Dr David Ryan

BSc, MSc, PhD

Assistant Registrar
Head of Department of Science and Health 2003 - 2014
Member of EnviroCORE at IT Carlow

e: david.ryan@itcarlow.ie t: 059 9175709

  • Research Interests
  • Publications
  • Research Supervision

Research Experience

  • Postdoctoral researcher with Dr. David Dowling on FP4 and FP5 European projects “Endegrade” and GM-Rhizoremediation”
  • PhD. with Professor Emer Colleran at the Environmental Research Institute at the National University of Ireland, Galway
  • MSc. in Innovation Management in the Public Service jointly awarded by Letterkenny Institute of Technology and the University of Ulster
  • BSc. in Biotechnology in the Department of Biochemistry at the National University of Ireland, Galway

Research Interests

Dr. David Ryan is a graduate of the National University of Ireland in Galway where he completed his undergraduate studies in biotechnology in the department of biochemistry.  His PhD. in the environmental research unit at NUIG, under the supervision of Professor Emer Colleran, focused on microbial plasmid based metal resistance systems.  Dr. Ryan’s research interests include the identification of new genes and pathways for microbial metal resistance, bioremediation and plant growth promotion and their application in developing enhanced phytoremediation and phytoprotection systems through the use of endophytic and rhizospheric microbial inoculation of biofuel crops. 

He has also worked on the development of microbial biosensors to detect both contamination and degradation of target compounds, was involved with a TSR Strand III project which saw the establishment of an Agribiotics research unit at ITC examining phytotechnologies for biofuel and bioenergy crops, hosted an IRC funded postdoctoral research project examining strategies for the acceleration and assessment of the decomposition of biodegradable municipal waste and is involved with an SFI funded TIDA grant for research into the development of a smart BioSwale system for treatment of wastewater. 

Dr. Ryan is based at the EnviroCORE research unit at IT Carlow, is co-author on 24 peer-reviewed journal publications and book chapters and approximately seventy abstracts and conference proceedings.  His research has resulted in the formation of a spin out campus-company at ITC, MicroGen biotech, with a focus on soil bioremediation.  

Research projects to date:

Analysis of soil bioremediation potential of isolates from Shandong, China.  Dr. Xuemei Liu (MicroGen), Dr. Kieran Germaine (ITC), Dr. David Dowling (ITC), Ms. Esther Simone Voncente (Leonardo Dv Vinci) – ongoing research

In-situ bioremediation and molecular microbiological monitoring of ammonia contamination in shallow groundwater.  Evelyn Joyce and Dr. Nabla Kennedy (WIT) – ongoing research

Bioremediation of tributyltin (TBT) in Irish marine sediments – microbial screening and process optimisation.  Christopher Finnegan and Dr. Guiomar Garcia Cabellos (ITC) – ongoing research

Microbial interactions of the novel bacterium Ensifer aherans OV14 with economically important crops.  Aisling Dunne, Dr. Ann Marie Enright (ITC) and Dr. Ewen Mullins (Teagasc) – ongoing research

Development of endophyte and rhizosphere enhanced Plant Growth Promotion (PGPR) and phytoremediation systems – colonisation dynamics, mechanisms and impacts, Nicholas Otieno, ongoing research

Examination of plant growth promoting bacteria on plant yield and their effect as bio-insecticides, Richard Lally, ongoing research

Developing strategies for acceleration of biostabilisation of Biodegradable Municipal Waste (BMW), Dr. Nabla Kennedy, 2013 

Developing improved phytoremediation and phytoprotection systems, Olivia Odhiambo, PhD., 2011

Characterisation of tributyltin resistant microbes isolated from Irish coastal regions, Karen Browne, MSc., 2011

The isolation and characterisation of bacterial endophytes and their potential applications for improving phytoremediation, Elaine Keogh, PhD, 2009

Evaluating microbial biosensors to detect polychlorinated biphenyl (PCB) contamination and degradation in a range of environments and conditions, Monica Dempsey, MSc., 2009

Development and application of biosensor technologies for the biodegradation of environmental pollutants, Xuemei Liu, PhD., 2008

Construction of endophytic xenobiotic degrader bacteria for improving the phytoremediation of organic pollutants, Kieran Germaine, PhD., 2007

The monitoring of a prokaryotic bioremediation system in PCB contaminated soil and their in-situ quantification, Jill Hogan, PhD 2006

The generation and molecular analysis of multiresistant microbial strains and associated operons for the bioremediation of toxic metals, Robert Ryan, PhD, 2005

The genetic analysis of the ars operon of the multi-resistant Inc HI2 plasmid, R478, David Ryan, PhD., 1999



Ryan R.P, Ryan, D. and Dowling D. (2008). Heavy metal tolerant rhizobacteria and their phytoremediation potential. In: Phytoremediation and Rhizoremediation: Focus on Biotechnology. Vol 9B. Edited by Mackova M, Dowling DN, Macek T. Springer.

Garcia-Cabellos, G., Byrne, M., Stenberg, M., Germaine, K., Brazil, D., Keohane, J., Ryan, D. and Dowling, D. (2005) A small scale constructed wetland to treat different types of wastewaters. In: Nutrient Management in Agricultural Watersheds: A Wetlands Solution, pp224-229 edited by E. J. Dunne, K.R., Reddy and O.T. Carton. Wageningen Academic Publishers, The Netherlands.

Finnegan, C., Garcia-Cabellos, G., Enright, AM and Ryan, D (in preparation) The ability of a range of microbial species to degrade TBT into its less toxic species monobutyltin (MBT) and dibutyltin (DBT)

Xuemei Liu, X., Kiwanuka, S., Ryan, D., Dowling D., and Germaine, K. ‘Use of Ecopiling in a Field Trial to Remediate Heavily Impacted Creosote Contaminated Sediment and Soil Submitted to the Journal of Environmental pollution in January 2015

Germaine, K., Byrne, J., Liu, X., Keohane, J., Culhane, J., Lally, R., Kiwanuka, S., Ryan, D. and Dowling, D.N. (2015) ‘Ecopiling: a combined phytoremediation and passive biopiling system for remediating hydrocarbon impacted soils at field scale’ Frontiers in plant science 5 (756) 1-6

Lally, R., Moreira, A.S., Galbally, P., Ryan, D., Germaine, K., and Dowling, D.N (2013) Application of Endophytic Bacteria Possessing Plant Growth Promoting Traits for the Use in Bioenergy Crop Brassica napus  Aspects of Applied Biology 120: 9-13

Otieno, N., Culhane, J., Germaine, K., Brazil, D., Ryan, D., and Dowling D.N. (2013) Screening of large collections of plant associated bacteria for effective plant growth promotion and colonisation.  Aspects of Applied Biology 120: 23-28

Power, B, Liu, X., Germaine, K., Ryan, D., Brazil D and D. N. Dowling (2011). Alginate beads as a storage, delivery and containment system for genetically modified PCB degrader and PCB biosensor derivatives of Pseudomonas fluorescens F113. Journal of Applied Microbiology. 110(5):1351-8.

Liu, X., Germaine, K.J., Ryan, D. and Dowling, D.N. (2010). Modified Pseudomonas biosensing biodegraders to detect PCB and chlorobenzoate bioavailability and biodegradation in contaminated soils. Bioengineered Bugs 1:3, 1-9.

Liu, X., Germaine, K.J., Ryan, D. and Dowling, D.N. (2010).  Whole cell fluorescent biosensors for bioavailability and biodegradation of polychlorinated biphenyls. Sensors 10: 1377-1398


Germaine K.J., Keogh E., Ryan, D. and Dowling, D.N. (2009). Bacterial endophyte-mediated naphthalene phytoprotection and phytoremediation. FEMS Microbiol. Lett. 2009, 296, 226-234.


Ryan, R.P., Germaine, K., Franks, A., Ryan, D.J. and Dowling, D.N. (2008).  Bacterial endophytes: recent developments and applications. FEMS Microbiol. Lett.  278:1-9


Ryan, R. P., Ryan, D. and Dowling, D. (2007).  Plant protection by the recombinant, root-colonising Pseudomonas fluorescens F113rifPCB strain expressing arsenic resistance: improving rhizoremediation Letters in Applied Microbiology 45: 668-674


Ryan, R. P, Ryan, D., Sun, YC., Li, FM., Wang, Y. and Dowling, D. (2007).  An acquired efflux system is responsible for copper resistance in Xanthomonas strain IG-8 isolated from China FEMS Microbiol Lett. 268: 40-6.


Liu, X., Germaine, KJ., Ryan, D. and Dowling, DN .(2007)  Development of a GFP-based biosensor for detecting the bioavailability and biodegradation of polychlorinated biphenyls (PCBs). (JEELM) Journal of Environmental Engineering and Landscape Management 15:261-268.


Germaine, K.J, Liu, X., Garcia-Cabellos, G., Hogan, J.P., Ryan, D. and Dowling, D.N. (2006).   Bacterial endophyte- enhanced phytoremediation of the organochlorine herbicide 2,4-dichlorophenoxyacetic acid. FEMS Microbiology Ecology 57: 302-310.


Gilmartin, N., Ryan, D. and Dowling, D.N (2005).  Analysis of the C-terminal domain of Burkholderia sp. strain LB400 BphK reveals a conserved motif that affects catalytic activity. FEMS Microbiology Letters 249: 23-30.


Ryan, R.P., Ryan, D. and Dowling, D.N. (2005).   Multiple metal resistant transferable phenotypes in bacteria as indicators of soil contamination with heavy metals. Journal of Soils & Sediments 5:95-100.


Germaine, K, Garcia-Cabellos, G., Borremans B., van der Lelie, N., Barak, T., Oeyen, L., Vangronsveld, J., Porteous-Moore, F., Moore, E., Campbell, C., Ryan, D. and Dowling D. (2004).  Colonisation of Poplar trees by gfp expressing bacterial endophytes FEMS Microbial Ecology 48: 109-118


Hogan, J; Sherlock, O; Ryan, D; Whelan, C; Francesconi, S., Rivilla, R. and Dowling, D.  (2004).  Fluorescence resonance energy transfer (FRET) based molecular detection of a genetically modified PCB degrader in soil.  FEMS Microbiology Letters 236:349-357


Ryan R. P, Ryan D., Dowling D. (2004).  “The isolation and characterisation of a multiple heavy metal resistant plasmid pITCRR46 from a heavy metal contaminated site” In: The BioNet Conference ISSN publication.


Gilmartin, Niamh., Ryan, D., Sherlock, O., and Dowling, D., (2003).  A potential role for the bphk gene encoding a Glutathione S-transferase in the PCB breakdown pathway” FEMS Microbial Letters.


Gilmartin, N., Ryan, D., Sherlock, O. and Dowling, D. (2003).  BphK shows dechlorination activity against 4-chlorobenzoate, an end product of bph-promoted degradation of PCBs. FEMS Microbiology Letters 222:251-255.


Ryan, D. and Colleran, E. Arsenical resistance in the IncHI2 plasmids (2002).  Plasmid, 47, 234-240


Conference Presentations:


Approximately 70 to date