Abstract
Bioconversion of lignin-rich streams requires microbial hosts capable of utilizing and tolerating heterogeneous mixtures of monomeric and oligomeric compounds. Promising strains such as Novosphingobium aromaticivorans F199, N. aromaticivorans JMN2, Pseudomonas putida KT2440, Rhodococcus opacus PD630, Rhodosporidium toruloides NBRC0880, Sphingobium lignivorans B1D3A, and S. lignivorans SYK-6 possess inherent catabolic abilities to utilize lignin-related compounds (LRCs). In this work, we compared the cellular fitness and catabolic capabilities of these six bacteria and one yeast on a lignin-rich stream, alkaline pretreated liquor (APL) from corn stover, and on representative aromatic and aliphatic compounds. First, a minimal medium recipe that supported the growth of all seven strains on LRCs was selected for the comparison. Using this minimal medium, P. putida KT2440 was found to have the fastest growth and greatest tolerance when grown on guaiacyl-type compounds, p-hydroxyphenyl-type compounds, aliphatic acids, corn stover APL, and a model chemical mixture, whereas the S. lignivorans strains had the fastest growth on the syringyl-type compound. After 120 h on APL, the change in total lignin was 10-12% and aromatic and aliphatic compound usage was 85-96% for all the strains except R. opacus PD630, which had minimal utilization of APL components. Although substantial conversion of high-molecular-mass lignin was not observed by any strains, the S. lignivorans strains showed detectable modification β-ether units. Additionally, the N. aromaticivorans strains liberated aromatic compounds, potentially from lignin oligomer modification. This work serves as a comparison of seven promising microbial strains for bioconversion of lignin-enriched streams, providing a foundation for evaluating suitable microbial platforms for lignin valorization and genetic reservoirs to source unique metabolic capabilities.
| Original language | English |
|---|---|
| Journal | Green Chemistry |
| DOIs | |
| State | Accepted/In press - 2024 |
Funding
This work was authored in part by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. This work was also authored in part by Oak Ridge National Laboratory, managed by UT-Battelle, LLC for the US DOE under Contract Number DE-AC05-00OR22725. This material is based upon work supported by the Center for Bioenergy Innovation (CBI), U.S. Department of Energy, Office of Science, Biological and Environmental Research Program under Award Number ERKP886. DRN, SL, and JR were supported by the Great Lakes Bioenergy Research Center, U.S. Department of Energy, Office of Science, Biological and Environmental Research Program under Award Number DE-SC0018409. This work was part of the DOE Joint BioEnergy Institute ( https://www.jbei.org ) supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research, through contract DE-AC02-05CH11231 between Lawrence Berkeley National Laboratory and the U. S. Department of Energy. Additional funding was provided by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Bioenergy Technologies Office, which additionally supported the analytical analysis of aromatic and aliphatic acids. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. Government. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for U.S. Government purposes.
| Funders | Funder number |
|---|---|
| National Renewable Energy Laboratory | |
| U.S. Department of Energy Office of Energy Efficiency and Renewable Energy BioEnergy Technologies Office | |
| Oak Ridge National Laboratory | |
| Center for Bioenergy Innovation | |
| Lawrence Berkeley National Laboratory | |
| Office of Science | |
| UT-Battelle | |
| U.S. Department of Energy | DE-AC05-00OR22725, DE-AC36-08GO28308 |
| Biological and Environmental Research | DE-AC02-05CH11231 |
| Great Lakes Bioenergy Research Center | DE-SC0018409 |
| Biological and Environmental Research program | ERKP886 |
