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Abstracts
of Recent Publications |
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001
- Aubrey D.N.J. de Grey , Pedro
J.J. Alvarez , Roscoe O. Brady, Ana Maria Cuervo, W.
Gray Jerome, Perry L. McCarty, Ralph A. Nixon, Bruce
E. Rittmann and Janet R. Sparrow (Department of Genetics,
University of Cambridge, Downing Street, Cambridge CB2
3EH, UK). Medical
bioremediation: Prospects for the application of microbial
catabolic diversity to aging and several major age-related
diseases. Ageing
Research Reviews, 4 (2005), 315-338. |
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Several
major diseases of old age, including atherosclerosis,
macular degeneration and neurodegenerative diseases
are associated with the intracellular accumulation of
substances that impair cellular function and viability.
Moreover, the accumulation of lipofuscin, a substance
that may have similarly deleterious effects, is one
of the most universal markers of aging in postmitotic
cells. Reversing this accumulation may thus be valuable,
but has proven challenging, doubtless because substances
resistant to cellular catabolism are inherently hard
to degrade. We suggest a radically new approach: augmenting
humans' natural catabolic machinery with microbial enzymes.
Many recalcitrant organic molecules are naturally degraded
in the soil. Since the soil in certain environments
- graveyards, for example - is enriched in human remains
but does not accumulate these substances, it presumably
harbours microbes that degrade them. The enzymes responsible
could be identified and engineered to metabolise these
substances in vivo. Here, we survey a range of such
substances, their putative roles in age-related diseases
and the possible benefits of their removal. We discuss
how microbes capable of degrading them can be isolated,
characterised and their relevant enzymes engineered
for this purpose and ways to avoid potential side-effects. |
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Keywords:
Aggregates; Lysosomes; Bioremediation;
Bacteria; Catabolism; Atherosclerosis; Neurodegeneration;
Maculardegeneration. |
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002-
Kevin B. Hallberg and D. Barrie
Johnson (School of Biological Sciences, Memorial Building,
Deiniol Road, Bangor, LL57 2UW, UK).Microbiology
of a wetland ecosystem constructed to remediate mine
drainage from a heavy metal mine. Science
of the Total Environment, 338 (2005), 53-66. |
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A
pilot passive treatment plant (PPTP) was constructed
to evaluate the potential of a composite wetland system
to remediate acidic, metal-rich water draining the former
Wheal Jane tin, in Cornwall, England. The treatment
plant consists of three separate and controllable composite
systems, each of which comprises a series of aerobic
wetlands for iron oxidation and precipitation, a compost
bioreactor for removing chalcophilic metals and to generate
alkalinity, and rock filter ponds for removing soluble
manganese and organic carbon. To understand the roles
of microorganisms in remediating acid mine drainage
(AMD) in constructed wetland ecosystems, populations
of different groups of cultivatable acidophilic microbes
in the various components of the Wheal Jane PPTP were
enumerated over a 30-month period. Initially, moderately
acidophilic iron-oxidising bacteria (related to Halothiobacillus
neapolitanus) were found to be the major cultivatable
microorganisms present in the untreated AMD, though
later heterotrophic acidophiles emerged as the dominant
group, on a numerical basis. Culturable microbes in
the surface waters and sediments of the aerobic wetlands
were similarly dominated by heterotrophic acidophiles,
though both moderately and extremely acidophilic iron-oxidising
bacteria were also present in significant numbers. The
dominant microbial isolate in waters draining the anaerobic
compost bioreactors was an iron- and sulfur-oxidising
moderate acidophile that was closely related to Thiomonas
intermedia. The acidophiles enumerated at the Wheal
Jane PPTP accounted for 1% to 25% of the total microbial
population. Phylogenetic analysis of 14 isolates from
various components of the Wheal Jane PPTP showed that,
whilst many of these bacteria were commonly encountered
acidophiles, some of these had not been previously encountered
in AMD and AMD-impacted environments. |
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Keywords:
Acid mine drainage; Acidophiles;
Bioremediation; Iron-oxidising bacteria; Sulfur-oxidising
bacteria; Wetland; Wheal Jane. |
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003-
Michael Kube1, Alfred Beck1, Stephen
H Zinder2, Heiner Kuhl1, Richard Reinhardt1 & Lorenz
Adrian3 (1 Max-Planck-Institut für Molekulare Genetik,
Ihnestr. 63-73, 14195 Berlin-Dahlem, Germany, 2 Dept.
of Microbiology, Cornell University, 272 Wing Hall,
Ithaca, New York 14853, USA. 3 FG Technische Biochemie,
Technische Universität Berlin, Seestr. 13, 13353
Berlin, Germany.ld be addressed to Lorenz Adrian, E-mail:lorenz.adrian@tu-berlin.de).
chlorinated compound-respiring bacterium Dehalococcoides
species strain CBDB1. Nature
Biotechnology, 23(2005), 1269-1273. |
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Dehalococcoides
species are strictly anaerobic bacteria, which catabolize
many of the most toxic and persistent chlorinated aromatics
and aliphatics by reductive dechlorination and are used
for in situ bioremediation of contaminated sites. Our
sequencing of the complete 1,395,502 base pair genome
of Dehalococcoides strain CBDB1 has revealed the presence
of 32 reductive-dehalogenase-homologous (rdh) genes,
possibly conferring on the bacteria an immense dehalogenating
potential. Most rdh genes were associated with genes
encoding transcription regulators such as two-component
regulatory systems or transcription regulators of the
MarR-type. Four new paralog groups of rdh-associated
genes without known function were detected. Comparison
with the recently sequenced genome of Dehalococcoides
ethenogenes strain 195 reveals a high degree of gene
context conservation (synteny) but exceptionally high
plasticity in all regions containing rdh genes, suggesting
that these regions are under intense evolutionary pressure. |
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004-
Greer E. Noonburg and MD. Dr.
Noonburg is (Orthopaedic Surgeon, Memorial Health University
Physicians, Savannah, GA). Management
of Extremity Trauma and Related Infections Occurring
in the Aquatic Environment. Journal
of the American Academy of Orthope- rdic Surgrons,
13 (2005) 4,243-253. |
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Wounds
sustained in oceans, lakes, and streams are exposed
to a milieu of bacteria rarely encountered in typical
land-based injuries. These include Vibrio species, Aeromonas
hydrophila, Pseudomonas and Plesiomonas species, Erysipelothrix
rhusiopathiae, Mycobacterium marinum, and other microbes.
Failure to recognize and treat these less common pathogens
in a timely manner may result in significant morbidity
or death. Initial antibiotic therapy should address
common gram-positive and gram-negative aquatic bacteria,
depending on the environment. Trauma occurring in brackish
or salt water should be treated with doxycycline and
cefiazidime, or a fluoroquinolone (eg, ciprofloxacin
or levofloxacin). Freshwater wounds should be managed
with ciprofloxacin, levofloxacin, or a third- or fourth-
generation cephalosporin (eg, ceftazidime). Injuries
sustained in a marine or freshwater environment may
result from bites or venomous stings of aquatic organisms
as well as from accidental trauma. Musculoskeletal trauma
caused by venomous underwater species (eg, stingrays,
stinging fish, sea urchins, and coral) requires immediate
neutralization of the heat-labile toxin with immersion
in nonscalding water for 30 to 90 minutes. Appropriate
management of aquatic wounds requires recognition of
the mechanism of injury, neutralization of venom, antibiotic
administration, radiographic assessment, surgical debridement
with irrigation, wound cultures, and structural repair
or amputation as indicated by the severity of the injury. |
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Keywords:
Vibrio, Aeromonas hydrophila,
Pseudomonas, Plesfomonas, Mycobacterium marinum,
Microbes |
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005-
Simcha Stroes-Gascoynea. and Julia
M. WestbMicrobial
studies in the Canadian nuclear fuel waste management
program(Atomic
Energy of Canada Limited, Whiteshell Laboratories, Pinawa,
Manitoba ROElLO, Canada, British Geological Survey,
Keyworth, Nottingham, UK). FEMS Microbiology Reviews,
20 (1997),3-4573-590. |
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Atomic
Energy of Canada Limited (AECL) has developed a concept
for pernlanent geological disposal of used nuclear fuel
in Canada. This concept, based on a multibarrier system,
wo~ld involve disposal of nuclear fuel waste in titanium
or copper containers, surrounded by compacted clay-based
buffer and backfill materials, in a vault 500 I 000
m deep in granitic rock of the Canadian Shield. Subsurface
environments will not be sterile and an experimental
program was initiated in 1991 by AECL to address and
quantify the potential effects of microbial action on
the integrity of the disposal vault. This microbial
program focuses on answering specific questions in areas
such as the survival of bacteria in compacted clay-based
buffer materials under relevant radiation, temperature
and desiccation conditions; mobility of microbes in
compacted buffer materials; the potential for microbially
influenced corrosion of containers; microbial gas production
in backfill material; introduction of nutrients as a
result of vault excavation and operation; the presence
and activity of microbes in deep granitic groundwaters;
and the effects of biofilms on radionuclide migration
in the geosphere. This paper summarizes the results
to date from the research activities at AECL. |
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Keywords:
Nuclear waste disposal; Radiation
and desiccation effects; Microbially influenced corrosion;
Radionuclide migration; Gas production. |
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006-
Om V. Singh and Nagathihalli S.
Nagaraj (Park 316, 600 N. Wolfe St, Baltimore, MD 21209,
USA. Tel: 410-614-1804; Fax: 410-955-1030; E-mail: osingh1@jhmi.edu
; ovs11@yahoo.com).Transcriptomics,
proteomics and interactomics: unique approaches to track
the insights of bioremediation Briefings
in Functional Genomics and Proteomics, 4 (2006),
355-362. |
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Microbial
mediated bioremediation has a great potential to effectively
restore contaminated environment, but the lack of information
about factors regulating the growth and metabolism of
various microbial communities in polluted environment
often limits its implementation. Newly seeded techniques
such as transcriptomics, proteomics and interactomics
offer remarkable promise as tools to address longstanding
questions regarding the molecular mechanisms involved
in the control of mineralization pathways. During mineralization,
transcript structures and their expression have been
studied using high-throughput transcriptomic techniques
with microarrays. Generally however, transcripts have
no ability to operate any physiological response; rather,
they must be translated into proteins with significant
functional impact. These proteins can be identified
by proteomic techniques using powerful two-dimensional
polyacrylamide gel electrophoresis (2-DE). Towards the
establishment of functional proteomics, the current
advances in mass spectrometry (MS) and protein microarrays
play a central role in the proteomics approach. Exploring
the differential expression of a wide variety of proteins
and screening of the entire genome for proteins that
interact with particular mineralization regulatory factors
would help us to gain insights into bioremediation.
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Keywords:
bioremediation, transcriptomics,
proteomics, interactomics, pollutants, environmental
cleanup. |
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007-
Sara Di Toro, Giulio Zanaroli
and Fabio Fava (DICASM, Faculty of Engineering, Alma
Mater Studiorum-University of Bologna, Viale Risorgimento
2, I-40136 Bologna, Italy).
Intensification of the aerobic bioremediation
of an actual site soil historically contaminated by
polychlorinated biphenyls (PCBs) through bioaugmentation
with a non acclimated, complex source of microorganisms.
Microbial Cell Factories,
5 (2006), 11. |
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The
biotreatability of actual-site polychlorinated biphenyl
(PCB)-contaminated soils is often limited by their poor
content of autochthonous pollutant-degrading microorganisms.
In such cases, inoculation might be the solution for
a successful bioremediation. Some pure and mixed cultures
of characterized PCB degrading bacteria have been tested
to this purpose. However, several failures have been
recorded mostly due to the inability of inoculated microbes
to compete with autochthonous microflora and to face
the toxicity and the scarcity of nutrients occurring
in the contaminated biotope. Complex microbial systems,
such as compost or sludge, normally consisting of a
large variety of robust microorganisms and essential
nutrients, would have better chances to succeed in colonizing
degraded contaminated soils. However, such sources of
microorganisms have been poorly applied in soil bioremediation
and in particular in the biotreatment of soil with PCBs.
Thus, in this study the effects of Enzyveba, i.e. a
consortium of non-adapted microorganisms developed from
composted material, on the slurry- and solid-phase aerobic
bioremediation of an actual-site, aged PCB-contaminated
soil were studied |
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008-
Yuji Aso, Yukiko Miyamoto, Karen
Mine Harada, Keiko Momma, Shigeyuki Kawai, Wataru Hashimoto,
Bunzo Mikami & Kousaku Murata (Laboratory of Basic
and Applied Molecular Biotechnology & Laboratory
of Food Quality Design and Development, Graduate School
of Agriculture, Kyoto University, Uji, Kyoto 611-0011,
Japan. E-mail: kmurata@kais.kyoto-u.ac.jp).Engineered
membrane superchannel improves bioremediation potential
of dioxin-degrading bacteria. Nature
Biotechnology, 24(2006), 188-189. |
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Sphingomonas
sp. A1 possesses specialized membrane structures termed
'superchannels' that enable the direct incorporation
of macromolecules into the cell. We have engineered
two related sphingomonads, the dioxin-degrading S. wittichii
RW1 and the polypropylene glycol-degrading S. subarctica
IFO 16058T, to incorporate this superchannel into their
cell membranes. In both cases the bioremediation capability
of the organisms was substantially increased pointing
at the potential of this approach as a general strategy
to improve bacterial degradation of hazardous compounds
in the environment |
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009-
Cindy H. Wu, Thomas K. Wood, Ashok
Mulchandani, and Wilfred Chen (Department of Chemical
and Environmental Engineering, University of California,
Riverside, CA 92521. E-mail: Wilfred@engr.ucr.edu).
Engineering Plant-Microbe
Symbiosis for Rhizoremediation of Heavy Metals.
Applied and Environmental
Microbiology, 72 (2006), 1129-1134. |
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The
use of plants for rehabilitation of heavy-metal-contaminated
environments is an emerging area of interest because
it provides an ecologically sound and safe method for
restoration and remediation. Although a number of plant
species are capable of hyper accumulation of heavy metals,
the technology is not applicable for remediating sites
with multiple contaminants. A clever solution is to
combine the advantages of microbe-plant symbiosis within
the plant rhizosphere into an effective cleanup technology.
We demonstrated that expression of a metal-binding peptide
(EC20) in a rhizobacterium, Pseudomonas putida 06909,
not only improved cadmium binding but also alleviated
the cellular toxicity of cadmium. More importantly,
inoculation of sunflower roots with the engineered rhizobacterium
resulted in a marked decrease in cadmium phytotoxicity
and a 40% increase in cadmium accumulation in the plant
root. Owing to the significantly improved growth characteristics
of both the rhizobacterium and plant, the use of EC20-expressing
P. putida endowed with organic-degrading capabilities
may be a promising strategy to remediate mixed organic-metal-contaminated
sites |
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