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
Alkaline soil, sensible sensor
03.08.2017 | American Society of Agronomy
New 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences