Lignolytic-consortium omics analyses reveal novel genomes and pathways involved in lignin modification and valorization

Autor(es):Mostrar menos -

Moraes, Eduardo C. ^[1] ; Alvarez, Thabata M. ^[2] ; Persinoti, Gabriela F. ^[1] ; Tomazetto, Geizecler ^[1] ; Brenelli, Livia B. ^[1] ; Paixao, Douglas A. A. ^[1] ; Ematsu, Gabriela C. ^[1] ; Aricetti, Juliana A. ^[1] ; Caldana, Camila ^[1] ; Dixon, Neil ^[3] ; Bugg, Timothy D. H. ^[4] ; Squina, Fabio M. ^[5]

Afiliação do(s) autor(es)

^[1] Ctr Nacl Pesquisa Energia & Mat, Lab Nacl Ciencia & Tecnol Bioetanol, Campinas - Brazil

^[2] UP, Master Program Ind Biotechnol, Curitiba, Parana - Brazil

^[3] Univ Manchester, Sch Chem, Manchester Inst Biotechnol, Manchester, Lancs - England

^[4] Univ Warwick, Dept Chem, Coventry, W Midlands - England

^[5] Univ Sorocaba, Programa Proc Tecnol & Ambientais, Sorocaba - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BIOTECHNOLOGY FOR BIOFUELS; v. 11, MAR 22 2018.
• Citações Web of Science: 10

Resumo

Background: Lignin is a heterogeneous polymer representing a renewable source of aromatic and phenolic bioderived products for the chemical industry. However, the inherent structural complexity and recalcitrance of lignin makes its conversion into valuable chemicals a challenge. Natural microbial communities produce biocatalysts derived from a large number of microorganisms, including those considered unculturable, which operate synergistically to perform a variety of bioconversion processes. Thus, metagenomic approaches are a powerful tool to reveal novel optimized metabolic pathways for lignin conversion and valorization. Results: The lignin-degrading consortium (LigMet) was obtained from a sugarcane plantation soil sample. The LigMet taxonomical analyses (based on 16S rRNA) indicated prevalence of Proteobacteria, Actinobacteria and Firmicutes members, including the Alcaligenaceae and Micrococcaceae families, which were enriched in the LigMet compared to sugarcane soil. Analysis of global DNA sequencing revealed around 240,000 gene models, and 65 draft bacterial genomes were predicted. Along with depicting several peroxidases, dye-decolorizing peroxidases, laccases, carbohydrate esterases, and lignocellulosic auxiliary (redox) activities, the major pathways related to aromatic degradation were identified, including benzoate (or methylbenzoate) degradation to catechol (or methylcatechol), catechol orthocleavage, catechol meta-cleavage, and phthalate degradation. A novel Paenarthrobacter strain harboring eight gene clusters related to aromatic degradation was isolated from LigMet and was able to grow on lignin as major carbon source. Furthermore, a recombinant pathway for vanillin production was designed based on novel gene sequences coding for a feruloyl-CoA synthetase and an enoyl-CoA hydratase/aldolase retrieved from the metagenomic data set. Conclusion: The enrichment protocol described in the present study was successful for a microbial consortium establishment towards the lignin and aromatic metabolism, providing pathways and enzyme sets for synthetic biology engineering approaches. This work represents a pioneering study on lignin conversion and valorization strategies based on metagenomics, revealing several novel lignin conversion enzymes, aromatic-degrading bacterial genomes, and a novel bacterial strain of potential biotechnological interest. The validation of a biosynthetic route for vanillin synthesis confirmed the applicability of the targeted metagenome discovery approach for lignin valorization strategies. (AU)

• Processo FAPESP: 13/03061-0 - Caracterização de frações de lignina extraídas do bagaço de cana-de-açúcar com propriedades antioxidantes
• Beneficiário: Lívia Beatriz Brenelli de Paiva
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 14/26152-4 - Prospecção de enzimas e otimização de vias metabólicas para produção de vanilina a partir de lignina do bagaço de cana de açúcar
• Beneficiário: Eduardo Cruz Moraes
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 15/50590-4 - Valorização da lignina em plantas de etanol celulósico: a conversão biocatalítica via ácido ferúlico a produtos químicos de alto valor
• Beneficiário: Fábio Márcio Squina
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Temático
• Processo FAPESP: 15/23279-6 - Análise metagenômica e metasecretômica de um consórcio microbiano enriquecido de fungos anaeróbicos degradador de bagaço de cana: prospecção de celulossomas e enzimas lignocelulolíticas
• Beneficiário: Geizecler Tomazetto
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado