Development of a dual-fluorescence reporter system for high-throughput screening of L-aspartate-α-decarboxylase

• 来源期刊: 生物化学与生物物理学报（英文版）
• 年，卷（期）: 2020,（12）
• 所属期刊栏目: Short Communication
• 页码范围: 1420-1426
• 页数: 7页
• 语种: 英文
• DOI: 10.1093/abbs/gmaa134

摘要

β-Alanine(3-aminopropionic acid)holds great potential in industrial application.It can be obtained through a chemical synthesis route,which is hazardous to the environment.It is well known that L-aspartate-α-decarboxylase(ADC)can convert L-aspartate to β-alanine in bacteria.However,due to the low activity of ADC,industrial production of β-alanine through the green biological route remains unclear.Thus,improving the activity of ADC is critical to reduce the cost of β-alanine production.In this study,we established a dual-fluorescence high-throughput system for efficient ADC screening.By measuring the amount of β-alanine and the expression level of ADC using two different fluorescence markers,we can rapidly quantify the relative activity of ADC variants.From a mutagenesis library containing 2000 ADC variants,we obtained a mutant with 33％increased activity.Further analysis revealed that mutations of K43R and P103Q in ADC significantly improved the yield of β-alanine produced by the whole-cell biocatalysis.Compared with the previous single-fluorescence method,our system can not only quantify the amount of lβ-alanine but also measure the expression level of ADC with different fluorescence,making it able to effectively screen out ADC variants with improved relative activity.The dual-fluorescence high-throughput system for rapid screening of ADC provides a good strategy for industrial production of β-alanine via the biological conversion route in the future.