Office: Cristol Chemistry 358
Office Phone: 303 492 7914
Lab: Cristol Chemistry 320, 322
Lab Phone: 303 492 8889, 303 492 5304
Fax:303 492 1149
Group Website: Fall Lab
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.



Ph.D.: University of California, Los Angeles, 1970
Fellow and affiliate of the Cooperative Institute for Research in Environmental Sciences
University of Colorado Faculty Fellowship, 1992, 1999
National Research Council Fellow, 1987

Environmental Biochemistry

My research program concerns environmental biochemistry, addressing the question: How do biochemical reactions alter the atmospheric environment? More specifically, we investigate mechanisms plants and microorganisms use to produce volatile or ganic compounds (VOCs) that enter the atmosphere. In addition, we try to understand the regulation of VOC biosynthesis and emission, and the biological rationales for formation of these organic compounds. These are significant issues when you consider that biogenic VOCs are emitted in huge amounts on a global scale, and play a major role in shaping the "health of the atmosphere" (e.g. triggering formation of ozone or depletion of OH radicals). We are also collaborating in development of analytic al methods and in field experiments with atmospheric scientists at NCAR and NOAA laboratories in Boulder, and at the University of Innsbruck, Austria. Some of these topics are highlighted below, and each is further discussed on the Fall Lab webpage.

Biochemical mechanisms:

  • characterization of isoprene synthases from leaf chloroplasts and bacteria from leaf chloroplasts and bacteria
  • "safety valve" mechanism for leaf acetaldehyde release

Biochemical controls on VOC formation

  • on-off switching of isoprene formation during bacterial growth
  • regulation of isoprene formation in chloroplasts by atmospheric CO2

Bioanalytical methods

  • application of chemical ionization mass spectrometry methods to VOC analysis
  • VOC flux determination by eddy correlation methods

Field investigations

  • crop harvesting as a major source of reactive VOCs
  • VOC release during leaf senescence in deciduous forests

Selected Publications

T.N. Rosenstiel, M.J. Potosnak, K.L. Griffin, R. Fall, and R.K. Monson (2003) Elevated CO2 uncouples growth and isoprene emission in an agriforest ecosystem. Nature, 421, 256-259.

J. de Gouw, C. Warneke, T. Karl, G. Eerdekens, C. van der Veen, and R. Fall (2003) Sensitivity and specificity of atmospheric trace gas detection by proton-transfer-reaction mass spectrometry. Int. J. Mass Spectrom., 223, 365-382.

A. J. Curtis, C. C. Grayless, and R. Fall (2002) Simultaneous determination of cyanide and carbonyls in cyanogenic plants by gas chromatography-electron capture/photoionization detection. Analyst 127, 1446-1449.

M.C. Shirk, W.P. Wagner and R. Fall (2002) Isoprene formation in Bacillus subtilis: A barometer of central carbon assimilation in a bioreactor? Biotechnol. Prog., 18, 1109-1115.

T. Karl, R. Fall, T. Rosenstiel, P. Prazeller, M. Duane, G. Seufert, and W. Lindinger (2002) On-line analysis of the 13CO2 labeling of leaf isoprene suggests multiple subcellular origins of isoprene precursors. Planta, 215, 894-905.

T. Sivy, M.C. Shirk, and R. Fall (2002) Isoprene synthase activity parallels fluctuations of isoprene release during growth of Bacillus subtilis. Biochem. Biophys. Res. Commun., 294, 71-75.

T. Karl, A.J. Curtis, T.N. Rosenstiel, R.K. Monson, and R. Fall (2002) Transient releases of acetaldehyde from tree leaves--products of a pyruvate overflow mechanism? Plant Cell Environ., 25, 1121-1131.