A DOE BER User Facility for Structural and Chemical Insights on PlantSoil-Microbial Systems
Authors:
Aina Cohen* ([email protected]), Thomas Weiss ([email protected]), Jocelyn Richards, Ritimukta Sarangi, Britt Hedman, Keith Hodgson (PI)
Institutions:
SLAC National Accelerator Laboratory
URLs:
Abstract
The Structural Molecular Biology (SMB) resource at the Stanford Synchrotron Radiation Lightsource (SSRL) develops, operates, and supports state-of-the-art synchrotron radiation capabilities for enabling biological and environmental research using macromolecular crystallography (MC), small angle X-ray scattering (SAXS), X-ray absorption spectroscopy (XAS) and X-ray fluorescence (XRF) imaging techniques. As a user facility, the SMB resource provides the national scientific community access to these advanced capabilities primarily through general user proposals as well as a strong user support program, which includes outreach, training, and dissemination. The suite of instruments operated by the resource encompasses seven full time synchrotron beamlines at SSRL, four for MC, one for SAXS, two for XAS, and ~1.4 beamline equivalents spread out over six beamlines for μXRF imaging and advanced spectroscopy. Two state-of-the-art undulator microfocus beamlines are optimized for challenging micro-crystal and time-resolved MC measurements. The SAXS beamline is equipped with highly automated solution scattering robotics and features a state-of-the-art chromatography coupled SAXS setup as well as an exchangeable high flux multilayer monochromator for time-resolved experiments in the millisecond timescale. Three dedicated XRF imaging beamlines cover a range of spatial scales (micrometer to centimeter) and elements of biological importance (phosphorus, sulfur, potassium, calcium, and metals).
A powerful aspect of the XRF imaging beamlines is that they can perform µ-XAS to characterize the oxidation state, or chemical species, at a single point within a sample. Combining XRF with XAS is a tool for generating spatial distribution images of individual chemical species of an element within a sample. The synchrotron resource is managed and operated in a fully integrated and centrally coordinated manner, across all beamlines and techniques, facilitating cross technique structural investigations in biological and environmental research, covering length scales from Angstrom to centimeters. Recent results enabled by the SMB resource will be presented, highlighting the scientific potential of interlaboratory collaborations for a multi-technique approach to BER science made possible by a dedicated BER-supported outreach program at SSRL.