|Discovery/isolation of new Archaea
Organisms found to thrive in extreme habitats such as the acid hot springs
of Yellowstone National Park are termed extremophiles. Other than lobed
spheres, culturable, aerobic high temperature low pH-adapted archaea, (pH
2-3; 70-90°C) or bacteria have so far proven difficult to isolate from
their native acid hot spring environment. To date there are no successful
isolations of aerobic rod shaped archaea or bacteria optimally growing
as thermoacidophiles, i.e. below pH 3 and from 70° C to 90°C, although
one organism, Thermofilum found deep in mud sediments in these same
habitats, grows anaerobically using molecules from other nearby organisms.
Most success to date has come from the Amphitheater Springs region in
Yellowstone National Park. Members of our laboratory group isolated three
different organisms from the main springs in this region. We have also
confirmed the presence of microbes in several other springs within Yellowstone
Park, using DAPI (DNA staining) and direct examination at the electron
microscopic level and X-ray microanalysis. Perhaps the advent of genome
sequencing, particularly the small subunit of ribosomal RNA (16S rRNA),
has been the most useful approach. This allows us to evaluate any new isolates
and determine if they merit continued investigation as an undiscovered
organism or if they have already been reported and described as a genus.
These sequences are the blueprints for selecting representatives of the
domains archaea and bacteria for further study. In association with two
other laboratories (one, a federal biotechnology facility) we have begun
genome sequencing of newly cultured organisms and comparison of their SSU
rRNA sequences using archaea specific and bacteria specific primers with
those from mesophilic, thermophilic and hyperthermophilic (>80°C) organisms.
This approach helps to provide fundamental insight into the status of an
isolate as a known or an undiscovered organism. Complementary physiological
and structural biology studies will undoubtedly yield a large amount of
new and exciting data at both the fundamental and applied level. We are
seeking students for this research.
Our first goal is to extend our sampling enrichments to include high
temperature sites such as Roaring mountain 77 to 90°C at pH 2.0, Great
Sulfur Spring (88°C; pH 2.0), Norris Annex (88°C; pH 2.0), and
Frying Pan Spring (88°C; pH 2.2). We expect to obtain unique new organisms
from these habitats. As part of this approach we are using 16S rRNA gene
sequence analyses (PCR based DNA fingerprinting) with archaea and bacteria-specific
primers to investigate the divesity of our mixed cultures. Analysis of
a lower temperature organism (55C; pH 3) revealed a clone that matched
with a high similarity (>99% over 1500 bp) to an uncultured, unknown bacterial
Our second goal is to evaluate the effects of nutritional supplements
on our current isolates and those obtained in the future. Here we will
use various supplements such as meat, yeast and cell extracts from our
thermophile cultures. Various combinations may increase our successes.
We will also use this approach to isolate and grow individual organisms
from our collections, both from dilutions and on solid medium.
Our third goal is to characterize the isolates, describe their physiological
and nutritional capabilities and to provide new generic descriptions of
any organisms we obtain. We already know that there are many undiscovered
organisms in the acid hot springs and we have obtained multiple aerobic
isolations. Because this work is already underway and we have cultures
presently growing, we believe these goals are realistic. We invite interested
students to participate in this research.
Representative publications :
Weiss Bizzoco, R. L., N. Banish, M. Lu, and S. Saavedra. 2000. New acidophilic
thermophilic microbes. Pages 117-128 in J. Seckbach,
editor, Journey to diverse microbial worlds.. Kluwer
Academic Publishers, Dordrecht, The Netherlands.
Lindstrom, R..F., R.F. Ramaley and R.W. Bizzoco 2002.
Invisible invasion: Potential contamination of Yellowstone
hot springs by human activity. Western North American
Weiss Bizzoco, R. L., Bass, R., Vuong, T. T., Vahl,
J. B., Hoang, C. L., Diaz, M. M. 2003. Selective adhesion
of extremophiles for scanning electron microscopy.
Journal of Microbiological Methods 55:787-790.
Ellis, D. G., Weiss Bizzoco, R. L., Maezato, Y., Baggett,
J.N., Kelley, S. T. (2005) Microbiological Examination
of Acidic Hot Springs of Waiotapu, North Island, New
Zealand. New Zealand Journal of Marine and Freshwater
Mathur, J., Bizzoco, R. W., Ellis, D. G., Lipson,
D. A., Poole, A. W., Levine, R., Kelley, S.T. 2007.
Effects of abiotic factors on phylogenetic diversity
of bacterial communities in acidic thermal springs.
Applied and Environmental Microbiology Applied and
Environmental Microbiology 73:2612-2623.
Ellis, D. G., Bizzoco, R. W. and Kelley, S.T. 2008.
Halophilic Archaea determined from geothermal steam
vent aerosols. Environmental Microbiology 10:1582-1590.
Benson, C.A., Bizzoco, R.W., Lipson, D.A., Kelley, S.T. (2011) Microbial diversity in nonsulfur, sulfur and iron geothermal steam vents. FEMS Microbiology Ecology 76:74-88.
Tin, S., Bizzoco, R.W., Kelley, S.T. (2011) Role of the terrestrial subsurface in shaping geothermal spring microbial communities. Environmental Microbiology Reports 3:491-499.
Benson, C.A., Bizzoco, R.W., Kelley, S.T. (2012) Microbial diversity in non-sulfur and iron geothermal steam vents. Yellowstone Science 20:5-6.
Tin, S., Bizzoco, R.W., Kelley, S.T. (2012) Role of the terrestrial subsurface in shaping geothermal spring microbial communities. Environmental Microbiology Reports 4: 1.
Papers in press
Weiss Bizzoco, R.L., Kelley, S.T. (2013) Microbial diversity in acidic high temperature steam vents. Polyextremophiles: 1-15. (in press).