Lignin valorization by bacterial genus Pseudomonas: State-of-the-art review and prospects

The most prominent aromatic feedstock on Earth is lignin, however, lignin valorization is still an underrated subject. The principal preparatory strategies for lignin valorization are fragmentation and depolymerization which help in the production of fuels and chemicals. Owing to lignin's structural heterogeneity, these strategies result in product generation which requires tedious separation and purification to extract target products. The bacterial genus Pseudomonas has been dominant for its lignin valorization potency, owing to a robust enzymatic machinery that is used to funnel variable lignin derivatives into certain target products such as polyhydroxyalkanotes (PHAs) and cis, cis-muconic acid (MA). In this review, the potential of genus Pseudomonas in lignin valorization is critically reviewed along with the advanced genetic techniques and tools to ease the use of lignin/lignin-model compounds for the synthesis of bioproducts. This review also highlights the research gaps in lignin biovalorization and discuss the challenges and possibilities for future research.

Automated summary

Lignin, the most prominent aromatic feedstock on Earth, is still an underrated subject in terms of valorization. The principal preparatory strategies for lignin valorization involve fragmentation and depolymerization to produce fuels and chemicals, which require tedious separation and purification due to lignin's structural heterogeneity. Genus Pseudomonas bacteria are dominant in lignin valorization, thanks to their robust enzymatic machinery that can convert lignin derivatives into target products such as PHAs and MA. This review critically examines the potential of Genus Pseudomonas in lignin valorization and discusses advanced genetic techniques to facilitate the synthesis of bioproducts using lignin compounds.