Lignin Depolymerization Composition via High Resolution Mass Spectrometry
EMSL Project ID
60826
Abstract
Our research has focused on understanding the composition of lignin-derived carbon and energy sources for the growth of the triacylglycerol (TAG, a biodiesel precursor)-accumulating bacterium Rhodococcus opacus PD630 (hereafter R. Opacus). Our approach uses a catalytic process to depolymerize lignin into lignin breakdown products (LBPs), with advantageous reaction kinetics and a downstream microbial upgrading process, leveraging native aromatic catabolism pathways of R. Opacus to “biologically funnel” the heterogeneous substrates in the LBP into a value-added product with beneficial product selectivity and yield. In particular, we are interested in design of lignin catalytic depolymerization processes to improve the selective production of the set of compounds within a LBP that “fits into the entrance of the biological funnel” and that minimizes microbial growth inhibition. Control over LBP compositional distribution is enabled by extensive product characterization. However, LBP characterization is very difficult due its chemical complexity and heterogeneity. Thus, the aim of this limited scope proposal is to apply high-resolution mass spectrometry (HR-MS) to resolve components of LBPs. HR-MS analysis will be used to sort the constituents in LBPs by molecular weight and formula; heteroatom class (nitrogen, oxygen, sulfur, etc.); and type (degree of unsaturation, nominal oxidation state, carbon number, etc.). Our team, as well as research by others[1-4], has found that lignin depolymerization using calcined Cu-doped hydrotalcite or porous metal oxide (CuPMO) catalysts can effectively generate aromatic-rich liquids. In addition, we also know that the (1) concentration and type of metal loaded, (2) solvent, and (3) temperature/time profile play major roles in lignin depolymerization. The results of this limited scope research will allow us to understand and establish the fundamental relationships that control lignin depolymerization and determine LBP composition
Project Details
Project type
Limited Scope
Start Date
2023-07-01
End Date
2023-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members