Spectral Imaging for Bioenergy Research

Jerilyn A. Timlin, Sandia National Laboratories**, Bioenergy and Defense Technologies, Albuquerque, NM

Photosynthetic organisms possess endogenous pigments such as chlorophylls and carotenoids that function to harvest the energy from sunlight and transfer this energy to the reaction center of the cell. In order to facilitate efficient energy transfer, photosynthetic pigments are collocated in pigment-protein complexes and have an inherently high degree of spectral overlap. Importantly, the identity, abundance, and localization of photosynthetic pigments vary from organisms to organisms and are dynamically regulated in response to changing environmental conditions. Spectral imaging methods coupled with multivariate analysis are uniquely suited to untangle the highly overlapped spectral signatures from photosynthetic pigments and reveal global pigment localization and dynamics in intact, living cells. In this talk I will introduce the state-of-the-art in spectral imaging and multivariate analysis methods with an emphasis on preprocessing techniques that we have developed for robust analysis.  Examples will highlight applications of hyperspectral confocal fluorescence microscopy and hyperspectral confocal Raman microscopy to identify and map multiple photosynthetic pigments in cyanobacteria, green algae, and land plants in response to changing conditions (environmental, genetic differences, etc.). These methods provide increased fundamental understanding of global pigment dynamics and function within and across photosynthetic organisms. The results have important implications for synthetic biology, genetic engineering, and development of biohybrid or bio-inspired devices.

**Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

Dr. Timlin is a distinguished member of the technical staff in the Bioenergy & Defense Technologies group at Sandia National Laboratories.  She received her Ph.D. in Analytical Chemistry from the University of Michigan in 2000 for her research on the development of Raman spectroscopic imaging and image analysis to visualize the chemistry involved in repair and remodeling of bone tissue..  Dr. Timlin’s current research focuses on developing and applying advanced spectroscopy, microscopy, spectroscopic imaging, and analysis methods to understand complex relationships and dynamics in multi-component biological systems – systems relevant to both emerging infectious disease and bioenergy/biofuels.  Her work sits at the interface of analytical chemistry and biology and includes a strong interdisciplinary component.   Dr. Timlin’s publications span multiple spatial scales and include areas such as nanoparticle interactions with immune cell, characterization mast cell synapse formation, identification of early markers for immune response to gram(-) bacteria using vibrational spectroscopy, discovery of spectroscopic markers for algal health and productivity in biofuels relevant strains, and localization photosynthetic pigments and proteins with highly overlapped spectral properties in live cyanobacteria and algae. She has published more than 35 papers in high impact journals.