Kang Sun-Young, Choi Oksik, Lee Jae Kyoung, Ahn Jung-Oh, Ahn Jong Seog, Hwang Bang Yeon, Hong Young-Soo
Chemical Biology Research Center, Korea Research Institute of Bioscience and Biotechnology, 30 Yeongudanji-ro, Ochang-eup, Chungbuk, 363-883, Republic of Korea.
Department of Pharmacy Graduate School, Chungbuk National University, Cheongju, 361-763, Republic of Korea.
Microb Cell Fact. 2015 Jun 10;14:78. doi: 10.1186/s12934-015-0268-7.
Styrene and its derivatives as monomers and petroleum-based feedstocks are valuable as raw materials in industrial processes. The chemical reaction for styrene production uses harsh reaction conditions such as high temperatures or pressures, or requires base catalysis with microwave heating. On the other hand, production of styrene and its derivatives in Escherichia coli is an environmental friendly process to produce conventional petroleum-based feedstocks.
An artificial biosynthetic pathway was developed in E. coli that yields 4-hydroxystyrene, 3,4-dihydroxystyrene and 4-hydroxy-3-methoxystyrene from simple carbon sources. This artificial biosynthetic pathway has a codon-optimized phenolic acid decarboxylase (pad) gene from Bacillus and some of the phenolic acid biosynthetic genes. E. coli strains with the tal and pad genes, the tal, sam5, and pad genes, and the tal, sam5, com, and pad genes produced 4-hydroxystyrene, 3,4-dihydroxystyrene and 4-hydorxy-3-methoxystyrene, respectively. Furthermore, these pathways were expressed in a tyrosine overproducing E. coli. The yields for 4-hydroxystyrene, 3,4-dihydroxystyrene and 4-hydorxy-3-methoxystyrene reached 355, 63, and 64 mg/L, respectively, in shaking flasks after 36 h of cultivation.
Our system is the first to use E. coli with artificial biosynthetic pathways for the de novo synthesis of 3,4-dihydroxystyrene and 4-hydroxy-3-methoxystyrene in a simple glucose medium. Similar approaches using microbial synthesis from simple sugar could be useful in the synthesis of plant-based aromatic chemicals.
苯乙烯及其衍生物作为单体和石油基原料在工业生产过程中是有价值的原材料。苯乙烯生产的化学反应需要高温或高压等苛刻的反应条件，或者需要碱催化和微波加热。另一方面，在大肠杆菌中生产苯乙烯及其衍生物是一种生产传统石油基原料的环保工艺。
在大肠杆菌中开发了一条人工生物合成途径，可从简单碳源生成4-羟基苯乙烯、3,4-二羟基苯乙烯和4-羟基-3-甲氧基苯乙烯。这条人工生物合成途径含有来自芽孢杆菌的密码子优化的酚酸脱羧酶（pad）基因和一些酚酸生物合成基因。含有tal和pad基因、tal、sam5和pad基因以及tal、sam5、com和pad基因的大肠杆菌菌株分别产生了4-羟基苯乙烯、3,4-二羟基苯乙烯和4-羟基-3-甲氧基苯乙烯。此外，这些途径在酪氨酸高产的大肠杆菌中表达。培养36小时后，摇瓶中4-羟基苯乙烯、3,4-二羟基苯乙烯和4-羟基-3-甲氧基苯乙烯的产量分别达到355、63和64毫克/升。
我们的系统首次利用具有人工生物合成途径的大肠杆菌在简单的葡萄糖培养基中从头合成3,4-二羟基苯乙烯和4-羟基-3-甲氧基苯乙烯。使用简单糖类进行微生物合成的类似方法可能有助于植物基芳香化学品的合成。
