(144g) Muconic Acid Production from an Engineered Rhodococcus Opacus

Zhaoxian Xu, Mingjie Jin*

School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.

^*Corresponding Authors: Prof. Mingjie Jin, E-mail address: jinmingjie@njust.edu.cn

Abstract

With the advances of biorefinery technologies via biochemical route, cellulose and hemicellulose in lignocellulose can be converted to biofuels and various chemicals. The remaining lignin is projected to be burned for powering the biorefinery plant. By now, several strategies have emerged for lignin valorization, including thermochemical treatments, homogeneous catalysis and heterogeneous catalysis. Recently, bacterial systems have drawn an increasing attention for lignin valorization due to their rapid growth, biochemical versatility, and powerful environmental adaptability.

Muconic acid is an important compound which can be converted into many downstream products, including bioplastics including nylon-6,6, polyurethane, and polyethylene terephthalate. Some bacteria could produce muconic acid when various aromatic chemical compounds are applied as the substrates. Based on this point, some Pseudomonas putida have been engineered for muconic acid biosynthesis from lignin components. Rhodococcus sp. is another efficient lignin-utilization bacteria which could synthesize amount of lipid from lignin. In this work, the metabolic network of protocatechuate in Rhodococcus Opacus PD630 was reshaped for muconic acid production using lignin as substrates, including the deletion of the protocatechuate 3,4-dioxygenase, muconate cycloisomerase, catechol 2,3-dioxygenase and the expression of protocatechuate decarboxylase.

Keywords: Rhodococcus Opacus; lignin; muconic acid; metabolic engineering.

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