Project description:Lignin is a universal waste product of the agricultural industry and is currently seen as a potential feedstock for more sustainable manufacturing. While it is the second most abundant biopolymer in the world, most of it is currently burned as it is a very recalcitrant material. Many recent studies, however, have demonstrated the viability of biocatalysis to improve the value of this feedstock and convert it into more useful chemicals, such as polyhydroxybutyrate, and clean fuels like hydrogen and n-butanol. Rhodopseudomonas palustris is a gram-negative bacterium which demonstrates a plethora of desirable metabolic capabilities, including aromatic catabolism useful for lignin degradation. This study uses a multi-omics approach, including the first usage of CRISPRi in R. palustris, to investigate the lignin consumption mechanisms of R. palustris, the essentiality of redox homeostasis to lignin consumption, elucidate a potential lignin catabolic superpathway, and enable more economically viable sustainable lignin valorization processes.
Project description:The Trametes versicolor genome is predicted to encode many enzymes that can effectively degrade lignin, making it a has potentially useful application intool for biopulping and biobleaching. Poplar is an important and widely cultivated species of tree species, which isand extensively applied used in the pulping industry. However, the wood degradation mechanism of T. versicolor from transcriptomic level is not clear. To reveal identify the enzymes that contributeing to lignocellulose degraredauction and its degradation mechanisms, we evaluated transcriptomic how study theof T. versicolor transcriptome was changes during evaluated growthing on the poplar wood relative to growth on glucose medium. 853 genes were differentially expressed;, 360 genes were up-regulated on poplar wood, and 493 genes were down-regulated on poplar wood. Notably, most genes relative involved into lignin degradation were up-regulated, including eight lignin peroxidase (LiP) genes, and two manganese peroxidase (MnP) genes etc. Genes encoding cellulose and hemicelluloses degrading-enzymesation were mostly down-regulated, including six endo-β-1, 4-glucanase genes, three cellobiohydrolase I genes, and one cellobiohydrolase II gene, etc. MeanwhileAdditionally, expression of more significant expansion of P450s in T. versicolor genome, along with differences in carbohydrate- and lignin-degrading enzymes, could bewere correlated withto poplar wood degradation. Our results revealed transcriptomic characterizeation transcriptomic changes related toof lignocellulose degradation. Therefore, our results cwould be benuseful for the development ofefit T. versicolor as a tool to improve the efficiency of lignin degradation, and provide a theoretical foundation for a new paper pulp manufacturing processe 1,T.versicolor groewn on PDA medium. 2, T. versicolor growing on the a glucose carbon medium of glucose. 3, T. versicolor growing on poplar medium