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The effectiveness of three dispersants to modify slurry rheology was examined using rheology measurements and laser scanning confocal microscopy (LSCM) in simulated waste solutions. All of the dispersants lowered the yield stress of the slurries below the baseline samples. The rheology curves were fitted reasonably to a Bingham Plastic model. The three-dimensional LSCM images of simulants showed distinct aggregates were greatly reduced after the addition of dispersants leading to a lowering of the yield stress of the simulated waste slurry solutions.

The presence and density of methanotrophic bacteria has been shown to play an important role in the bioremediation of trichloroethylene (TCE). This article describes the methanotrophic bacterial densities in rhizosphere soils from two areas of the Department of Energy's Savannah River Site in Aiken, South Carolina. A direct fluorescent antibody (DFA) technique was evaluated to determine the presence of methanotrophic bacteria in roots and rhizospheres from vascular plants. The first site, the Miscellaneous Chemical Basin (MCB), was contaminated with a mixture of chemicals, including chlorinated solvents. The second site will be potentially affected by outcropping of TCE-contaminated groundwater. Significantly higher numbers of methanotrophic bacteria were observed with DFA in rhizosphere soils and on roots of Lespedeza cuneata and Pinus taeda (that previously showed higher rates of 14C-TCE mineralization) compared with nonvegetated soils. In addition, viable and heterotrophic microbial counts wer...

Extensive trichloroethylene (TCE) groundwater contamination has resulted from discharges to a former seepage basin in the A/M Area at the Department of Energy's Savannah River Site. The direction of groundwater flow has been determined and a seep line where the contaminated groundwater is estimated to emerge as surface water has been identified in a region of the Southern Sector of the A/M Area. This study was undertaken to estimate the potential of four rhizosphere soils along the seep line to naturally attenuate TCE. Microcosms were setup to evaluate both biotic and abiotic attenuation of TCE. Results demonstrated that sorption to soil was the dominant mechanism during the first week of incubation, with as much as 90% of the TCE removed from the aqueous phase. Linear partitioning coefficients (Kd) ranged from 0.83 to 7.4 mL/g, while organic carbon partition coefficients (Koc) ranged from 72 to 180 mL/gC. Diffu-sional losses from the microcosms appeared to be a dominant fate mechanism during the remainde...

Thiothrix spp., sulfide‐oxidizing mixotrophic bacteria, were sampled from visible colonies in the Floridan aquifer in several underwater caves, sinkholes, and springs below the water table in North Florida. Bacteria samples were collected by cave divers certified by the National Speleological Society/Cave Diving Section. Sites sampled were ecological niches in the aquifer where visible colonies had a white slimy or filamentous appearance indicative of Thiothrix spp. Sterile sampling methods were adapted to the underwater cave setting. Bulk water samples for media preparation were collected by divers from bacteria sampling sites. Bacteria were isolated and cultured in growth media prepared with cave or spring water. Thiothrix spp. were identified by microbiological and immunological methods. Monoclonal antibodies specific for Thiothrix spp. were utilized in fluorescent antibody assays and enzyme‐linked im‐munosorbent assays (ELISA). Thiothrix was found in six of eight underwater caves sampled. Three of the...

β-Hydroxybutyrate and routine biochemical parameters were determined on plasma and urine samples obtained from free-ranging desert tortoises over a 1-year period. Urea nitrogen varied inversely with total protein concentration (P

We have developed a method to enrich, isolate, and identifyThiothrix spp. in environmental samples. This procedure employs low concentrations of organic compounds, the addition of reduced sulfur compounds (sulfide or thiosulfate), and preparation with spring water that containsThiothrix spp. The enrichment enhanced identification ofThiothrix spp. by promoting deposition of intracellular sulfur granules and inhibiting overgrowth by other bacteria. The relatively high calcium content of the spring water contributed to the culture procedure. With this technique,Thiothrix spp. were observed in two activated sludge systems, a municipal water storage tank, three springs, and four underground freshwater caves in the phreatic zone of the Floridan aquifer. Two differentThiothrix cultures have been isolated from a freshwater cave and a water storage tank by this procedure. It appears that media prepared with spring water known to supportThiothrix spp. can be designed to provide highly selective methods for isolation ofThiothrix spp. from a wide range of environments.

1. 1. The relationship between seasonal changes in environmental temperature and hematological parameters was investigated in mature, single comb white leghorn (SCWL) male chickens. 2. 2. Samples of blood plasma, obtained monthly from two groups of birds over two separate 12 month periods, were analysed for corticosterone (CT), 3,5,3′-triiodothyronine (T3), thyroxine (T4), plasma protein (PP), and packed cell volume (PCV). 3. 3. Statistical analyses revealed that blood plasma concentrations of T3 were significantly correlated negatively with monthly dry-bulb temperatures. 4. 4. There were no consistent or significant relationships between monthly dry-bulb temperature and CT, T4, PP or PCV over the two 12 month periods. 5. 5. The results of this study indicate that blood plasma concentrations of T3 are influenced by season of year in mature, male domestic fowl.

An automated method for measuring beta-hydroxybutyrate was adapted to the Ciba-Corning 550 Express trade mark random access analyzer. The assay was based on a kinetic reaction utilizing hydroxybutyrate-dehydrogenase. Beta-hydroxybutyrate concentration (mmol/L) was calculated ratiometrically using a 1.0 mmol/l standard. Canine serum, plasma, and urine were used without prior deproteinization and only a 30-microliter sample was required. The method demonstrated good linearity between 0 to 2 mmol/l of beta-hydroxybutyrate. Analytical recovery (accuracy) within these concentrations ranged from 85.8 to 113.3%. Both within-run and day-to-day precision were determined, as was specificity of the assay in the presence of a variety of interfering substances. The automated assay was rapid and economical, with reagent stability maintained for at least 2 weeks at 4 degrees C. This assay can readily be applied toward the assessment of ketoacidosis in dogs, and with further validation, other species.

In a practical sense, biotechnology is concerned with the production of commercial products generated by biological processes. More formally, biotechnology may be defined as "the application of scientific and engineering principles to the processing of material by biological agents to provide goods and services" (Cantor, 2000). From a historical perspective, biotechnology dates back to the time when yeast was first used for beer or wine fermentation, and bacteria were used to make yogurt. In 1972, the birth of recombinant DNA technology moved biotechnology to new heights and led to the establishment of a new industry. Progress in biotechnology has been truly remarkable. Within four years of the discovery of recombinant DNA technology, genetically modified organisms (GMOs) were making human insulin, interferon, and human growth hormone. Now, recombinant DNA technology and its products--GMOs are widely used in environmental biotechnology (Glick and Pasternak, 1988; Cowan, 2000). Bioremediation is one of the most rapidly growing areas of environmental biotechnology. Use of bioremediation for environmental clean up is popular due to low costs and its public acceptability. Indeed, bioremediation stands to benefit greatly and advance even more rapidly with the adoption of molecular techniques developed originally for other areas of biotechnology. The 1990s was the decade of molecular microbial ecology (time of using molecular techniques in environmental biotechnology). Adoption of these molecular techniques made scientists realize that microbial populations in the natural environments are much more diverse than previously thought using traditional culture methods. Using molecular ecological methods, such as direct DNA isolation from environmental samples, denaturing gradient gel electrophoresis (DGGE), PCR methods, nucleic acid hybridization etc., we can now study microbial consortia relevant to pollutant degradation in the environment. These techniques promise to provide a better understanding and better control of environmental biotechnology processes, thus enabling more cost effective and efficient bioremediation of our toxic waste and contaminated environments.

Intrinsic bioremediation is a risk management option that relies on natural biological and physical processes to contain the spread of contamination from a source. Evidence is presented in this report that intrinsic bioremediation is occurring at the Sanitary Landfill is fundamental to support incorportion into a Corrective Action Plan (CAP).

An ELISA previously developed for the rapid detection of Salmonella enteritidis (SE) in environmental samples was modified and applied to food samples. A sandwich ELISA was designed that employs affinity-purified rabbit polyclonal antibodies for the capture stage and highly specific monoclonal antibodies for the detection stage. Thirty-nine species of bacteria other than SE, including 32 Salmonella species, were included in cross-reactivity testing with ELISA. Results showed no reactivity with any species tested besides SE. Salmonella enteritidis was added to homogenized food samples (chicken skin, meat, and eggs) to test ELISA sensitivity. The lower limit for ELISA detection of SE was 10(4) cells/mL for pure cultures and in 10% meat (wt/vol), 10(5) cells/mL in 10% skin (wt/vol), and 10(7) cells/mL in 10% eggs (wt/vol). Salmonella enteritidis detection with ELISA was confirmed with the Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) method. Results were obtained within 24 h for ELISA method compared to 96 h for the BAM procedure. Results show that sensitivity of ELISA can vary with the type of food tested for detection of SE.

Historically, methods used to identify Thiothrix spp. in environmental samples have been inadequate because isolation and identification procedures are time-consuming and often fail to separate Thiothrix spp. from other filamentous microorganisms. We described a monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) procedure which was used to identify Thiothrix spp. in wastewater, artesian springs, groundwater, and underwater subterranean samples. The ELISA utilized monoclonal antibody T3511 to a species-specific carbohydrate epitope of Thiothrix spp. No cross-reactions were observed among non-Thiothrix strains consisting of 12 species and nine genera. In field trials, the ELISA identified 100% of 20 biochemically and cytologically confirmed Thiothrix spp.-containing samples with no false positives. Indirect immunofluorescent microscopy utilizing T3511 was effective for wastewater samples but not for those from natural spring water because of background fluorescence in the latter. In addition, electron micrographs of Thiothrix spp. labeled with T3511-biotin-anti-mouse antibody-gold showed that epitope T3511 was intracellular both in laboratory strains and environmental isolates. The minimum level of detection of the ELISA was 0.10 microgram/ml.

Heart rates were obtained simul- taneously from FM radio transmitters and heart rate monitors externally mounted on unanesthe- tized and unrestrained mixed-breed goats. Data from transmitters were highly correlated (r = .92, P < .0001) with data from monitors and the heart rates. percentage difference in heart rates between the two devices was less than that observed between animals. Analyses also revealed that radio trans- mitters provided a reliable, repeatable, and valid method for the noninvasive measurement of goat

We have developed a enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody (ASCII) for the detection of Salmonella enteritidis in environmental samples. ELISA was used to test for sensitivity and specificity of ASCII. 38 other species of bacteria, including 31 Salmonella species were included in cross-reactivity testing with ELISA. ASCII showed no reactivity with any other species tested. ASCII was found to be an IgG1 specific for S. enteritidis lipopolysaccharide (LPS). The lower limits for S. enteritidis detection was 10(5) cells/ml for pure cultures and in 10% sludge (w/v). Environmental samples (raw wastewater, wastewater effluents, mixed liquor and aerobically digested sludge) were obtained twice from five sites and ELISA tested for the presence of S. enteritidis. ELISA results compared to the American Public Health Association (APHA) method of Salmonella detection were not significantly different (P greater than 0.05). The ELISA took 24 h for completion compared to 96-120 h for the APHA procedure. Results demonstrate the reliability of the ELISA and, more importantly, provides a rapid means of detection of S. enteritidis in environmental samples.

Eight adult New Zealand White rabbits were exposed individually, in series, to each of 23 effective temperatures (t(eff)) until body temperature (tb) increased 1.1 degrees C or for a period of 2 hours. Body temperature was measured to the nearest 0.1 degree C using FM radio transmitters in the pre-test (baseline) condition and at 2 minute intervals during the test conditions where t(eff) ranged between 21.7 and 34.7 degrees C. The frequency at which the rabbits displayed a 1.1 degree C rise in tb was related to the magnitude of the t(eff), with 100% of the rabbits manifesting this change at t(eff) greater than 30.2 degrees C. At t(eff) of 28.4 through 30.2 degrees C, some, but not all, of the rabbits showed a 1.1 degree C rise in tb whereas none displayed the 1.1 degree C rise in tb at t(eff) below 28.4 degrees C. The mean time necessary for the 1.1 degree C rise in tb was negatively correlated (P less than 0.01) to the magnitude of the t(eff). The significantly (P less than 0.01) elevated plasma corticosterone in rabbits exhibiting 0.6 degree C and 1.1 degree C rise in tb suggests that those animals were stressed physiologically by the experimental procedure. It is concluded that the conditions associated with increased tb induce physiological changes commonly associated with stressors and that the techniques reported herein should be useful in establishing upper environmental temperature limits for housing rabbits.

An inexpensive but reliable telemetry system for long-term, sequential monitoring of body temperature in up to 20 laboratory animals is described. The system consists of frequency-modulated (FM) temperature transmitters, remote-controlled power switches to extend battery life, a multi-channel telemetry receiver, and a frequency counter interfaced with a personal computer to record data. Analysis of body temperature data obtained from four New Zealand White rabbits confirms the reliability and value of this system.

Four groups of 70-wk-old broiler breeder females were fed once daily at 0600, 1000, 1400, and 1800 h to determine the effect of feeding time and eating on body temperature. The photoperiod was from 0430 to 1930 h. Four floor pens of 30 hens each were assigned per feeding time. Following a 9-day adjustment period, body temperature was determined, in series, by rectal probe of 5 birds/pen at 7 and 3 h prefeeding and 1, 5, 9, and 13 h postfeeding. Body temperature was increased .5 C at 1 h postfeeding in all groups and at 5 h postfeeding in the 0600-h fed group. The rate of feed consumption was fastest with afternoon feeding. Four 1-yr-old broiler breeder males were implanted with an FM radio transmitter for monitoring body temperature and housed in an environmental control chamber. Body temperature was monitored when the birds were fed at 0600, 1000, 1400, and 1800 h. The chamber temperature cycled from 22.2 to 33.3 C (22.2 C: 2200 to 0800 h; 33.3 C: 1200 to 1600 h; 27.8 C: 0800 to 1200 h and 1600 to 2200 h). Lights were on from 0430 to 1930 h. Body temperature changes were also monitored under constant temperature (27.8 C) and light for birds fed ad libitum or at 1000 h. Body temperature increased as much as 1.5 C following feeding and reached a maximum at 5, 4, 3, and 2 h postfeeding at feeding times of 0600, 1000, 1400, and 1800 h, respectively. Males unable to feed displayed a significantly increased body temperature when they observed other birds eating. A specific body temperature response to feeding activity was observed only when males were fed once daily under constant environment.