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Mary Ann
Bruns
Asst. Prof. of Soil Science/Microbial
Ecology
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Responsibilities:
Soil microbiological analysis; characterization of microbial
populations and communities in the soil and rhizosphere;
application of molecular biology methods to soil microbial
ecology.
Research
Interests: Comparative microbial ecology of terrestrial
systems; microorganisms involved in nitrogen cycling and retention;
microbial ecology-based approaches to reducing nutrient losses from
agriculture and forestry; DNA fingerprinting to track composition
of microbial communities in soils and rhizospheres.
- Ph.D. Crop & Soil
Sciences, Michigan State University, 1996
- M.A. Urban &
Regional Planning, Environmental Sector, Univ. of Iowa,
1988
- M.S. Food Science &
Technology, Univ. of Nebraska, 1978
- B.A. Microbiology,
Univ. of Nebraska, 1974
CURRENT PROJECTS AND PLANNED COLLABORATIONS:
- Microbial hydrogen
production (with Dr. Prabha Iyer,
postdoctoral associate, Dr. Bruce Logan, Civil and Environmental
Engineering, and BRIE graduate student Husen Zhang)
- Microbial processes and
populations in naturally metalliferous soils (with Carolina Yanez,
Dr. Carmen Enid Martinez, Soil
Science, and BRIE Summer Undergraduate Fellow Krys
Hamlett)
- Soil aggregate
development and microorganisms (with Soils graduate student
Jody Gibson and Dr. Henry Lin, Soil Science)
- Land management effects
on soil microarthopod abundance and diversity (with Ecology
graduate student Loren Byrne and
Dr. K.C. Kim, Entomology)
- Microbial deodorization
of livestock wastes (with Ecology graduate students Hugo Castillo and Masami Tonegawa, undergraduate
student Erica Petre, Dr. Eileen Wheeler, Agricultural and
Biological Engineering, and Dr. Jerzy Dec, Penn State Institutes of
the Environment
- Molecular
characterization of microbial mat communities (with Dr. Kate
Freeman, Geosciences, and BRIE graduate student Courtney
Turich)
- Impacts of biosolids on
soil microbial communities in mine soils (with Rick Stehouwer, Soil Science.
- Characterization of
perchlorate-reducing bacteria in engineered treatment systems (with
BRIE graduate student Husen Zhang and Dr. Bruce Logan, Civil &
Environ Engineering.
- Bacterial
solubilization of phosphorus-containing minerals (with Soil
graduate student Ann Widrig and
Dr. Carmen Enid Martinez, Soil
Science)
- Management effects on
soil organic matter and microbial communities (with Dr. Doug Archibald and Dr. Heather Karsten, Crop Science, Dr. Mary
Barbercheck, Entomology, Agroecosystem Science major Amber
Lockawich, and Biology undergraduate student Summer
Holmes.)
SOIL MICROBIAL ECOLOGY LABORATORY
A single gram of
agricultural topsoil may contain at least one billion bacteria, a
hundred thousand fungi, and thousands of protozoans and other
microscopic organisms! Our ability to study such incredibly diverse
microbial assemblages is hampered by the fact that most of these
microorganisms will not grow under laboratory conditions. To get
around this problem, M.A. Bruns's soil microbial ecology lab
employs DNA fingerprinting of bacterial and eukaryotic communities
to learn more about the key microorganisms involved in soil
nutrient cycling and other important environmental processes. Basic
steps involved in DNA fingerprinting are 1) extracting microbial
DNA from soil; 2) polymerase chain reaction (PCR) amplification of
ribosomal RNA genes; 3) separation of the PCR products by gel
electrophoresis; and 4) computer-assisted analysis of the
"fingerprints," or DNA band patterns produced in the gels. If we
want to know more about the microbial populations that produce
specific bands, we can cut these bands out of the gels, obtain
their DNA sequence(s), and use the sequences for preliminary
identification. We are interested in learning how soil microbial
communities change over time when they are subjected to different
environmental conditions and management treatments. We want to
learn how to work with (not against!) the beneficial microorganisms
that cleanse and improve our environment.
- Hugo
Castillo
- Krys
Hamlett
- Ann Widrig
- Dr. Prabha
Iyer
- Carolina
Yanez
- Erica Petre
- Dr. Carmen Enid
Martinez
- Jody Gibson
- Dr. Mary Ann
Bruns
- Amber
Lockawich
- Husen Zhang
- Loren Byrne
PARTICIPATION IN OTHER PROGRAMS AT PENN STATE
Huck Institute of Life
Sciences (co-funder)
BRIE, Biogeochemical Research Initiative for Education
Intercollege Graduate Degree Program in Ecology (IGDPE)
Penn State Institutes of the Environment (PSIE)
WISER (Women in Science and Engineering Research)
MURE (Minority Undergraduate Research Experience)
H2E Center (Hydrogen Helping the Environment)
- Soil Microbial Ecology
Postdoctoral Researcher, Laboratory of Dr. Kate Scow, Dept. of
Land, Air, and Water Resources, University of California, Davis,
1996-1999
- Congressional Fellow
& Analyst, Food and Renewable Resources Program, Office of
Technology Assessment, U.S. Congress, Washington, DC,
1988-90.
- Microbiologist,
Schwan's Sales Enterprises, Salina, KS, 1982-85.
- U.S. Peace Corps
Volunteer and Volunteer Leader, Cameroon, 1979-82.
- 1. Zhang, H, MA Bruns,
and BE Logan. 2002. Perchlorate reduction by a novel
chemolithoautotropic, hydrogen-oxidizing bacterium. Environmental
Microbiology 4:570-576.
- Bruns MA, JR Hanson, J
Mefford, and KM Scow. 2001. Isolate PM1 populations are dominant
and novel methyl tert-butyl ether-degrading bacteria in compost
biofilter enrichments. Environmental Microbiology
3:220-225.
- Bruns MA, and DH
Buckley. 2002. Isolation and purification of microbial community
nucleic acids from environmental samples, pp 564-572. In C.J. Hurst
(ed.), Manual of Environmental Microbiology, 2nd ed.,
ASM Press, Washington, DC.
- M.A. Bruns and K.M.
Scow. 1999. DNA fingerprinting as a means to identify sources of
soil-derived dust: problems and potential. In Integrated Assessment
of Ecosystem Health. G. Fogg et al. (eds.), CRC Press, Boca Raton,
FL.
- M.A. Bruns, J.R.
Stephen, G.A. Kowalchuk, J.I. Prosser, and E.A. Paul. 1999.
Comparative diversity of ammonia oxidizer 16S rRNA gene sequences
in native, tilled and successional soils. Applied and Environmental
Microbiology 65:2994-3000.
- M.A. Bruns, M.R. Fries,
J.M. Tiedje, and E.A. Paul 1998. Functional gene hybridization
patterns of terrestrial ammonia-oxidizing bacteria. Microbial
Ecology 36:293-302.
- Song XH, Hopke PK,
Bruns MA, Graham K, and Scow KM. 1999. Pattern recognition of soil
samples based on the microbial fatty acid contents. Environ. Sci.
Technol. 33:3524-3530.
- Stephen, J. R., G. A.
Kowalchuk, M.A. Bruns, J.I. Prosser, T.M. Embley, and J.
Woldendorp. 1998. Analysis of ß-subgroup chemolithotrophic
ammonia oxidizer populations by DGGE, membrane transfer and
hierarchical 16S rDNA oligonucleotide probing. Appl. Environ.
Microbiol. 64:2958-2965.
- Zhou J, Bruns MA, and
Tiedje JM (1996) Rapid method for recovery of DNA from soils of
diverse composition. Appl. Environ. Microbiol.
62:316-322.
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