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Abstracts
of Recent Publications |
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001- Sirpa Metsärinne a, Erja Ronkainen a, Tuula Tuhkanen
b, Reijo Aksela c, Mika Sillanpää (a University
of Kuopio, Department of Environmental Sciences,
P.O. Box 1627, FI-70211 Kuopio, Finland). Biodegradation
of novel amino acid derivatives suitable for complexing
agents in pulp bleaching applications.
Science of the Total Environment, 377
(2007), 45-51.
The biodegradability of four novel diethanolamine
derivative complexing agents was examined by using
two biodegradation tests standardised by OECD
(301B and 301F). Ethylenediaminetetraacetic acid
(EDTA) and diethylenetriaminepentaacetic acid
(DTPA) were employed as reference substances.
Biodegradation of the new complexing agents was
studied both with unacclimated and acclimated
inocula as well as by simulating wastewater treatment
in sequencing batch reactors (SBRs). These new
complexing agents were of technical grade, and
therefore, the results are only indicative but
these new compounds hold promise for use as complexing
agents in the pulp and paper industry. The novel
complexing agents were not readily biodegradable
but they showed slight biodegradation. Around
10-30% degradation was found in the SBR where
degradation was followed by measurement of concentration.
Moreover the novel complexing agents did not have
any negative impact on reactor performance as
measured by chemical oxygen demand reduction.
In the standardised biodegradation tests at best
around 50% degradation was observed with the acclimated
inoculum and in the prolonged test whereas EDTA
and DTPA exhibited no biodegradation. The elevated
degradation in acclimated sludge indicates that
the water treatment plant microbes are capable
of decomposing these molecules under favourable
conditions. The total concentration of novel complexing
agents decreased slightly during biodegradation
tests, while the EDTA and DTPA concentrations
remained stable.
Keywords:
Biodegradation test; Complexing agents; Diethanolamine
derivatives; DTPA; EDTA; Sequencing batch reactor.
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002-Götz
Haferburg a, Martin Reinicke a, Dirk Merten b,
Georg Büchel b, Erika Kothe (a. Friedrich-Schiller-University,
Institute of Microbiology, Microbial Phytopathology,
Neugasse 25, 07743 Jena, Germany). Microbes
adapted to acid mine drainage as source for strains
active in retention of aluminum or uranium.
Journal of Geochemical Exploration, 92
(2007). 196-204.
The use of microorganisms for the extraction of
contaminants like solved metals from drainage
or surface waters was investigated using strains
adapted to a polluted environment at a former
uranium mining site near Kauern, Eastern Thuringia,
Germany. Soil respiration data showed increasing
variation indicating stress response and hence
need for adaptation.
Thus, isolation of single strains was performed
for more detailed analyses. Of the isolated fungi
and bacteria (single-celled bacteria as well as
filamentous actinobacteria), 15 were grown in
mine drainage waters in order to test their capacity
to retain (heavy) metals including rare earth
elements and radioisotopes. Out of the 15 strains
(respectively 5 single-celled bacteria, actinobacteria
and fungi), 11 strains could grow in media containing
acid mine drainage waters diluted by half which
is representative of the conditions a few meters
downstream of the entry point of the acid mine
drainage. Two strains showed promising capacity
for aluminum or uranium retention. Using rare
earth elements as tracers, selective biosorption
or uptake of heavy rare earth elements was prominent
in one sample, a fungal isolate. The actinobacterial
strains also showed capacity for bioremediation
of contaminated seepage waters. Different reactions
to single elements varying between all isolates
indicate biologically controlled transport processes
because such strong fractionation would not be
expected from physico-chemical adsorption processes.
Keywords:
Heavy metals; Rare earth elements; Retention;
Bioremediation; Bacteria; Fungi.
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003-
Susan H. Ferguson a, Shane M. Powell b, Ian Snape
a, John A.E. Gibson c, Peter D. Franzmann d. (a
Department of the Environment and Heritage, Australian
Government Antarctic Division, Kingston, 7050,
Australia b University of Tasmania, Hobart 7001,
Tasmania, Australia c CSIRO Marine Research, GPO
Box 1538, Hobart 7001, Tasmania, Australia d CSIRO
Land and Water, Underwood Ave, Floreat 6014, Western
Australia, Australia). Effect of temperature
on the microbial ecology of a hydrocarboncontaminated
Antarctic soil: Implications for high temperature
remediation. Cold Regions Science
and Technology, 2007.
A series of nutrient-amended microcosms was used
to investigate changing microbial communities
during biodegradation in hydrocarbon-contaminated
Antarctic soils at 4, 10 and 42 °C. Although sample
heterogeneity resulted in no statistically significant
reduction in total petroleum hydrocarbons, biodegradation
ratios indicate significant mineralisation. The
number of culturable bacterial grown at 4 and
10 °C increased from 3×105 g-1 dry soil then peaked
after 5 days incubation at 5×107 g-1 dry soil,
before decreasing to and remaining stable at ca.
2×107 g-1 dry soil. While the bacterial population
grown at 42 °C was initially a minor constituent
of the total culturable bacterial population,
after 40 days there was similar numbers of bacteria
estimated at all temperatures investigated. Denaturing
gradient gel electrophoresis indicated significant
differences in the microbial community between
the 4 and 10 °C and the 42 °C microcosms.
Numerically dominant culturable hydrocarbon degrading
bacteria were isolated at each temperature; 16S
rRNA gene sequences identified the 4 and 10 °C
isolates as Pseudomonas spp., and the
42 °C isolates as Paenibacillus spp.
Fatty acid methyl ester profiles of the cultures
were consistent with these identifications. The
results from this study indicate that bioremediation
treatments will substantially after the soil microbial
ecosystem. All isolates form this study were capable
of growth at 28 oC. The presence of autochthonous
hydrocarbon degrading microbes capable of growth
at higher temperatures introduces the possibility
of in situ remediation treatment options involving
heating (ca. 10-28 oC) to accelerate the rate
of hydrocarbon degradation.
Keywords: Biodegradation;
Microcosms; Petroleum contamination; Paenibacillus
spp.; Pseudomonas spp. DGGE.
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004-Sangjin
Lee. (Research and Development Center, Korea Coast
Guard, 3-8 Bunji, Songdo-Dong, Yunsu-Gu, Incheon
406-130, South Korea). Enhanced dissolution
of TCE in NAPL by TCEdegrading bacteria in wetland
soils. Journal of Hazardous Materials,
145 (2007), 17-22.
The influence of trichloroethene (TCE) dechlorinating
mixed cultures in dissolution of TCE in nonaqueous
phase liquid (NAPL) via biodegradation was observed.
Experiments were conducted in batch reactor system
with and without marsh soils under 10 and 20 ?C
for 2 months. The dissolution phenomenon in biotic
reactors containing mixed cultures was showed
temporal increases compared to abiotic reactors
treated with biocide. Effective NAPL-water transfer
rate (Km) calculated in this study showed more
than four times higher in biotic reactors than
that in abiotic reactors. The results might be
attributed to the biologically enhanced dissolution
process via dechlorination in reactors. Temperature
would be a factor to determine the dissolution
rate by controlling bacterial activity. The TCE
dechlorination occurred even in an interface of
TCE-NAPL that demonstrated no previous TCE biodegradation,
suggesting that microbes may be useful in developing
source-zone bioremediation system. In conclusion,
dechlorinating mixed culture could enhance dissolution
in NAPL that may be useful in the application
of source zone bioremediation.
Keywords:
TCE; Dechlorination; Biodegradation; NAPL (nonaqueous
phase liquid); Dissolution.
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005-Elizabeth
Boddya, Paul W. Hillb, John Farrarb, David L.
Jonesa, (a School of the Environment and Natural
Resources, University of Wales, Bangor, Gwynedd
LL57 2UW, UK bSchool of Biological Sciences, University
of Wales, Bangor, Gwynedd LL57 2UW, UK). Fast
turnover of low molecular weight components of
the dissolved organic carbon pool of temperate
grassland field soils. Soil Biology
& Biochemistry, 39 (2007), 827-835.
Large amounts of low molecular weight (LMW;o250
Da) carbon (C) are lost from roots into the rhizosphere
as a consequence of root turnover and exudation.
Their rates of turnover after release into the
soil remain poorly understood. We extracted soil
solution from a temperate grassland Eutric Cambisol,
isotopically labeled the glucose and amino acid
components, and then re-injected the solution
back into the soil. We followed the subsequent
evolution of 14CO2 and incorporation of the LMW
C into the soil microbial biomass or grasses for
48 h. The experiments were performed both on grazed
and ungrazed swards in the field, and in the laboratory.
In the field, we showed that glucose and amino
acids had short half-lives (t1/2) in soil solution
(t1/2 ¼ 20-40 min), but that they persisted in
soil microbes for much longer. A first-order double
exponential model fitted the experimental data
well and gave rate constant (k) values of 1.21-2.14
h_1 for k1 and 0.0025-0.0048 h_1 for k2. Only
small amounts of the added 14C were recovered
in plant biomass (o5% of total added to soil)
indicating that plant roots are poor competitors
for LMW dissolved organic C (DOC) in comparison
to soil microorganisms. The first phase of glucose
and amino acid mineralization in the laboratory
was slower (t1/2 ¼ 40-60 min) than measured in
the field reinforcing the importance of making
flux measurements in situ. Whilst grazing stimulated
below-ground respiration, it exerted only a small
influence on the turnover of LMW DOC suggesting
that the increase in respiration was due to increased
root respiration and not turnover of soil organic
matter (SOM). Our results suggest that some components
of the LMW DOC pool are turned over extremely
rapidly (ca. 4000 times annually).
Keywords:
Biodegradation; Carbon cycling; Carbon dioxide;
Dissolved organic carbon; Dissolved organic nitrogen;
DOC; DON; Grazing; Mineralization; Rhizodeposition;
Soluble carbon.
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006-Roly
Oliver a, Eric May b, John Williams a. (a Department
of Civil Engineering, University of Portsmouth,
Lion Gate Building, Lion Terrace, Portsmouth,
Hants, PO1 3HF United Kingdom b School of Biological
Sciences, University of Portsmouth, King Henry
Building, King Henry 1 Street, Portsmouth, Hants,
PO1 2DY United Kingdom). Microcosm investigations
of phthalate behaviour in sewage treatment biofilms.
Science of the Total Environment, 372
(2007), 605-614.
Discharge from sewage works has been shown to
be an important source of phthalates into the
environment which is of major concern because
some are toxic, suspected endocrine disruptors
and recalcitrant. Laboratory trickle filter microcosms
(continuous and recirculating flow) were constructed
and operated to investigate the biodegradation
and adsorption of phthalates and also to isolate
phthalate degrading microorganisms. It was found
that adsorption was critical for the removal of
both DEP (77.5%) and DEHP (55.7%) in continuous
flow microcosms. The proportion of phthalates
removed by biodegradation in the continuous flow
microcosms was estimated. Recirculating flow microcosms
improved the removal of DEHP compared to continuous
flow microcosms. Microcosm biofilm used for an
enrichment culture on phthalate media isolated
a varied group of microbes including Gram negative
and Gram positive bacteria, yeasts and fungi.
Bacteria species with all the necessary enzymes
to degrade phthalic acid were isolated.
Keywords:
Phthalate; DEHP; DEP; Microorganisms; Sewage;
Microcosms.
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007-James
P. Amona, Abinash Agrawalb, Michael L. Shelleyc,
Bryan C. Oppermanc, Michael P. Enrighta, Nathan
D. Clemmerc, Thomas Slusserb, Jason Lachb, Teresa
Sobolewskic, William Grunera, Andrew C. Entinghc.
(a Wright State University, Department of Biological
Sciences, Dayton, OH 45435, United States b Wright
State University, Department of Earth & Environmental
Sciences, Dayton, OH 45435, United States c Air
Force Institute of Technology, Department of Systems
& Engineering Management, Graduate School of Engineering,
2950 Hobson Way, Wright- Patterson Air Force Base,
OH 45433, United States). Development
of a wetland constructed for the treatment of
groundwater contaminated by chlorinated ethenes.
Ecological engineering, 3 0 (2 0 0 7),
51-66.
An upward-flowing subsurface supply wetland designed
to mimic natural wetland systems shows evidence
of sequential dechlorination of PCE in contaminated
groundwater. An inherent microzonation in the
rhizosphere of plants that extend roots over 1m
into the soil apparently sustains communities
of microbes responsible for both anaerobic and
aerobic activity. PCE dechlorination and production
of methane near the bottom of the soil column
suggest that anaerobic or reducing conditions
exist there, but core samples indicate roots may
create oxygen-enriched zones throughout the depth
of the wetland. Methane is available to stimulate
oxidative cometabolism via methane monooxygenases
and those enzymes may be responsible for removal
of trichloroethene (TCE) microzones where higher
levels of oxygen is supplied by abundant roots.
Samples taken during different seasons show elevated
degradation during the warmer months but mid-winter
samples show significant removal of PCE and its
breakdown products. Herbaceous plants derived
from local wetland species grew well and did not
appear to be visibly harmed by the PCE or its
by-products.
Core sampling of the root system indicates that
more roots are found when a mixture of wetland
plant species are planted. Benchscale experiments
with 14C labeled TCE show that wetland plants
can also play a role in bioremediation by venting
volatiles to the atmosphere. We suggest that minor
modifications such as increased organic matter
in the soil may lead to more rapid establishment
of wetland performance.
Keywords:
Perchloroethene;Phytoremediation;Bioremediation
Groundwater; Rhizosphere.
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008-Bart
Lievens a,b, Loes Claes b, Matthew S. Krause b,
Alfons C.R.C. Vanachter b, Bruno P.A. Cammue a,
Bart P.H.J. Thomma c . (a Centre of Microbial
and Plant Genetics (CMPG), Katholieke Universiteit
Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee-
Leuven, Belgium b Scientia Terrae Research Institute,
Fortsesteenweg 30A, B-2860 Sint-Katelijne-Waver,
Belgium c Laboratory of Phytopathology, Wageningen
University, Binnenhaven 5, 6709 PD Wageningen,
The Netherlands). Assessing populations
of a disease suppressive microorganism and a plant
pathogen using DNA arrays. Plant
Science, 172 (2007), 505-514.
Understanding the relationships between disease
suppressive microbial populations and plant pathogens
is essential to develop procedures for effective
and consistent disease control. Currently, DNA
array technology is the most suitable technique
to simultaneously detect multiple microorganisms.
Although this technology has been successfully
applied for diagnostic purposes, its utility to
assess different microbial populations, as a basis
for further study of population dynamics and their
potential interactions, has not yet been investigated.
In this study, a DNA macroarray with multiple
levels of phylogenetic specificity was developed
to measure population densities of a specific
disease suppressive microorganism, Trichoderma
hamatum isolate 382, and the plant pathogen Rhizoctonia
solani. Amongst others, the DNA array contained
genus-, species- and isolate-specific detector
oligonucleotides and was optimized for sensitive
detection and reliable quantification of the target
organisms in potting mix samples. Furthermore,
this DNA array was used to quantify disease severity
as well as incidence of severe disease based on
pathogen population densities in the growing medium.
Taking into account the unlimited expanding possibilities
of DNA arrays to include detector oligonucleotides
for other and more microorganisms, this technique
has the potential for studying the population
dynamics and ecology of several target populations
in a single assay.
Keywords:
Biological control; Disease management; Integrated
pest management (IPM); Multiplex; Reverse dot
blot; Quantification.
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009-Jong-Shik
Kima, Gerd Sparovekb, Regina M. Longoc, Wanderley
Jose De Meloc,David Crowleya,. (a Department of
Environmental Sciences, University of California,
Riverside, CA, USA bDepartment of Soil Science,
ESALQ, University of Sao Paulo, Piracicaba CP
9, CEP 13418-900, Brazil cDepartment of Technology,
Universidade Estadual Paulista, Jaboticabal, SP,
CEP 14884-900, Brazil). Bacterial diversity
of terra preta and pristine forest soil from the
Western Amazon. Soil Biology & Biochemistry,
39 (2007), 684-690.
The survey presented here describes the bacterial
diversity and community structures of a pristine
forest soil and an anthropogenic terra preta from
the Western Amazon forest using molecular methods
to identify the predominant phylogenetic groups.
Bacterial community similarities and species diversity
in the two soils were compared using oligonucleotide
fingerprint grouping of 16S rRNA gene sequences
for 1500 clones (OFRG) and by DNA sequencing.
The results showed that both soils had similar
bacterial community compositions over a range
of phylogenetic distances, among which Acidobacteria
were predominant, but that terra preta supported
approximately 25% greater species richness. The
survey provides the first detailed analysis of
the composition and structure of bacterial communities
from terra preta anthrosols using noncultured-based
molecular methods.
Keywords:
Bacterial diversity; Forest soils; Microbial ecology;
Terra preta.
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010-Brandon
Clark, Raj Boopathy. (Department of Biological
Sciences, Nicholls State University, Thibodaux,
LA 70310, USA). Evaluation of bioremediation
methods for the treatment of soil contaminated
with explosives in Louisiana Army Ammunition Plant,
Minden, Louisiana. Journal of Hazardous
Materials, 143 (2007), 643-648.
Two bioremediation methods, namely, soil slurry
reactor and land farming technique were evaluated
for the treatment of soil contaminated with explosives
in Louisiana Army Ammunition Plant, Minden, Louisiana.
The soil had a high concentration of 2,4,6- trinitrotoluene
(TNT) of 10,000 mg/kg of soil and medium level
contamination of RDX 1900 mg/kg andHMX900 mg/kg
of soil. The results indicated that soil slurry
reactor under co-metabolic condition with molasses
as co-substrate removed TNT more efficiently than
land farming method. TNT removal efficiency was
99% in soil slurry reactor compared to 82% in
land farming after 182 days. HMX and RDX were
also removed from the soil in both methods, but
the removal efficiency was low. The radiolabeled
study showed that soil microbes mineralize TNT.
The mass-balance of TNT indicated 23.5% of TNT
was mineralized to CO2, 22.6% was converted to
biomass, and 52.3% was converted to various TNT
intermediates in the soil slurry reactor. Both
methods maintained high bacterial population fairly
well. The results of this bench-scale study are
promising with regard to transferring the technology
to full-scale application at this site.
Keywords:
TNT; Soil slurry; Land farming; Bioremediation;
Cometabolism; Co-substrate.
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011-Carey
K. Bagdassariana, Amy E. Dunhamb,1, Christopher
G. Browna,2, Daniel Rauschera,2. (a Department
of Chemistry, College of William and Mary, P.O.
Box 8795, Williamsburg, VA 23187-8795, USA bDepartment
of Organismic and Evolutionary Biology, Harvard
University, Harvard University Herbaria, 22 Divinity
Avenue, Cambridge, MA 02138, USA). Biodiversity
maintenance in food webs with regulatory environmental
feedbacks. Journal of Theoretical
Biology, 245 (2007), 705-714.
Although the food web is one of the most fundamental
and oldest concepts in ecology, elucidating the
strategies and structures by which natural communities
of species persist remains a challenge to empirical
and theoretical ecologists. We show that simple
regulatory feedbacks between autotrophs and their
environment when embedded within complex and realistic
food-web models enhance biodiversity. The food
webs are generated through the niche-model algorithm
and coupled with predator-prey dynamics, with
and without environmental feedbacks at the autotroph
level. With high probability, especially at lower,
more realistic connectance levels, regulatory
environmental feedbacks result in fewer species
extinctions, that is, in increased species persistence.
These same feedback couplings, however, also sensitize
food webs to environmental stresses leading to
abrupt collapses in biodiversity with increased
forcing. Feedback interactions between species
and their material environments anchor food-web
persistence, adding another dimension to biodiversity
conservation. We suggest that the regulatory features
of two natural systems, deep-sea tubeworms with
their microbial consortia and a soil ecosystem
manifesting adaptive homeostatic changes, can
be embedded within niche-model food-web dynamics.
Keywords:
Environmental feedbacks; Food webs; Predator-prey
dynamics; Niche model; Species persistence.
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012-Susan
H. Ferguson a, Shane M. Powell b, Ian Snape a,
John A.E. Gibson c, Peter D. Franzmann d (a Department
of the Environment and Heritage, Australian Government
Antarctic Division, Kingston, 7050, Australia
b University of Tasmania, Hobart 7001, Tasmania,
Australia c CSIRO Marine Research, GPO Box 1538,
Hobart 7001, Tasmania, Australia d CSIRO Land
and Water, Underwood Ave, Floreat 6014, Western
Australia, Australia). Effect of temperature
on the microbial ecology of a hydrocarboncontaminated
Antarctic soil: Implications for high temperature
remediation. Cold Regions Science
and Technology , (2007).
A series of nutrient-amended microcosms was used
to investigate changing microbial communities
during biodegradation in hydrocarboncontaminated
Antarctic soils at 4, 10 and 42 °C. Although sample
heterogeneity resulted in no statistically significant
reduction in total petroleum hydrocarbons, biodegradation
ratios indicate significant mineralisation. The
number of culturable bacterial grown at 4 and
10 °C increased from 3×105 g- 1 dry soil then
peaked after 5 days incubation at 5×107 g- 1 dry
soil, before decreasing to and remaining stable
at ca. 2×107 g- 1 dry soil. While the bacterial
population grown at 42 °C was initially a minor
constituent of the total culturable bacterial
population, after 40 days there was similar numbers
of bacteria estimated at all temperatures investigated.
Denaturing gradient gel electrophoresis indicated
significant differences in the microbial community
between the 4 and 10 °C and the 42 °C microcosms.
Numerically dominant culturable hydrocarbon degrading
bacteria were isolated at each temperature; 16S
rRNA gene sequences identified the 4 and 10 °C
isolates as Pseudomonas spp., and the
42 °C isolates as Paenibacillus spp.
Fatty acid methyl ester profiles of the cultures
were consistent with these identifications. The
results from this study indicate that bioremediation
treatments will substantially alter soil microbial
ecosystem. All isolates from this study were capable
of growth at 28 °C. The presence of autochthonous
hydrocarbon degrading microbes capable of growth
at higher temperatures introduces the possibility
of in situ remediation treatment options involving
heating (ca. 10-28oC) to accelerate the rate of
hydrocarbon degradation.
Keywords:
Biodegradation; Microcosms; Petroleum contamination;
Paenibacillus spp.; Pseudomonas
spp. DGGE.
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| ENVIS
CENTRE Newsletter Vol.5, July 2007 |
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