Flow
Cytometry Facility
The Marine Science flow cytometry facility, was established in 1983 for the purpose of analyzing marine microflora. Instrumentation, an Ortho IIs, was modified to become one of the best available for analyzing small organisms. It is supported by a Coulter Model II Multisizer for electronically counting and sizing organisms. The cytometer is unique with capabilities for the quantitative analysis of the DNA content and dry mass of aquatic bacteria, organisms that comprise about half the biomass of most natural water systems and control major aspects of marine chemistry. Other capabilities include the analysis of protein content and membrane potential, and genome size in single cells and ability to sort selected microbial populations. Capabilities extend from organisms 0.1 µm3 to 500 µm3 cells, and include bacteria, non-chaining phytoplankton, and mammalian cell and organelle preparations.
Data uses include unique ability to establish the biomass responsible for measurements of chemical dynamics and therefore provide a basis for measurements of activity. This activity is also reflected by the DNA content of individual cells or groups as shown. Changes in these can be followed over season, location and depth, and when radiolabeled, can be sorted and analyzed to establish the relative activity of these groups.
Our analysis rate is about 10 samples per day at a cost of $1000, with data workup costs of $500 per day.
Growth kinetics laboratory
The laboratory of D. K. Button is devoted to understanding the dynamics of aquatic microbial processes with special attention to bacteria. Areas of focus are nutrient kinetics, analysis by flow cytometry, and isolation technology. Areas under development are genomics and proteomics. We study bacterial dynamics because it is the major recycling component for organic carbon in the oceans, but one that is only beginning to be understood. Moreover, while functioning in a complex environment with a small genome, these organisms offer a route to improved understanding of ecosystem control.
References
Button, D. K. 2002. Kinetics (Microbial): theory and applications. In the encyclopedia of environmental microbiology. G. Bitton, editor. Wiley. pp1738-1748
Button, D. K. 2001 Isolation of oligobacteria. In Marine Microbiology, p161-173. J. Paul, Editor. Academic Press
Button, D. K. And B. R. Robertson. 2001. DNA content of heterotrophic bacterioplankton by flow cytometry. Appli. Environ. Microbiol. 67 (4), 1636-1645
Button, D. K., and B. R. Robertson. 2000. Effect of nutrient kinetics and cytoarchitecture on bacterioplankton size. Limnol.Oceanogr. 45 499-505..
Robertson, B. R., and D. K. Button. 1999. Bacterial biomass from measurements of forward light scatter intensity by flow cytometry. In P. Robinson (ed.), Current Protocols in Cytometry. John Wiley & Sons, New York. 1: 11.9.1-10.
Button, D. K. 1998. Nutrient uptake by microorganisms according to kinetic parameters from theory as related to cytoarchitecture. Microbiol. Mol. Biol. Rev. 62:636-645.
Button, D. K., B. R. Robertson, T. Schmidt, and P. Lepp. 1998. A small, dilute-cytoplasm, high-affinity, novel bacterium isolated by extinction culture that has kinetic constants compatible with growth at measured concentrations of dissolved nutrients in seawater. Appl. Environ. Microbiol.64:4467-4476.
Quang, P., D. K. Button, and B. R. Robertson. 1998. Use of species distribution data in the determination of bacterial viability by extinction culture of aquatic bacteria. J. Microbiol. Methods 33:203-210.
Robertson, B. R., D. K. Button, and A. L. Koch. 1998. Determination of the biomasses of small bacteria at low concentration in a mixture of species with forward light scatter measurements by flow cytometry. Appl. Environ. Microbiol. 64:3900-3909.
University of Alaska Fairbanks
Institute of Marine Science
School of Fisheries and Ocean Sciences
Resources
Derivations Associated with the Kinetics of Growth and Substrate Uptake for Microorganisms (330 KB pdf; modified April 15, 2004)