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Microbial eukaryotes in oilsandsassociated environments of Northern Alberta

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6
· “PROTIST–2016”
belonging to Spirotrichs. Maximum number of
oxytrichids were found in Rithala sewage site though
ciliate diversity was less. Maximum ciliate diversity
was found in ANDC whereas ciliate diversity was
less in Karnal. Colpodids were present in all the
sites examined but most abundant in sewage site.
Variation in soil ciliate diversity can be correlated
with soil quality of studied habitats.
SOIL PROTIST BACTERIA CONSUMPTION IS
CENTRAL TO NUTRIENT CYCLING
Adl S.M.
University of Saskatchewan
sina.adl@usask.ca
Protists are the most abundant consumers of
bacteria in soils. Their diversity covers most
lineages making them the most diversity group of
organisms in soils. Communities assemble along
abiotic microgradients, such as pO2, pCO2, pH,
temperature, etc. Species of protist bacterivores
are not homologous or interchangeable. Species
in functional groups have differing ecological
preferences, occupying distinct niches. There are
significant measurable species specific differences
regarding prey ingestion rates and prey preferences.
It has been well recognised in both soil and aquatic
ecology that ignoring inter-species variability in
behaviour and consumption rates is problematic.
The top-down grazing pressure on bacteria was
calculated for a variety of species representing a
variety of feeding types, from functional response
curves. We calculated threshold prey levels that
sustained growth and initial rate slopes for ingestion
rates, to compare competitive ability at low food
conditions. Together with maximum growth rates
and maximum ingestion rates inter-specific competitiveness and niche preferences could be distinguished. Data will be presented for several well
established cercozoa cultures, amoebae cultures,
ciliates, and other protists. This information helps to
improve our calculations of global bacteria biomass
turnover rates in soils. It also helps to understand
how soils can support dozens of bacterivorous
species in each gram of soil, in a seemingly similar
habitat.
BIODIVERSITY STUDIES IN LORICATE
PROTISTS: THE CASE OF TINTINNIDS (ALVEOLATA, CILIOPHORA, SPIROTRICHA)
Agatha S.1, Santoferrara L.F.2
1
- Dept. of Ecology and Evolution, University of
Salzburg, Salzburg, Austria
2
- Dept. Marine Sciences, University of Connecticut,
Groton, Connecticut, USA
sabine.agatha@sbg.ac.at
Species identification is crucial in biodiversity
research (ecology, taxonomy, barcoding etc.).
In tintinnids, taxonomy and classification are
almost exclusively based on features of their vaseshaped loricae (houses). The lorica-based species
circumscriptions are, however, problematic as
loricae might show a considerable intraspecific
variability and interspecific similarity and might
be influenced by the cell cycle and physicochemical factors. To overcome the difficulties
with deviating species limitations suggested by
“lumpers” or “splitters” in revisionary treatises, it
is recommend to “go back to the roots”, i.e., to use
exclusively the original descriptions or authoritative
redescriptions for identification. Additionally,
good documentation of the identified loricae by
means of illustrations and morphometric data is
advisable. Depending on the aim of the tintinnid
study, further procedures are proposed to generate
at high rates long-lasting high-quality species re-/
descriptions and/or DNA barcodes, which are
essential for reliable phylogenetic analyses and thus
for the establishment of a natural tintinnid classification. These suggestions represent a compromise
between data quality and work effort and can most
easily be followed by collaborations of molecular
biologists and morphologic taxonomists. Financially
supported by FWF project P28790.
MICROBIAL EUKARYOTES IN OILSANDSASSOCIATED ENVIRONMENTS OF NORTHERN ALBERTA
Aguilar M.1, Richardson E.1, Paoli L.2, Nesbo C.3,
Foght J.3, Dunfield P.F.4, Dacks J.B.1,5
1
- Department of Cell Biology, University of Alberta.
Edmonton, Canada
2
- Département de Biologie, Ecole normale supérieure,
Paris, France
3
- Department of Biological Sciences, University of
Alberta, Edmonton, Canada
4
- Department of Biological Sciences, University of
Calgary, Calgary, Canada
5
- Department of Life Sciences, Natural History
Museum, London, UK
dacks@ualberta.ca
The oil sands in Northern Alberta are the second
largest bitumen deposit in the world, and comparable
in magnitude to world’s reserves of conventional
petroleum. They have global significance as energy
reservoirs. However, some aspects of their exploitation are also cause for environmental concern.
Fluid wastes from bitumen extraction are retained
in enormous tailings ‘ponds’ under a policy of no
release to the environment. The estimated surface
area of tailings ponds in Alberta ranges from 77-176
Protistology
km2. Thus, since their commissioning approximately
five decades ago, the ponds have accumulated
anoxic, brackish, hydrocarbon and heavy metal
containing sediments overlain by a thinner layer
of process-affected water that may be oxic near the
surface. Microbial processes are anticipated to play
a major role in remediation of these environments,
and, although the prokaryotic communities are
increasingly well-characterized, little is known about
the microbial eukaryotes present in the oxic and
anoxic environments. We have recently reported the
first NGS-based exploration of protists in tailings
ponds. We found that, despite the anoxic and
hydrocarbon-enriched nature of the environment,
the tailings ponds harbour complex communities of
microbial eukaryotes indicating that these organisms
should be taken into account when studying the
microbiology of the oil sands.
NOVEL PICOPLANKTONIC GROUPS FROM
LAKE BAIKAL REVEALED BY MASSIVE SEQUENCING
Annenkova N.V.1, Logares R.2
1
- Limnological Institute SB RAS, Russia
2
- Institute of Marine Sciences, CSIC, Spain
tasha.annenkova@gmail.com
Compared to the ocean, freshwater systems offer
multiple ecological niches in terms of oxygen and
DOC concentrations, light accessibility, temperature
variability. However, we are still limited by the data of
freshwater microbes biodiversity. Studies are highly
biased because correspond mainly to Europe and
North America. In particular, studies of Northern
Asian protists are very limited, though this region
extends on about 8000 km in length and has a big
impact on microorganisms’ migrations. Lake Baikal
is the oldest and deepest lake in the world, being
located in Northern Asia. It is cold, oxygen rich,
and has one of the world richest endemic freshwater
biotas, belonging both to very ancient lineages and
to recent immigrants. Our goal was to explore small
planktonic protists populating the lake. The genetic
diversity (V4 region of the 18S rDNA) of planktonic
microeukaryotes (< 8 µm fraction) was analyzed
in 48 samples using the Illumina MiSeq platform.
We determined 1,461 protist OTUs, with 9.6% of
them having less than 90% similarity with sequences
from SILVA database. We suggest that they belong
to endemic Baikal protists. We analyzed the
phylogenetic relationships of groups such as MAST,
Telonemiidae, Perkinsiidae, Chitridiomycota
which were not previously described in Lake Baikal.
Interestingly, we found Amoebophrya-like 18S
rDNA in Baikal, even though Syndiniales were not
reported from freshwaters. Overall, the most diverse
· 7
group was stramenopiles. This study contributes
to improve our understanding of the diversity of
protist communities living in ancient lakes as well
as to comprehend better intra-lake evolutionary
diversification processes.
Supported by project of RAS # 0345–2014–0003
MODELLING THE LOCAL-TO-GLOBAL DIVERSITY FOR MICROBES AND MULTICELLULARS: COULD WE ESTIMATE THE
NEAR-IMPONDERABLE?
Azovsky A.I.
Lomonosov Moscow State University, Moscow, Russia
aiazovsky@mail.ru
In the current discussion around either “protist
diversity is different” or not, the ratios of local:global
diversity and relative endemicity are often treated as
arguments. This approach has, however, been flawed
by the fact that actual global diversity of protists is
still largely unknown, especially for the rare species.
I use simple models to simulate distribution of
species on the 400-cell lattice. Three models have
been considered:
1) “Everything is everywhere” (equal probability for
a particular species to occur at every cell);
2) “Environmental selection” (a species can
occupy only a fixed portion of randomly distributed
“suitable localities”); and
3) “Endemicity” (most of species are restricted in
its potential distribution to a few regions).
To parameterize the models, several world-wide
datasets on ciliates, flagellates and harpacticoid
copepods were used. The local:regional and regional:global diversity ratios and percentage of
endemics were estimated by simulating the equaleffort sampling across the lattice, with varying the
full number of species (“actual diversity”) and
number of samplings per cell (“sampling effort”).
All parameters, predicted by every model, strongly
depended on the sampling effort but were only
slightly, if ever, influenced by the observed:actual
global diversity ratio. The predictions of the first
two models were generally close to each other, but
differed noticeably from those of the third one.
These results indicate that the above-mentioned
parameters are heavily influenced by undersampling.
Nevertheless, they can serve as informative characteristics in comparative biodiversity studies, even
if the true number of species can hardly be estimated
overall.
GLOBAL DIVERSITY AND DISTRIBUTION
OF MARINE BENTHIC HETEROTROPHIC
FLAGELLATES
Azovsky A.I.1, Tikhonenkov D.V.2,3
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environment, northern, eukaryotic, oilsandsassociated, microbial, alberto
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