Contact Information

Job Responsibilities

I teach in the School of Life Sciences. My teaching responsibilities include: Introductory Microbiology; Plants, Medicine and Technology; Plant Biotechnology; Research in Bacteriology and Independent Research

Research Interests

We currently have several ongoing projects, two on important food plants of New York State and fundamental projects on bacterial whole genome sequencing: bacterial genetic regulation; metagenomics (environmental genomics) and medicinal properties of honeybee hive glue (propolis) with a special emphasis on bacterial antipathogenic properties.   
We also completed whole genome sequencing projects on three plant-associated bacteria: one from grapevine crown gall tumorsphere, one from grapevine xylem fluids, and the third from stalk tissue of sugarcane.   
Some of our research projects share a common theme in pathogenic bacterial gene regulation.  This theme is a mechanism known as quorum sensing (QS) gene regulation and has been widely documented in many pathogenic, symbiotic and commensal host-associated Gram-negative bacteria. The three key players in QS gene regulation are luxI and luxR homologs and chemical signals, known as N-acyl-homoserine lactones (AHL) or quorum sensing signals, produced by LuxI. LuxR is a signal-dependent regulator that acts as a transcriptional activator or repressor of gene expression. In this system bacteria produce and secrete chemical signals into their surroundings. At a threshold concentration (which measures cell density and environmental porosity), the AHL will bind LuxR. This binding of the quorum-sensing signal (AHL) to its cognate regulatory protein (LuxR homolog) leads to the modulation of global gene expression. QS systems in bacteria have been shown to foster both pathogenic and symbiotic interactions with humans, marine animals and plants.
 
Our projects include:
 
1. Communication signaling in bacteria on grape plants. Many grape plant associated bacteria communicate by small chemical signals called quorum-sensing signals. One project focuses on the characterized of signaling chemicals produced by bacteria isolated from vineyard grape plants. Chromosome and plasmid-encoded N-acyl homoserine lactones produced by Agrobacterium vitis wildtype and mutants that differ in their interactions with grape and tobacco Engineering Bacterial Competitiveness and Persistence in the Phytosphere
 
2. The application of bacterial signaling molecules, known as quorum sensing signals, in the improvement of corn (maize) against a bacterial pathogen called Pantoea stewartii subsp. stewartii. This bacterial plant pathogen is responsible for Stewart’s wild disease on sweet corn and of leaf blight disease on dent (field) corn. This bacterial pathogen reduces the quantity and quality of sweet corn grown in New York State. Long- and Short-Chain Plant-Produced Bacterial N-Acyl-Homoserine Lactones Become Components of Phyllosphere, Rhizosphere, and Soil
 
3. Genetic regulation of the stringent response gene rsh and AHL signal generator gene (luxI homolog) in our recently characterized grape tumor-associated Novosphingobium sp. bacterium. Identification of an rsh Gene from a Novosphingobium sp. Necessary for Quorum-Sensing Signal Accumulation
 
4. Metagenomic analysis of a pristine forest soil genetic library for luxI homologs.
 
5. Effects of honeybee hive glue, also known as propolis, on QS regulation systems in Alpha-proteobacteria

Selected Publications

Gan, HM, McGroty, SE, Chew, TH, Chan, KG, Buckley, LJ, Savka, MA, Hudson, AO. (2012). Whole genome sequence of Enterobacter sp. SST3: An endophyte isolated from Jamaica sugarcane (Saccharum sp.) stalk tissue. Journal of Bacteriol (Accepted for publication).

Gan, HM, Chew, TH, Hudson, AO, Savka, MA. (2012). Genome sequence of Novosphingobium sp. Strain Rr02-17, a nopaline crown gall associated bacterium isolated from Vitis vinifera L. Grapevine.  Journal of Bacteriol. 194: 5137-5138.  http://jb.asm.org/content/194/18/5137.full.pdf+html?sid=6579b9cd-6ab0-441e-b256-ec9243e9af9a
 
Gan, HM, Chew, TH, Hudson, AO, Savka, MA. (2012). Genome sequence of Methylobacterium sp. Strain GXF4, a xylem associated bacterium isolated from Vitis vinifera L. Grapevine.  Journal of Bacteriol. 194: 5157-5158.  http://jb.asm.org/content/194/18/5157.full.pdf+html?sid=6579b9cd-6ab0-441e-b256-ec9243e9af9a
 
György Dénes Bisztray, Edwin L. Civerolo, Terézia Dula, Mária Kölber, János Lázár, Laura Mugnai, Ernõ Szegedi, and Michael A. Savka. 2011. Grapevine pathogens spreading with propagating plant stock: detection and methods for elimination. In: Grapevines: Varieties, Cultivation…; Chapter 1, pages 1-88; PV Szabo & J Shojania, Editors; Nova Science Publishers, Inc. ISBN: 978-1-62100-361-8.
 
Bulman Z*, Le P, Hudson AO, and Savka MA. 2011. A novel property of propolis (bee glue): anti-pathogenic activity by inhibition of N-acyl-homoserine lactone mediated signaling in bacteria. Journal of Ethnopharmacology 138:788-797.
http://www.sciencedirect.com/science/article/pii/S0378874111007689
 
Gan HM*, Bulman Z*, Hudson AO, Azmeer MA*, Shattuck E*, and Savka MA. 2011. Methylobacterium sp. GFX4 16s ribosomal RNA gene sequence. Locus JN002163; 1476 bps DNA. NCBI GenBank. http://www.ncbi.nlm.nih.gov/guide/dna-rna/
 
Savka MA and Hudson AO. 2011. Bioluminescence biosensor strains for the detection of quorum-sensing N-acyl-homoserine lactone signal molecules. In: Bioluminescence, pages 49-70; DJ Rodgerson, Editor; Nova Science Publishers, Inc. ISBN: 978-1-61209-747-3.
 
 
Hudson AO, Ahmad NH*, Van Buren R* and Savka MA. 2010. Sugarcane and Grapevine Endophytic Bacteria: Isolation, Detection of Quorum Sensing Signals and Identification by 16S v3 rDNA Sequence Analysis. In: Current Research, Technology and Education Topics in Applied Microbiology and Microbial Biotechnology, Antonio Mendez Vilas, Editor, December, pages 801-806.
 
Savka MA, Le TP and Burr JT. 2010. LasR receptor for detection of long-chain quorum-sensing signals: Identification of N-acyl-homoserine lactones encoded by the avsI locus of Agrobacterium vitis. Current Microbiology, EPub. Ahead of print, June 1, 2010. Curr Microbiol (2011) 62:101–110. DOI 10.1007/s00284-010-9679-1
 
Lowe N*, Gan HM*, Chakravartty V*, Scott R*, Szegedi E, Burr T and Savka MA. 2009. Quorum-sensing signal production by Agrobacterium vitis strains and their tumor-inducing and tartrate-catabolic plasmids. FEMS Microbiol Lett 296:102-109.
 
Gan, HM*, Buckley L, Szegedi, E, Hudson, AO and Savka, MA. 2009. Identification of an rsh gene from a Novosphingobium sp. necessary for quorum-sensing signal accumulation. Journal of Bacteriology 191(8):2551-2560.
 
Gan HM*, and Savka MA. 2008. Novosphingobium sp. Rr 2-17 Rsh (rsh) gene, complete. August 5; National Center for Biotechnology Information. Locus: EU984514.1.
 
Gan HM*, and Savka MA. 2008. Novosphingobium sp. Rr 2-17 16S ribosomal RNA gene. August 5; National Center for Biotechnology Information. Locus: EU984513.
 
Li Y, Gronquist MR, Hao G, Holden MR, Eberhard A, Scott R*, Savka MA, Szegedi E, Sule S and Burr TJ. 2006. Chromosome and plasmid-encoded N-acyl homoserine lactones produced by Agrobacterium vitis wildtype and mutants that differ in their interactions with grape and tobacco. Physiological and Molecular Plant Pathology 67:284-290.
 
Scott R*, Weil J*, Le PT, Williams P, Fray RG, von Bodman S and Savka MA. 2006. Plant-produced bacterial N-acyl-homoserine lactones become components of phyllosphere, rhizosphere and soil. Molecular Plant-Microbe Interactions 19(3):227-239.
 
Savka MA, Oger P, Dessaux Y , Rossbach S. 2002. Engineered bacterial competitiveness and persistence in the phytosphere. Molecular Plant-Microbe Interactions 15(9):866-874.
 
Savka MA, Shu-Yi Wang*, Wilson M. 2002. How to produce and characterize transgenic plants. American Biology Teacher 64(4):286-299.
 
Savka MA, Black RC, Binns AN. 2001. Tobacco etch virus leader sequence enhances inducible indole-3-acetic acid-lysine synthetase activity in transgenic plants. Plant Physiology and Biochemistry 39:631-641.
 
Savka MA and Binns AN. 2000. Introduction of DNA into plants. Pages 159-192. In: Gene Transfer Methods: Introduction of Genes into Living Cells and Organisms. Norton, PA and Steel, LF (eds.) BioTechniques Books. Eaton Publishing, Natick, MA, 272 pp. (ISBN 1-881299-34-1).
 
Jones AM, Im, K-H, Savka MA, Wu M-J, Dewitt NG, Shillito R, Binns AN. 1998. Auxin-dependent cell expansion mediated by overexpressed auxin binding protein 1. Science 282:1114-1117.
 
Zhang D, Shelby R, Savka MA, Dessaux Y, Wilson M. 1998. Separation, detection and quantification of imine-linked opines in plant tissues by high performance liquid chromatography. Journal of Chromatography A 813:247-253.
 
Savka MA and Farrand SK. 1997. Modification of Rhizobacterial Population by Engineering Bacterium Utilization of a Novel Plant-Produced Resource. Nature Biotechnology 15:363-368. Also noted in: This Month in Nature Biotechnology 1997. Specific plant-microbe interactions Nature Biotechnology 15:305.
 
Savka MA, Black RC, Binns AN, Farrand SK. 1996. Translocation and exudation of tumor metabolites in crown galled plants. Molecular Plant-Microbe Interactions 9:310-313.
 
Wilson M, Savka MA, Hwang I, Farrand SK, Lindow SE. 1995. Enhanced epiphytic colonization by an engineered mannityl opine-catabolizing Pseudomonas syringae strain on transformed mannityl opine-producing tobacco plants. Applied and Environmental Microbiology 61:2151-2158.
 
Farrand SK, Wilson M, Lindow SE, Savka MA. 1994. Modulating colonization by plant-associated microbes. In: M. H. Ryder, P. M. Stevens, and G. D. Bowen (eds.). Improving Plant Productivity with Rhizosphere Bacteria. CSIRO, Australia. pp. 233-237.
 
Savka MA, Liu L, Farrand SK, Berg RH, Dawson JO. 1992. Induction of hairy roots or pseudoactinorhizae on Alnus glutinosa, A. acuminata and Elaeagnus angustifolia by Agrobacterium rhizogenes. Acta Œcologica 13:423-431.
 
Savka MA and Farrand SK. 1992. Mannityl opine accumulation and exudation by transgenic tobacco. Plant Physiology 98:784-789. Berg RH, Lui L, Dawson JO, Savka MA, Farrand SK. 1992. Induction of pseudoactinorhizae by the plant pathogen Agrobacterium rhizogenes. Plant Physiology 98:777-779.
 
Savka MA, Ravillion B, Noel GR, Farrand SK. 1990. Induction of hairy roots on cultivated soybean genotypes and their use to propagate the soybean cyst nematode. Phytopathology 80:503-508.
 
Savka MA, Dawson JO, Jokela JJ, Skirvin RM. 1987. A liquid culture method for rescuing immature embryos of eastern cottonwood. Plant Cell, Tissue and OrganCulture 10:221-226.
 
Savka MA, Jokela JJ, Skirvin RM, Dawson JO. 1985. Action of 6-benzylaminopurine and indole-3-butyric acid on development of immature embryos of Populus deltoides Bartr. In:Fourth North Central Tree Improvement Assoc. Meeting., August 12-15, Daniel E. Keathley (ed.). Dept. Forestry, Michigan State Univ., East Lansing, MI, pp. 140-148.
 
Jokela JJ and Savka MA. 1985. Performance of range-wide seed sources of Northern white cedar in three central Illinois plantations over a 20 year period. In: Fourth North Central Tree Improvement Assoc. Meeting, August 12-15, Daniel E. Keathley (ed.). Dept. Forestry, Michigan State Univ., East Lansing, MI, pp. 107-111.
 
Savka MA, Skirvin RM, Jokela JJ, Dawson JO. 1985. Culture of ovules containing immature embryos of eastern cottonwood in vitro. In: Proc. Fifth Central Hardwood Conf., April, 15-17, J. O. Dawson and K. A. Majerus (eds.). Dept. Forestry, Univ. of Illinois at Urbana-Champaign, pp. 234-238.
 
* Denotes Undergraduate Student