Production of biopolymer precursors beta-alanine and L-lactic acid from CO2 with metabolically versatile Rhodococcus opacus DSM 43205

Abstract

Hydrogen oxidizing autotrophic bacteria are promising hosts for conversion of CO2 into chemicals. In this work, we engineered the metabolically versatile lithoautotrophic bacterium R. opacus strain DSM 43205 for synthesis of polymer precursors. Aspartate decarboxylase (panD) or lactate dehydrogenase (ldh) were expressed for beta-alanine or L-lactic acid production, respectively. The heterotrophic cultivations on glucose produced 25 mg L−1 beta-alanine and 742 mg L−1 L-lactic acid, while autotrophic cultivations with CO2, H2, and O2 resulted in the production of 1.8 mg L−1 beta-alanine and 146 mg L−1 L-lactic acid. Beta-alanine was also produced at 345 μg L−1 from CO2 in electrobioreactors, where H2 and O2 were provided by water electrolysis. This work demonstrates that R. opacus DSM 43205 can be engineered to produce chemicals from CO2 and provides a base for its further metabolic engineering.

A Redox Proteomics Approach for Decoding Lignin to Lipid Conversion by Rhodococci

“…One novel approach for regenerating reducing power could be supplementing Rhococcus cultures with hydrogen (perhaps from a hydrogen-producing microorganism). Our results con rm expression and differential oxidation of a cytoplasmic [NiFe(Se)]hydrogenase [75][76][77].…”

A modular toolkit for environmentalRhodococcus, Gordonia, andNocardiaenables complex metabolic manipulation

“…R. ruber C208 and R. erythropolis DCL14 can degrade solid polyolefins and paraffin wax, respectively (16)(17)(18). R. opacus MR11 encodes a functional Calvin-Benson-Bassham cycle and a hydrogenase cluster that enables fully autotrophic growth (19), and several plant-associated R. qingshengii isolates either produce plant growth regulators or fix inorganic nitrogen (20,21). Importantly, these genera are easily maintained in the laboratory under aerobic and mesophilic conditions, and they do not require specialized growth media nor handling precautions.…”

Enrichment of halotolerant hydrogen-oxidizing bacteria and production of high-value-added chemical hydroxyectoine using a hybrid biological–inorganic system

“…Such in situ water electrolysis mitigates the mass transfer limitation of hydrogen gas to the medium ( Nangle et al, 2017 ). Utilizing genetically engineerable HOB (e.g., Cupriavidus necator H16 and Rhodococcus opacus DSM 43205) offers significant flexibility to the system and expands the range of possible products ( Liu et al, 2016 ; Nyyssölä et al, 2021 ; Salusjärvi et al, 2022 ). To date, HBI systems have successfully produced chemicals including biofuels, fatty acids, biopolymers (and their precursors), biofertilizers, and dietary compounds ( Torella et al, 2015 ; Liu et al, 2016 ; Brigham, 2019 ; Nyyssölä et al, 2021 ; Salusjärvi et al, 2022 ; Wu et al, 2022 ).…”

“…Utilizing genetically engineerable HOB (e.g., Cupriavidus necator H16 and Rhodococcus opacus DSM 43205) offers significant flexibility to the system and expands the range of possible products (Liu et al, 2016;Nyyssölä et al, 2021;Salusjärvi et al, 2022). To date, HBI systems have successfully produced chemicals including biofuels, fatty acids, biopolymers (and their precursors), biofertilizers, and dietary compounds (Torella et al, 2015;Liu et al, 2016;Brigham, 2019;Nyyssölä et al, 2021;Salusjärvi et al, 2022;Wu et al, 2022). However, for this technology to be a viable option for CO 2 utilization, it is necessary to improve its energy and economic efficiencies.…”