Lignin as a byproduct can be obtained from agricultural wastes and biorefinery. In this study, we sought to develop Escherichia coli-based whole-cell biocatalysis for converting lignin-derived isoeugenol into cis,cis-muconic acid (ccMA). Recombinant E. coli expressing aromatic dioxygenase from Thermothelomyces thermophila and aldehyde dehydrogenase from Saccharomyces cerevisiae could efficiently convert isoeugenol to vanillic acid (VAN). However, we found that the demethylation of VAN by VanAB from Pseudomonas putida was severely inhibited by a high concentration of isoeugenol, which prompted us to develop a two-step approach to the production of ccMA from isoeugenol. Upon adjustment of the feeding strategy and optimization of the pH conditions, 43.8 mM ccMA was produced from 50 mM isoeugenol-derived VAN by recombinant E. coli expressing VanAB from P. putida, GDC from Talaromyces atroroseus, and CatA from Acinetobacter radioresistens. This work is a pioneering study in the evaluation of E. coli-based whole-cell biocatalysis for lignin valorization.

中文翻译：

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木质素衍生原料通过全细胞生物催化生物转化为粘康酸

木质素副产物可以从农业废料和生物精炼厂获得。在这项研究中，我们试图开发基于大肠杆菌的全细胞生物催化，以将木质素衍生的异丁香酚转化为顺式，顺式-粘康酸（ccMA）。表达嗜热嗜热菌的芳香族双加氧酶和酿酒酵母的醛脱氢酶的重组大肠杆菌可以有效地将异丁香酚转化为香草酸（VAN）。然而，我们发现VanAB可以将恶臭假单胞菌的VanAB脱甲基异丁香酚的高浓度严重抑制了它的活性，这促使我们开发了一种从异丁香酚生产ccMA的两步法。通过调整饲喂策略和优化pH条件，重组大肠杆菌表达了来自恶臭丁香酚的50 mM VAN，产生了43.8 mM ccMA，该表达来自恶臭假单胞菌的VanAB，来自Talaromyces atroroseus的GDC和不动杆菌的CatA 。这项工作是在评估基于大肠杆菌的木质素增值的全细胞生物催化方面的开创性研究。