Center for Biofilm Engineering News Update:  May, 2002 Volume 5, Issue 5   __________________________________________   Research Highlights   Paper Spotlight   Internal and External Mass Transfer in Biofilms Grown at Various Flow Velocities   This paper discusses the response of biofilm structure to the flow velocity. It appears that biofilms arrange their internal structure according to the flow velocity at which they are grown, which affects the internal mass transfer rate and microbial activity. In biofilms grown at various flow velocities, we determined the vertical profiles of the local relative effective diffusivity (termed Dl) at several locations within each biofilm. From these profiles we calculated the surface-averaged relative effective diffusivity (termed Dsa) at various distances from the bottom and plotted it against these distances. The Dsa decreased linearly toward the bottom, forming well-defined profiles that were different for each biofilm. The gradients of these profiles were multiplied by the diffusivity of oxygen, z=Dw dD/dz, and plotted versus the flow velocity at which each biofilm was grown. The gradients were low at flow velocities below 10 cm/s, reaching a maximum at a flow velocity of 10 cm/s, and decreasing again at flow velocities exceeding 10 cm/s. The existence of a maximum indicates a possibility that two opposing forces were affecting the slope of the profiles. To explain these observations we hypothesized that biofilms, depending on the flow velocity at which they are grown, arrange their internal architecture to control (1) the nutrient transport rate and (2) the mechanical pliability needed to resist the shear stress of the water flowing past them. It appears that biofilms attempt to satisfy the second goal first, to increase their mechanical strength, and that they do so at the expense of the nutrient transfer rate to deeper layers. This increase in mechanical strength is associated with an increase in biofilm density, which slows down the internal mass transport rate. Biofilms grown at low flow velocities exhibit low density and high effective diffusivity, but cannot resist higher shear stress, while biofilms grown at higher flow velocities are denser and can resist higher shear stress, but have a lower effective diffusivity.   Beyenal, H. and Z. Lewandowski, "Internal and External Mass Transfer in Biofilms Grown at Various Flow Velocities," Biotechnol. Prog. 18:55-61 (2002).   _________________________________________   Biofilm Art   Bioglyphs: A Living Collaboration with Bioluminescent Organisms   Bioglyphs was a biofilm art exhibit co-created by the MSU School of Art, the CBE, and billions of bioluminescent organisms. It was such a success that we have dedicated a web page to tell you all about it. From this web page, you can read the exhibit brochure designed and written by Peg Dirckx, view the photos, and read the local press releases.   http://www.erc.montana.edu/Res-Lib99-SW/newsarchives/HTML/2002/bioglyphs.htm   _________________________________________   Awards and Honors   Faculty Travel Award   Dr. Jeff Leid received a Biomedical Research Infrastructure Network (BRIN) Faculty Travel award of $4,000. This award will allow Dr. Leid and Dr. Mark Shirtliff an opportunity to spend a week at the University of Oklahoma learning about a new animal model to study biofilm infections of the eye. The Montana Network for Biomedical Research Opportunities program sponsors the award. Dr. Leid is the CBE's Immunology Projects Director and he is also an Assistant Research Professor in the Department of Cell Biology and Neuroscience at Montana State University. _______   AIChE Fellow   Dr. John Sears was named a Fellow of the American Institute of Chemical Engineers (AIChE) in the April 2002 issue of Chemical Engineering Progress. Seven new fellows were initiated this year.   _________________________________________   Visitors   Dr. Lynne McLandsborough, an associate professor from the Department of Food Science at the University of Massachusetts Amherst, is on a three-month sabbatical at the CBE, April through June. She is working with Dr. Phil Stewart's Biofilm Control research group to study the susceptibility of Listeria monocytogenes biofilms to chlorine. L. monocytogenes is a gram-positive organism that is widely distributed in the environment and is associated with plant material, alive or dead, water and soil. Although listeriosis is a rare food-borne disease, the presence of this organism is responsible for over 60% of all U.S. Food and Drug Administration class I recalls.   Dr. McLandsborough’s group started biofilm research in the past two years and their first publication in this area, entitled “Microtiter plate assay for assessment of Listeria monocytogenes biofilm formation,“ will be in the June issue of Applied and Environmental Microbiology. In this paper, biofilm formation of L. monocytogenes strains, previously separated into molecular lineages, was studied. Strains that fall within lineage I include all food-borne epidemic strains as well as isolates from sporadic cases of human and animal listeriosis. Lineage II strains include isolates from sporadic cases of human and animal listeriosis and lineage III strains are all associated with animal disease. In the conditions tested in this study, they found that lineage I strains had significantly higher levels on microtiter plate surfaces than lineage II and lineage III strains. This difference may be due to specific genes or lineage-specific allelic variations that may contribute to biofilm growth. Their hypothesis is that the relatively greater biofilm production of lineage I strains may be one factor contributing to prevalence of this lineage in human disease.   Ongoing projects in her Amherst laboratory include: studying the genetics of L. monocytogenes biofilm formation, monitoring and studying the diversity of organisms living within seafood-processing environmental biofilms containing L. monocytogenes, and growth of E. coli O157:H7 at oil/liquid and liquid/solid inter-phases.   _______   Amandine Bugnicourt is a biotechnology student from the Institut National des Sciences Appliquees de Lyon, France, where she completed her coursework before coming to the CBE to carry out a practical internship required of her degree. She will be at the CBE through early August, working in the Biofilm Control lab.     _________________________________________   International Collaborative Workshops   Subsurface Bioremediation   Dr. Al Cunningham taught a short course with Dr. Rainer Helmig, Institute fur Wasserbau, Stuttgart, Germany. The short course, "Multiphase flow, transport and bioremediation in the subsurface," was taught at the University of Stuttgart for the International Association of Hydraulic Engineering and Research, March 11-14, 2002. The short course was attended by 25 graduate students from northern Europe.   http://www.iws.uni-stuttgart.de/Weiterbildung/kurse/index_03_2002.html   _______   Biofilm Methods   Drs. Michael Givskov, Søren Molin and Bill Costerton organized a Biofilm Method Workshop, - A PhD Course, BioCentrum, Technical University of Denmark, Copenhagen, April 1-6, 2002. Presenters from the CBE were Bill Costerton, Jeff Leid, Paul Stoodley, and Paul Sturman. This workshop was made possible by an NSF Partnerships in Education and Research (PER) grant awarded to the CBE. For more details about the grant and to view the workshop agenda, see http://www.erc.montana.edu/Res-Lib99-SW/Workshops/PER/default.htm   _______   Efficacy Testing and Assessment of Biocidal Products   Drs. Bill Costerton and Marty Hamilton were presenters at the 1st OECD Efficacy Workshop on Certain Antimicrobial Biocides, in Arlington, Virginia, USA, April 22-24, 2002. The workshop was organized by the Organisation for Economic Co-operation and Development (OECD), Paris, France, and hosted by the USA Environmental Protection Agency (EPA). Future workshops are planned throughout OECD membership countries. The goal of these workshops is to develop international guidance for efficacy testing and assessment of biocidal products, thereby achieving better global protection for health and the environment.   Invited speakers addressed the plenary session topic, Emerging Science Issues. Dr. Michael Doyle, USA, presented "The Role of Antimicrobials in Controlling Food Pathogens," Dr. William Costerton, USA, presented "Introduction to Biofilms," Dr. Hans-Curt Flemming, Germany, presented "Extracellular Polymeric Substances: The House of Biofilm Cells," and Dr. Marty Hamilton, USA, presented "Performance Standards."   For more information about the OECD, visit their web site at http://www.oecd.org/ehs/   _________________________________________   Upcoming CBE Workshops and Meetings     Research Experience for Undergraduates Workshop Introduction to Biofilms June 4-5, 2002 Montana State University   _______   Industrial Associate Conference and TAC Meeting July 23-25, 2002 Montana State University _______   Biofilm Image Analysis Workshop July 25-26, 2002 Center for Biofilm Engineering Montana State University Bozeman, MT, U.S.A Daily workshop activities will include lectures and laboratory sessions. The lectures will cover biofilm structure and image analysis of biofilms. The lab sessions will cover how to acquire biofilm images and how to use the biofilm image analysis software developed by the Biofilm Structure and Function Research Group. Workshop details and registration forms can be found at: http://www.erc.montana.edu/CBEssentials-SW/research/Structure_function/default.htm _______   Microsensors: Manufacture and Applications Workshop August 19-23, 2002 Center for Biofilm Engineering Montana State University Bozeman, MT, U.S.A Microsensors (pH, dissolved oxygen, ion selective microelectrodes) are becoming indispensable tools for studying biofilms and small biological samples. The goal of this workshop is to provide the participants with the knowledge necessary to design, manufacture, and apply such microsensors. Lab sessions and lectures will illustrate the electrochemical principles of the measurements, explain how microsensors are manufactured, and demonstrate how they are applied to study biofilms.  The workshop is sponsored by the Biofilm Structure and Function Research Group at the Center for Biofilm Engineering, Montana State University. The activities include four days of lectures and lab sessions, and a one-day field trip to Yellowstone National Park.  For details on this workshop see the following web address. http://www.erc.montana.edu/CBEssentials-SW/research/Structure_function/default.htm See the Events Calendar for more conference and workshop information at http://www.erc.montana.edu/CBEssentials-SW/whats_new/index.htm   __________________________________________   CBE People in Action   Dr. Al Cunningham presented the CBE Bioremediation program to the University of Heidelberg and the University of Strasbourg, Germany, March 2002.   Dr. Elinor Pulcini, a CBE graduate and currently a Postdoctoral Scholar in the Department of Microbiology at MSU, gave a presentation "An Introduction to Biofilms" for the Spring Convention of the Montana Society for Clinical Laboratory Science, Bozeman, MT, April 4, 2002.   Drs. Michael Givskov, Søren Molin and Bill Costerton organized a Biofilm Method Workshop, - A PhD Course, BioCentrum, DTU, Copenhagen, Denmark, April 1-6, 2002. Presenters from the CBE were Bill Costerton, Jeff Leid, Paul Stoodley, and Paul Sturman.   Drs. Zbigniew Lewandowski and Haluk Beyenal, and graduate students Nurdan Yurt and Xianming Shi attended the NACE 2002 Conference, Denver, CO, April 7-11, 2002. Their presentations are listed below. Yurt, N., R. Avci, Z. Lewandowski, and J. Sears, "Passive Film Chemistry on 316L Stainless Steel Ennobled by Biomineralized Manganese"   Shi, X., R. Avci, and Z. Lewandowksi, "Microbially Deposited Manganese and Iron Oxides on Passive Metals - Their Chemistry, Distribution, and Consequences for Material Performance"   Lewandowski, Z. and A. Hamilton, "MIC of Stainless Steels as a Model System to Study Metal-Microbe Interactions" Dr. Anne Camper was an invited speaker at the NASA Astrobiology Meeting, Ames Research Center, San Jose, CA, April 7 -11, 2002. She presented "A Mode of Survival for Bacteria in Extreme Environments."   Dr. Anne Camper presented "Involvement of Humic Substances in Regrowth", at the NSF International/World Health Organization Symposium on HPC Bacteria in Drinking Water, Geneva Switzerland, April 21-24, 2002. She also presented a poster, "Heterotrophic Plate Count Organisms as Indicators."   Dr. Jeff Leid, as an invited lecturer, presented a seminar entitled, "Medically Relevant Biofilms and Chronic Infection" for the Thompson Hall Science and Math Seminar series at the University of Puget Sound, Tacoma, WA, April 11, 2002.   Drs. Jeff Leid and Mark Shirtliff presented a poster "Leukocyte Response to Maturing and Fully Mature Staphylococcus aureus Biofilms" at Experimental Biology 2002: Translating the Genome, in New Orleans, LA, April 20-24, 2002.   Drs. Bill Costerton and Marty Hamilton were presenters at the 1st OECD Efficacy Workshop on Certain Antimicrobial Biocides, in Arlington, Virginia, USA, April 22-24, 2002. Bill presented "Introduction to Biofilms," and Marty presented "Performance Standards."   __________________________________________   Theses   See theses abstracts at http://www.erc.montana.edu/Res-Lib99-SW/pubs/Theses/default.htm     __________________________________________   Web Watch   Biofilm Movies   Biofilm movies have increasingly been used as cited references for publications and grants. A CBE web page has been created to archive the biofilm movies referenced by CBE authors. You can find this Biofilm Movie web page in the Resource Library of the CBE web pages, at http://www.erc.montana.edu/Res-Lib99-SW/Movies/default.htm   _______   BiofilmsOnline.com   The Biofilm Institute, Inc. recently received funding from the Waksman Foundation for Microbiology to provide an educational resource for teachers, consumers and the media. See the May issue of BiofilmsOnline.com at http://www.BiofilmsOnline.com.    _______   Recent Web Updates   Check the Recent Web Updates link located on the CBE home page, to view the latest information posted on the CBE web.   See <http://www.erc.montana.edu/Recent%20Web%20Updates/default.htm>    __________________________________________   Newsletter Listserve   The CBE News Update is a listserve newsletter. If you need to subscribe or unsubscribe from the listserve, follow the directions at the following CBE website.   http://www.erc.montana.edu/Res-Lib99-SW/newsarchives/subscribe.htm   An alternative to subscribing to the listserve is to view the CBE News Update on our web page at http://www.erc.montana.edu/Ind-Col99-SW/Current_Newsletter/default.htm. Newsletter archives can be found at http://www.erc.montana.edu/Res-Lib99-SW/newsarchives/index.htm   __________________________________________   Diane Williams  editor of the CBE News Update