Turk Stefan C H J, Kloosterman Wigard P, Ninaber Dennis K, Kolen Karin P A M, Knutova Julia, Suir Erwin, Schürmann Martin, Raemakers-Franken Petronella C, Müller Monika, de Wildeman Stefaan M A, Raamsdonk Leonie M, van der Pol Ruud, Wu Liang, Temudo Margarida F, van der Hoeven Rob A M, Akeroyd Michiel, van der Stoel Roland E, Noorman Henk J, Bovenberg Roel A L, Trefzer Axel C
DSM Biotechnology Center , PO Box 1, 2600 MA Delft, The Netherlands.
University Medical Center Utrecht , PO Box 85060, 3508 AB Utrecht, The Netherlands.
ACS Synth Biol. 2016 Jan 15;5(1):65-73. doi: 10.1021/acssynbio.5b00129. Epub 2015 Nov 11.
Nylon-6 is a bulk polymer used for many applications. It consists of the non-natural building block 6-aminocaproic acid, the linear form of caprolactam. Via a retro-synthetic approach, two synthetic pathways were identified for the fermentative production of 6-aminocaproic acid. Both pathways require yet unreported novel biocatalytic steps. We demonstrated proof of these bioconversions by in vitro enzyme assays with a set of selected candidate proteins expressed in Escherichia coli. One of the biosynthetic pathways starts with 2-oxoglutarate and contains bioconversions of the ketoacid elongation pathway known from methanogenic archaea. This pathway was selected for implementation in E. coli and yielded 6-aminocaproic acid at levels up to 160 mg/L in lab-scale batch fermentations. The total amount of 6-aminocaproic acid and related intermediates generated by this pathway exceeded 2 g/L in lab-scale fed-batch fermentations, indicating its potential for further optimization toward large-scale sustainable production of nylon-6.
尼龙-6是一种用于多种应用的本体聚合物。它由非天然结构单元6-氨基己酸组成，即己内酰胺的线性形式。通过逆合成方法，确定了两条用于发酵生产6-氨基己酸的合成途径。这两条途径都需要尚未报道的新型生物催化步骤。我们通过对在大肠杆菌中表达的一组选定候选蛋白进行体外酶分析，证明了这些生物转化。其中一条生物合成途径以2-氧代戊二酸为起始物，包含产甲烷古菌中已知的酮酸延伸途径的生物转化。该途径被选择在大肠杆菌中实施，在实验室规模的分批发酵中，6-氨基己酸产量高达160 mg/L。在实验室规模的补料分批发酵中，该途径产生的6-氨基己酸和相关中间体的总量超过2 g/L，表明其在进一步优化以实现尼龙-6大规模可持续生产方面的潜力。
