Recently, the front cover of the internationally renowned academic journal Angewandte Chemie International Edition published the latest research progress in the field of renewable resource utilization by the Shanghai Jiaotong University School of Life Science and Technology, Professor Xu Ping of the National Key Laboratory of Microbial Metabolism. Temperature-directed biocatalysis for the sustainable production of aromatic aldehydes or alcohols'. Tao Fei, associate researcher for the co-corresponding author, postdoctoral Ni Jun and master student Gao Wei as co-first authors.
Lignin is the second most abundant biomass resource on Earth, and it is also the only renewable aromatic compound. Bio-based polymer is a new type of environmental protection material compared to traditional chemical materials. It is the focus of modern bio-manufacturing industry development. , It is also a hot industry direction for global green economy growth. The addition of aromatic units (aromatic aldehydes/alcohol monomers) to the bio-based polymer backbone can increase the hardness, hydrophobicity, and fire resistance of the polymer, and thus make use of the raw wood. The preparation of such materials by prime resources has attracted the attention of scientists from all countries. The variety and quantity of alcohol dehydrogenases in microbial cells will cause numerous side reactions, affecting the catalytic conversion efficiency of aromatic compounds and thus affecting the popularization and use of this method. The identification and knockout of many endogenous alcohol dehydrogenases in host cells is a huge challenge. Therefore, there is an urgent need to develop a new method to eliminate host endogenous alcohol dehydrogenase activity and accumulate aromatic aldehydes.
The team creatively introduced the aromatic aldehyde synthase gene of a thermophilic bacterium into a medium-temperature host and constructed a temperature-directed whole cell catalytic system. At low temperatures, the catalytic system is common to both exogenous and endogenous alcohol dehydrogenases. Under the action of the renewable resources, ferulic acid can be converted into vanillyl alcohol. With the increase of temperature, the endogenous alcohol dehydrogenase activity of the mesophile host is inhibited, while the function of thermophilic bacteria-derived enzymes is maintained, and ferulic acid is retained. Efficient conversion to the corresponding aromatic aldehyde vanillin. Subsequently, based on the same strategy, a variety of cinnamic acid derivatives were used as substrates to synthesize the corresponding aromatic aldehydes/aromatic alcohols. This novel strategy avoids host endogenous alcohols. In the cumbersome process of dehydrogenase knock-out, direct use of temperature controls the synthesis of aromatic aldehydes/aromatic alcohols, greatly simplifies the production process, and can be extended to the synthesis of many other aldehydes and aldehyde-based compounds. Has important practical significance and industrial application value.
The research work was supported by the National Natural Science Foundation of China (21777098, 31570101), Shanghai Youth Science and Technology Talents Sailing Plan (17YF1410300) and Shanghai Pujiang Talent Plan (15PJD019).
