Engineering a bzd cassette for the anaerobic bioconversion of aromatic compounds

• Published in: Microbial biotechnology 2017-11, Vol.10 (6), p.1418-1425
• Main Authors: Zamarro, María Teresa, Barragán, María J. L., Carmona, Manuel, García, José Luis, Díaz, Eduardo
• Format: Article
• Language: English
• Subjects: Acyl Coenzyme A - genetics; Acyl Coenzyme A - metabolism; Anaerobic conditions; Anaerobic microorganisms; Anaerobic processes; Anaerobiosis; Aromatic compounds; Azoarcus - genetics; Azoarcus - metabolism; Bacteria; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Benzoates; Benzoates - chemistry; Benzoates - metabolism; Biocatalysts; Biocompatibility; Bioconversion; Biodegradability; Biodegradation; Biodegradation, Environmental; Biotechnology; Brief Report; Brief Reports; Carbon; Carbon sources; Contaminants; Degradation; Denitrifying bacteria; Enzymes; Genetic engineering; Hydroxybutyrates - chemistry; Hydroxybutyrates - metabolism; Metabolic Engineering; Metabolism; Microorganisms; Polyhydroxybutyrate; Polymers; Toluene; Toluene - metabolism
• ISSN: 1751-7915; 1751-7915
• DOI: 10.1111/1751-7915.12746

Summary Microorganisms able to degrade aromatic contaminants constitute potential valuable biocatalysts to deal with a significant reusable carbon fraction suitable for eco‐efficient valorization processes. Metabolic engineering of anaerobic pathways for degradation and recycling of aromatic compounds is an almost unexplored field. In this work, we present the construction of a functional bzd cassette encoding the benzoyl‐CoA central pathway for the anaerobic degradation of benzoate. The bzd cassette has been used to expand the ability of some denitrifying bacteria to use benzoate as sole carbon source under anaerobic conditions, and it paves the way for future pathway engineering of efficient anaerobic biodegraders of aromatic compounds whose degradation generates benzoyl‐CoA as central intermediate. Moreover, a recombinant Azoarcus sp. CIB strain harbouring the bzd cassette was shown to behave as a valuable biocatalyst for anaerobic toluene valorization towards the synthesis of poly‐3‐hydroxybutyrate (PHB), a biodegradable and biocompatible polyester of increasing biotechnological interest as a sustainable alternative to classical oil‐derived polymers. Metabolic engineering of anaerobic pathways for degradation and recycling of aromatic compounds is an almost unexplored field. In this work we present the construction of a functional bzd cassette encoding the benzoyl‐CoA central pathway that has been used to expand the ability of some denitrifying bacteria to use benzoate as sole carbon source under anaerobic conditions. Moreover, a recombinant Azoarcus sp. CIB strain harboring the bzd cassette was shown to behave as a valuable biocatalyst for anaerobic toluene valorization towards the synthesis of the biodegradable and biocompatible poly‐3‐hydroxybutyrate (PHB) polymer.