Evaluation of aquatic sediment microcosms and their use in assessing possible effects of introduced microorganisms on ecosystem parameters

Journal Article · Wed Apr 01 04:00:00 EST 1992 · Applied and Environmental Microbiology; (United States)

OSTI ID:7303122

Wagner-Doebler, I; Pipke, R; Timmis, K N; Dwyer, D F ^[1]

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1. National Research Center for Biotechnology, Braunschweig (Germany)

In this paper the authors describe a sediment microcosm system consisting of 20 undisturbed, layered sediment cores with overlying site water which are incubated under identical conditions of temperature, light stirring rate of overlying water, and water exchange rate. Ecosystem parameters (nutrient level, photosynthetic potential, community structure of heterotrophic bacterium thymidine incorporation rate, and oxygen microgradients) of the laboratory microcosms and the source ecosystem were compared and shown to be indistinguishable for the first 2 weeks. The microcosm system described here would thus appear to be a valid model of aquatic sediments for up to 4 weeks; the actual period would depend on the sediment source and incubation temperature. The validated systems were used with Rhine river sediment to assess possible effects on ecosystem parameters of Pseudomonas sp. strain B13 FR1(pFRC20P), a genetically engineered microorganism (GEM) survived in the surface sediment at densities of 5 {times} 10{sup 4} to 5 {times} 10{sup 5}/g (dry weight) for 4 weeks and degraded added chloro- and methylaromatics. The GEM did not measurably influence ecosystem parameters such as photosynthesis, densities of selected heterotrophic bacteria, thymidine incorporation rate, and oxygen microgradients. Thus, the microcosm system described here would seem to be useful for the study of the ecology of biodegradation and the fate and effect of microorganisms introduced into the environment.

• OSTI ID: 7303122
• Journal Information: Applied and Environmental Microbiology; (United States), Journal Name: Applied and Environmental Microbiology; (United States) Vol. 58:4; ISSN 0099-2240; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540310* -- Environment
Aquatic-- Basic Studies-- (1990-)
AQUATIC ECOSYSTEMS
AROMATICS
AZINES
BIODEGRADATION
BIOTECHNOLOGY
CHEMICAL REACTIONS
DECOMPOSITION
ECOLOGY
ECOSYSTEMS
ENVIRONMENTAL IMPACTS
GENETIC ENGINEERING
HETEROCYCLIC COMPOUNDS
MICROCOSMS
NUCLEOSIDES
NUCLEOTIDES
NUTRIENTS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PYRIMIDINES
RIBOSIDES
RIVERS
SEDIMENTS
STREAMS
SURFACE WATERS
SYNTHESIS
THYMIDINE
UPTAKE