Number: 1999-013-2-600
Title: Soil and water bio-remediation: in-situ treatment of
polluted soil and water with emphasis on the use of genetically engineered
microorganisms
Task Group
Chairman: R.
Mandelbaum
Members:
W. Kordel, R.J. Wright, W.J.M. Peijnenburg, Y. Shevah, U. Mingelgrin,
and S. Koeningsberg
Completion Date: 2003 - project abandoned
Objective:
To prepare a critical review and the state-of-the-art of the removal
of hazardous chemical contaminants from the liquid, solid and gas phases
using biological processes, including bioremediation of leachates, soils
and sediments. Emphasis will be given to novel application of genetically
engineered microorganisms for bioremediation.
The issue of gene transfer in the environment and the relevance of
genetically engineered microbes to environmental risk assessment will
be evaluated, together with the related complexity that they add to
the overall remediation process. Lack of knowledge regarding microbial
community interactions with the ecology and the potential for adverse
ecological and human health effects is a significant environmental concern.
Description:
Bioremediation is considered a potentially advantageous technique
for the treatment of hazardous wastes and is considered as a primary
or ancillary cleanup technology, employing state of the art solutions.
A state-of-the-art description of advances in pollution treatment and
reduction using biological means was given by Sikdar and Irvine 1998,
describing new development at the regulatory and the removal of contaminants
from the liquid, solid and gas phase and all media - air, water and
soil/sediment. Cleaning of contaminated sites are the subject of in
situ and ex situ treatment as discussed by Porta (1991) and Science
(1992), while soil and groundwater are the media most frequently treated
with bioremediation technology (Shevah and Waldman, 1995).
Remediation technologies include advanced remediation technologies
using nutrient and micro organisms addition to simulate biomass and
combination of techniques are being evaluated including:
- re-introduction of enhanced environmental isolates acclimated to
target chemicals
- stimulation of degradation by addition of surfactants detergents
to increase bio-availability of chemicals
- adaptation of aerobic micro organisms to low oxygen environments
Of the above techniques, the application of genetically engineered
microorganisms for bioremediation construct the potential of indigenous
species with previously unavailable genes, acquiring new expression
potential, as extensively discussed by Miller and Levy (1989). However,
as with any technological tools, the unintended consequences of the
application of this technology are not clear. The possible adverse effects
of bioremediation to ecological systems are difficult to assess regardless
of whether the potential impacts are due to the engineered remediation
application, because the local ecology of the selected site has already
been adversely altered by the acute or chronic contamination (Reisman,
Claxton and Harvey, 1998).
Human health risks from bioremediation are also becoming better defined
and risks from microorganisms used for bioremediation or from metabolites
produced from bioremediation of waste chemicals include direct health
effects such as toxicity, infectivity, pathogenenicity and allergenicity
and indirect effects such as cyto-toxicity and carcinogenecity. Microbes
could also pose a threat as vectors for foreign genes.
In the proposed review, the application of genetically engineered microorganisms
will be critically reviewed with regards to the following:
- organism stability, persistence and mobility
- potential to grow in population size
- effects within the soil microbial community
- chemical degradation, transformation and clean-up effects on the
ecosystem
Progress:
project abandoned
Last Update: 2 July 2004
<project announcement published in
Chem.
Int.
22(6) 2000>
If
you want to update this information, contact us by e-mail
Do not forget to include the Project Number,
your name and relation with that project