Escherichia coli is a commonly used indicator organism for detecting the presence of fecal contamination in drinking water supplies.
The importance of E. coli as an indicator organism has led to several studies looking at the transport behavior of this important microorganism in groundwater environments. Commonly only a single strain of E. coli is used in these studies, yet research has shown that a significant amount of genetic variability exists among strains of E. coli isolated from different host species and even from the same host species. If these genetic differences result in differences in cell properties that affect transport, different strains of E. coli may exhibit different rates of transport in the environment.
A scientist at the USDA-ARS Animal Waste Management Research Unit in Bowling Green, Kentucky, in collaboration with researchers at the University of California at Riverside, compared cell properties and transport behavior of 12 different E. coli isolates obtained from six different fecal sources. Results from this study were published in the March-April issue of Journal of Environmental Quality.
For all 12 E. coli isolates, the following cell properties known to affect bacterial transport in the environment were measured: surface charge, hydrophobicity, cell size and shape, and the composition of the extracellular polymeric substance. Transport behavior of the E. coli isolates was assessed by measuring the amount of cells that were able to pass through columns packed with clean aquifer sands. The measured breakthrough concentrations of the bacteria were then modeled so that transport parameters for each E. coli isolate could be estimated. Correlations between measured cell properties and transport parameters were investigated.
Although each E. coli isolate was subjected to the exact same storage and growth conditions, the researchers observed a large range in measured cell properties, bacterial recovery, and fitted transport parameters for the different isolates. For example, cell hydrophobicity and surface charge were observed to vary by over an order of magnitude for the 12 different E. coli isolates. The total amount of bacteria passing through the sand columns ranged from less than 2% for one of the horse isolates to 95% for one of the beef cattle isolates and the fitted model parameters ranged by a factor of 50 for the different E. coli isolates. The only cell property observed to be statistically correlated with transport behavior of the E. coli isolates was cell width.
Carl Bolster, the lead scientist on the study, stated “This diversity in transport behavior must be taken into account when making assessments of the suitability of using E. coli as an indicator organism for specific pathogenic microorganisms in groundwater. In addition, our results suggest that the modeling of E. coli in the environment will likely require a distribution of bacterial attachment rates, even when modeling E. coli movement from a single fecal source.”
Research is ongoing at USDA-ARS and UC Riverside to investigate the range in diversity in cell properties and transport behavior of E. coli under a variety of different experimental conditions; these include different growth conditions and types of sediment. Further research is needed to identify cell properties controlling E. coli transport in the environment.
The Journal of Environmental Quality, http://jeq.scijournals.org is a peer-reviewed, international journal of environmental quality in natural and agricultural ecosystems published six times a year by the American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and the Soil Science Society of America (SSSA). The Journal of Environmental Quality covers various aspects of anthropogenic impacts on the environment, including terrestrial, atmospheric, and aquatic systems.
The Crop Science Society of America (CSSA), founded in 1955, is an international scientific society comprised of 6,000+ members with its headquarters in Madison, WI. Members advance the discipline of crop science by acquiring and disseminating information about crop breeding and genetics; crop physiology; crop ecology, management, and quality; seed physiology, production, and technology; turfgrass science; forage and grazinglands; genomics, molecular genetics, and biotechnology; and biomedical and enhanced plants.
CSSA fosters the transfer of knowledge through an array of programs and services, including publications, meetings, career services, and science policy initiatives.
Sara Uttech | EurekAlert!
Further reports about: > CSSA > E. coli > E. coli strains > Escherichia coli > Science TV > USDA-ARS > cell hydrophobicity > cell size and shape > crop > crop ecology > drinking water supplies > environmental risk > extracellular polymeric substance > fecal contamination > genetic variability > hydrophobicity > microorganism in groundwater environments > specific pathogenic microorganisms > surface charge
Forest Management Yields Higher Productivity through Biodiversity
14.10.2016 | Technische Universität München
Farming with forests
23.09.2016 | University of Illinois College of Agricultural, Consumer and Environmental Sciences (ACES)
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences