p-Coumaric acid (p-CA) is a bioactive natural product and an important industrial material for pharmaceuticals and nutraceuticals. It can be synthesized from deamination of l-tyrosine by tyrosine ammonia lyase (TAL). In this work, we discovered two aromatic amino acid lyase genes, Sas-tal and Sts-tal, from Saccharothrix sp. NRRL B-16348 and Streptomyces sp. NRRL F-4489, respectively, and expressed them in Escherichia coli BL21(DE3). The two enzymes were functionally characterized as TAL. The optimum reaction temperature for Sas-TAL and Sts-TAL is 55 °C and 50 °C, respectively; while, the optimum pH for both TALs is 11. Sas-TAL had a k_cat/K_m value of 6.2 μM⁻¹ min⁻¹, while Sts-TAL had a much higher efficiency with a k_cat/K_m value of 78.3 μM⁻¹ min⁻¹. Both Sts-TAL and Sas-TAL can also take l-phenylalanine as the substrate to yield trans-cinnamic acid, and Sas-TAL showed much higher phenylalanine ammonia lyase activity than Sts-TAL. Using E. coli/Sts-TAL as a whole-cell biocatalyst, the productivity of p-CA reached 2.88 ± 0.12 g (L h)⁻¹, which represents the highest efficiency for microbial production of p-CA. Therefore, this work not only reports the identification of two new TALs from actinomycetes, but also provides an efficient way to produce the industrially valuable material p-CA.

p香豆酸（p -CA）是生物活性天然产物和重要的工业材料，医药品和营养制品。它可以由酪氨酸氨裂合酶（TAL）脱去1-酪氨酸来合成。在这项工作中，我们发现了来自Saccharothrix sp。的两个芳香族氨基酸裂解酶基因Sas-tal和Sts-tal。NRRL B-16348和链霉菌sp。NRRL F-4489分别在大肠杆菌BL21（DE3）中表达它们。两种酶在功能上称为TAL。Sas-TAL和Sts-TAL的最佳反应温度分别为55°C和50°C。同时，两种TAL的最佳pH均为11。k _cat / K _m值为6.2μM- ¹  min ^-1，而Sts-TAL的效率更高，k _cat / K _m值为78.3μM ^-1  min ^-1。Sts-TAL和Sas-TAL都可以使用1-苯丙氨酸作为底物，生成反式肉桂酸，并且Sas-TAL显示的苯丙氨酸氨裂合酶活性比Sts-TAL高得多。使用大肠杆菌/ Sts-TAL作为全细胞生物催化剂，对-CA的生产率达到2.88±0.12 g（L h）^-1，代表了微生物生产p -CA的最高效率。因此，这项工作不仅报告了从放线菌中鉴定出两种新的TAL，而且为生产具有工业价值的材料p -CA提供了有效的方法。