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Direct examination of natural and engineered environments has revealed that the majority of microorganisms in these systems live in structured communities termed biofilms. In addition to microbial cells, biofilms are comprised of a poorly characterized organic matrix commonly referred to as extracellular polymeric substance (EPS) that may play roles in facilitating microbial interactions and biogeochemical reactions including extracellular electron transfer. Using highresolution electron microscopy imaging, we have shown copious amounts of highly hydrated bacterial EPS to be produced during microbial metal reduction [1,2]. The juxtaposition of extracellular electron transfer proteins and nanoparticulate reduced metal suggested that EPS played a key role in metal capture and precipitation. Determining the chemical composition of biofilm-associated EPS and understanding how it functions and interacts with inorganic substrates including metal ions and mineral surfaces is needed to connect the molecular-scale biogeochemical processes to those at the microorganism-level, and provide insight to how microbes influence larger, pore-scale biogeochemical reactions.

In this paper we present the preliminary results from a new experimental technique to synchronize the pulses from a mode-locked Nd-YAG laser to the light pulses in the VUV storage ring at the National Synchrotron Light Source (NSLS). We describe a method to electronically change the delay time between the laser pulses and the synchrotron pulses. We also illustrate a method to overlap the synchrotron pulses with the laser pulses in space and time. Preliminary results will be presented for two experiments.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

The first Infrared (IR) Beamline at the Advanced Light Source (ALS), Beamline 1.4, is described. The design of the optical and mechanical systems are discussed, including choices and tradeoffs. The initial commissioning of the beamline is reported. The beamline, while designed primarily for IR microscopy and only initially instrumented for microscopy (with a Nicolet interferometer and microscope), will have the potential for surface science experiments at grazing incidence, and time-resolved visible spectroscopy.

Electron synchrotron storage rings, such as the VUV ring at the National Synchrotron Light Source (NSLS), produce short pulses of infrared (IR) radiation suitable for investigating the time-dependent phenomena in a variety of interesting experimental systems. In contrast to other pulses sources of IR, the synchrotron produces a continuum spectral output over the entire IR (and beyond), though at power levels typically below those obtained from laser systems. The infrared synchrotron radiation (IRSR) source is therefore well-suited as a probe using standard FTIR spectroscopic techniques. Here the authors describe the pump-probe spectroscopy facility being established at the NSLS and demonstrate the technique by measuring the photocarrier decay in a semiconductor.