# Microbial Upgrading of Lignin Depolymerization: Enhancing Efficiency with Lignin-First Catalysis.
> リグニン優先触媒分解と微生物アップグレードを組み合わせたハイブリッドリグニン変換プロセスの開発


## Abstract

Chemical lignin depolymerization typically yields a heterogeneous mixture of breakdown products. This study constructed a hybrid conversion scheme pairing reductive catalytic fractionation (RCF) of poplar biomass using a Pd/C catalyst with subsequent cultivation of Rhodococcus opacus PD630 on the resulting lignin breakdown products (LBPs). Compared with base-catalyzed depolymerization performed without Pd/C or molecular hydrogen, RCF-derived LBPs supported greater cell biomass accumulation per gram of feedstock. Residual cellulose after RCF exhibited enzymatic digestibility exceeding 40% saccharification yield. Techno-economic and life cycle analyses, modeled within a cellulosic bioethanol facility, showed a reduction in the minimum ethanol selling price from $4.07 to $3.94 per gallon, with global warming potentials between 29 and 30.5 CO2eq/MJ. The findings support the feasibility of an industrial biorefinery integrating lignin-first catalytic deconstruction with microbial valorization.

### Mechanism

RCF using Pd/C and molecular hydrogen modifies the composition of lignin breakdown products, improving their assimilability by R. opacus PD630 and simultaneously enhancing enzymatic saccharification of residual cellulose in the treated biomass.

## Bibliographic

- **Authors**: Ponukumati A, Carr R, Ebrahimpourboura Z, Hu Y, Narani A, Gao Y, et al.
- **Journal**: ChemSusChem
- **Year**: 2025 (2025-04-14)
- **PMID**: [39648819](https://pubmed.ncbi.nlm.nih.gov/39648819/)
- **DOI**: [10.1002/cssc.202400954](https://doi.org/10.1002/cssc.202400954)
- **Study type**: other
- **Delivery route**: not specified
- **Effect reported**: not assessed

## Delivery context

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)

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> **Cite as**: H2 Papers — PMID 39648819. https://h2-papers.org/en/papers/39648819
> **Source**: PubMed PMID [39648819](https://pubmed.ncbi.nlm.nih.gov/39648819/)