Outer Membrane Vesicles Catabolize Lignin-Derived Aromatic Compounds in Pseudomonas putida KT2440

Journal Article · Fri Apr 03 00:00:00 EDT 2020 · Proceedings of the National Academy of Sciences of the United States of America

DOI:https://doi.org/10.1073/pnas.1921073117· OSTI ID:1659932

Salvachua, Davinia ; Werner, Allison Z. ; Pardo, Isabel ; Michalska, Martyna; Black, Brenna A.; Donohoe, Bryon S.; Haugen, Stefan J.; Katahira, Rui; Notonier, Sandra; Ramirez, Kelsey J.; Amore, Antonella; Purvine, Samuel O.; Zink, Erika M.; Abraham, Paul E.; Giannone, Richard J.; Poudel, Suresh; Laible, Philip D.; Hettich, Robert L.; Beckham, Gregg T.

Lignin is an abundant and recalcitrant component of plant cell walls. While lignin degradation in nature is typically attributed to fungi, growing evidence suggests that bacteria also catabolize this complex biopolymer. However, the spatiotemporal mechanisms for lignin catabolism remain unclear. Improved understanding of this biological process would aid in our collective knowledge of both carbon cycling and microbial strategies to valorize lignin to value-added compounds. Here, we examine lignin modifications and the exoproteome of three aromatic–catabolic bacteria: Pseudomonas putida KT2440, Rhodoccocus jostii RHA1, and Amycolatopsis sp. ATCC 39116. P. putida cultivation in lignin-rich media is characterized by an abundant exoproteome that is dynamically and selectively packaged into outer membrane vesicles (OMVs). Interestingly, many enzymes known to exhibit activity toward lignin-derived aromatic compounds are enriched in OMVs from early to late stationary phase, corresponding to the shift from bioavailable carbon to oligomeric lignin as a carbon source. In vivo and in vitro experiments demonstrate that enzymes contained in the OMVs are active and catabolize aromatic compounds. Taken together, this work supports OMV-mediated catabolism of lignin-derived aromatic compounds as an extracellular strategy for nutrient acquisition by soil bacteria and suggests that OMVs could potentially be useful tools for synthetic biology and biotechnological applications.

• Research Organization: National Renewable Energy Lab. (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Sustainable Transportation Office. Bioenergy Technologies Office
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1659932
• Report Number(s): NREL/JA-5100-76402; MainId:6619; UUID:9541e3db-6e69-ea11-9c31-ac162d87dfe5; MainAdminID:13658
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Vol. 117, Issue 17
• Country of Publication: United States
• Language: English

Related Subjects

BIOMASS FUELS
carbon cycling
catabolism
lignin
microbial conversion