critical functions, and they are coded for by genes. To make a protein from ...
Loading Comments...