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Environmental Microbiology and Microbial Ecology

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2001

Articles 1 - 6 of 6

Full-Text Articles in Entire DC Network

Aerobic Biodegradation Of Methyl Tert-Butyl Ether By Aquifer Bacteria From Leaking Underground Storage Tank Sites, S. R. Kane, H. R. Beller, T. C. Legler, C. J. Koester, Holly C. Pinkart, R. U. Halden, A. M. Happel Dec 2001

Aerobic Biodegradation Of Methyl Tert-Butyl Ether By Aquifer Bacteria From Leaking Underground Storage Tank Sites, S. R. Kane, H. R. Beller, T. C. Legler, C. J. Koester, Holly C. Pinkart, R. U. Halden, A. M. Happel

All Faculty Scholarship for the College of the Sciences

The potential for aerobic methyl tert-butyl ether (MTBE) degradation was investigated with microcosms containing aquifer sediment and groundwater from four MTBE-contaminated sites characterized by oxygen-limited in situ conditions. MTBE depletion was observed for sediments from two sites (e.g., 4.5 mg/liter degraded in 15 days after a 4-day lag period), whereas no consumption of MTBE was observed for sediments from the other sites after 75 days. For sediments in which MTBE was consumed, 43 to 54% of added [U-14C]MTBE was mineralized to14CO2. Molecular phylogenetic analyses of these sediments indicated the enrichment of species closely …

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Extended Tailing Of Bacteria Following Breakthrough At The Narrow Channel Focus Area, Oyster, Virginia, Pengfei Zhang, William P. Johnson, Timothy D. Scheibe, Keun-Hyung Choi, Fred C. Dobbs, Brian J. Mailloux Nov 2001

Extended Tailing Of Bacteria Following Breakthrough At The Narrow Channel Focus Area, Oyster, Virginia, Pengfei Zhang, William P. Johnson, Timothy D. Scheibe, Keun-Hyung Choi, Fred C. Dobbs, Brian J. Mailloux

OES Faculty Publications

Extended tailing of low bacterial concentrations following breakthrough at the Narrow Channel focus area was observed for 4 months. Bacterial attachment and detachment kinetics associated with breakthrough and extended tailing were determined by fitting a one-dimensional transport model to the field breakthrough-tailing data. Spatial variations in attachment rate coefficient (k(f)) were observed under forced gradient conditions (i.e., k(f) decreased as travel, distance increased), possibly because of decreased bacterial adhesion with increased transport distance. When pore water velocity decreased by an order of magnitude at 9 days following injection, apparent bacterial attachment rate coefficients did not decrease with velocity as expected …

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Microbial Loop Carbon Cycling In Ocean Environments Studied Using A Simple Steady-State Model, T. R. Anderson, H. W. Ducklow Oct 2001

Microbial Loop Carbon Cycling In Ocean Environments Studied Using A Simple Steady-State Model, T. R. Anderson, H. W. Ducklow

VIMS Articles

A simple steady-state model is used to examine the microbial loop as a pathway for organic C in marine systems, constrained by observed estimates of bacterial to primary production ratio (BP:PP) and bacterial growth efficiency (BGE). Carbon sources (primary production including extracellular release of dissolved organic carbon, DOC), cycling via zooplankton grazing and viral lysis, and sinks (bacterial and zooplankton respiration) are represented. Model solutions indicate that, at least under near steady-state conditions, recent estimates of BP:PP of about 0.1 to 0.15 are consistent with reasonable scenarios of C cycling (low BGE and phytoplankton extracellular release) at open ocean sites …

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A Common Pattern Of Somite Cell Rotation In Three Species Of Pipidae, Shou-Yuan Fan, Rafael O. De Sá, Gary P. Radice Mar 2001

A Common Pattern Of Somite Cell Rotation In Three Species Of Pipidae, Shou-Yuan Fan, Rafael O. De Sá, Gary P. Radice

Biology Faculty Publications

During amphibian somitogenesis, presumptive myotome cells change shape from round or polygonal to elongated and aligned parallel to the notochord (for reviews see Radice, et al., 1989; Keller, 2000). Although the final orientation of myotomal cells is always axial, the movements that achieve this final arrangement can differ greatly between species. The simplest movement is that seen in Bombina variegata, Pelobates fuscus, and Bufo bufo (Brustis et al., 1976; Brustis, 1979; Kielbowna, 1981 ). In these anurans, after segmentation myotomal cells simply elongate along the embryo’s anteroposterior axis. The urodeles Ambystoma mexicanum and Pleurodeles waltl have a very different pattern; …

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Escherichia Coli O157:H7 In Free-Ranging Deer In Nebraska, David G. Renter, Jan M. Sargeant, Scott E. Hygnstrom, Jeff D. Hoffmann, Jerry R. Gillespie Jan 2001

Escherichia Coli O157:H7 In Free-Ranging Deer In Nebraska, David G. Renter, Jan M. Sargeant, Scott E. Hygnstrom, Jeff D. Hoffmann, Jerry R. Gillespie

School of Natural Resources: Faculty Publications

In order to determine the prevalence and distribution of the human pathogen, Escherichia coli O157:H7, in free-ranging deer, hunters were asked to collect and submit fecal samples from deer harvested during a regular firearm season (14–22 November 1998). Prior to the season, 47% of the hunters with permits in the southeastern Nebraska (USA) study area indicated a willingness to participate in the study. Approximately 25% of successful hunters in the area submitted deer fecal samples. Escherichia coli O157:H7 was cultured from four (0.25%) of 1,608 total samples submitted. All of the fecal samples that were properly identified (1,426) and all …

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Short-Term Temporal And Spatial Dynamics Of Bacterioplankton Near Barbados In The Caribbean Sea, Keun-Hyung Choi, Fred C. Dobbs, Robert K. Cowen Jan 2001

Short-Term Temporal And Spatial Dynamics Of Bacterioplankton Near Barbados In The Caribbean Sea, Keun-Hyung Choi, Fred C. Dobbs, Robert K. Cowen

OES Faculty Publications

To investigate temporal (ca 1 mo) and spatial dynamics of bacterioplankton in the Caribbean Sea, time-series measurements of chlorophyll a concentration, bacterial abundance, and thymidine incorporation rate were performed at 6 stations near Barbados, In addition, a series of incubation experiments was carried out with seawater samples collected from various depths and stations to determine bacterial growth rates and removal rates by bacterivory. Vertically integrated phytoplankton and bacterioplankton biomasses averaged 1290 and 1200 mg C m(-2), respectively, and heterotrophic bacterial production was 106 mg C m(-2), with in situ bacterial growth of 0.1 d(-1), Approximately halfway through the sampling period, …

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