Soil microcosm

A series of soil microcosms were used to study the biodegradation and bioavailability of pyrene during long-term incubation. The nonextractable fraction of -labeled pyrene that had been introduced into pristine soil and incubated with or without the addition of azide was substantially greater in the latter (Guthrie and Pfaender 1998). It was also shown that microbial activity produced a number of unidentified polar metabolites that might plausibly be involved in the association. 

Morris SA, S Radajewski, TW Willison, JC Murrell (2002) Identification of the functionally active methano-troph population in a peat soil microcosm by stable-isotope probing. Appl Environ Microbiol 68 1446-1453. 

Barriault D, M Sylvestre (1993) Factors affecting PCB degradation by an implanted bacterial strain in soil microcosms. Can J Microbiol 39 594-602. 

Parmelee, R.W., R.S. Wentsel, C.T. Phillips, M. Simini, and R.T. Checkai. 1993. Soil microcosm for testing the effects of chemical pollutants on soil fauna communities and trophic structure. Environ. Toxicol. Chem. 12 1477-1486. 

Microbial mutagenesis Cytotoxicity Fish acute toxicity Algal bioassay Soil microcosm Plant stress ethylene... 

RODENT ACUTE TOXICITY ALGAL BIOASSAY STATIC BIOASSAY SOIL MICROCOSM... 

Two bioassays are employed to evaluate the effect of samples on terrestrial life forms. For gas samples, the plant stress ethylene test is presently recommended. This test is based on the well-known plant response to environmental stress release of elevated levels of ethylene (under normal conditions plants produce low levels of ethylene). The test is designed to expose plants to various levels of gaseous effluents under controlled conditions. The ethylene released during a set time period is then measured by gas chromatography to determine toxicity of the effluent. For liquid and solid samples, a soil microcosm test is employed. The sample is introduced on the surface of a 5 cm diameter by 5 cm deep plug of soil obtained from a representative ecosystem. Evolution of carbon dioxide, transport of calcium, and dissolved oxygen content of the leachate are the primary quantifying parameters. 

Trevors, J. T., van Elsas, J. D., van Overbeek, L. S. Starodub, M-E. (1990). Transport of a genetically engineered Pseudomonas fluorescens strain through a soil microcosm. Applied and Environmental Microbiology, 56, 401-8. 

Over 95% of the hydrocarbon was degraded in 23 weeks in soil microcosm experiments (Table 4.8) that contained added nutrients, Cyanamer P70, and isolated bacteria. 

Based on the successful laboratory soil microcosm experiment, the most heavily contaminated soil was excavated from the surface (2 m) layerand treated ex situ. The soil was placed in an enclosed rectangular bed and its moisture content maintained at 15% (w/w). The soil was aerated with an agricultural spading machine. Surfactant, organic nutrients, and inorganic nutrients were applied to maintain an optimum C N P ratio (data not presented). The isolated microorganisms were inoculated into the soil as dilute suspensions on five separate occasions. 

Havel, J. Reineke, W. (1992). Degradation of Aroclor 1221 and survival of strains in soil microcosms- Applied and Environmental Microbiology, 38, 129-34. 

Naik, G. A., Bhat, L. N., Chopade, B. A. Lynch, J. M. (1994). Transfer of broad-host-range antibiotic resistance plasmids in soil microcosms. Current Microbiology, 28, 209-15. 

Natsch, A., Keel, C., Pfirter, H. A., Haas, D. Defago, G. (1994). Contribution of the global regulator gene gacA to persistence and dissemination of Pseudomonas fluorescens biocontrol strain CHAO introduced into soil microcosms. Applied and Environmental Microbiology, 60, 2553-60. 

Sjogren, R. E. (1994). Prolonged survival of an environmental Escherichia coli in laboratory soil microcosms. Water, Air, and Soil Pollution, 75, 389-403-... 

Soil microcosms with radish seeds planted on top... 

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