University of California, Santa Barbara

Faculty Profile

Patricia Holden

Associate Professor

Mechanical Engineering
Marine Science

Patricia Holden


Donald Bren School of Environmental Science and Management
University of California
Santa Barbara, CA 93106

tel: (805) 893-3195
fax: (805) 893-7612

Personal web site

Research Description

Professor Holden studies the microbiology of engineered and natural systems. Two main environmental problems are currently being studied in the Holden lab: 1) bioavailability constraints on the biodegradation of non-aqueous phase liquid (NAPL) hydrocarbon pollutants in soil, and 2) distribution of pathogenic bacteria in coastal environments. Part of the Holden lab interest includes gaining a fundamental understanding of bacterial growth habits in unsaturated porous media such as soil and sand. Thus, Professor Holden and her students also study bacterial biofilms in unsaturated environments with an objective of knowing when and where they form in soil and how the extracellular polymers associated with biofilms affect pollutant bioavailability and biodegradation. Professor Holden, with colleagues in engineering, chemistry and materials, recently acquired an environmental scanning electron microscope (ESEM) for use in visualizing soft matter including bacterial biofilms.


Professor Holden is an environmental microbiologist appointed in the Bren School at UCSB with formal affiliations in Mechanical Engineering, Earth Science, and Ecology, Evolutionary and Marine Biology (EEMB) at UCSB. Holden's research regards the physiology and ecology of bacteria involved in pollutant biotransformations, coastal water health, interactions of engineered nanoparticles with bacterial cells, and soil processes.


  • Outstanding Graduate Student Instructor Award, University of California, Berkeley, 1995
  • Graduate Research Assistantship, Los Alamos National Lab, 1992-1994
  • Switzer Environmental Fellow, 1992
  • University of California Graduate Mentorship Award, 1990-1992
  • Rotary International Group Study Exchange to Nigeria, 1988

Selected Publications

  • Soil microorganisms in soil clean-up: how can we improve our understanding?, J. Environ. Qual., 26, 1997, 32-40, Holden, P.A. and M.K. Firestone
  • Toluene diffusion and reaction in unsaturated Pseudomonas putida biofilms, Biotechnol. & Bioengin, 56, 1997, 656-670, Holden, P.A., J.R. Hunt, and M.K. Firestone
  • Unsaturated zone gas-phase biodegradaton: the importance of water potential., 50th Purdue Industrial Waste Conference Proceedings, 1997, 113-127, Holden, P.A., M.K. Firestone, and J.R. Hunt.
  • Water stress effects on toluene biodegradation by Pseudomonoas putida, Biodegradation, 8, 1997, 143-151, Holden, P.A., L.J. Halverson, and M.K. Fireston
  • Coupling transport and biodegradation of VOCs in surface soils, Environmental Health Perspectives, Vol 103, Supplement 5, 1995, 75-78, Hunt, J.R., P.A. Holden, and M.K. Firestone.

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