Enzymatic production of 4-hydroxyphenylacetaldehyde by oxidation of the amino group of tyramine with a recombinant primary amine oxidase. (May 2020)

• Record Type: Journal Article
• Authors: Yu, Tianqi; Yin, Yifan; Ge, Yihe; Cheng, Shiwei; Zhang, Xingxiao; Feng, Zhibin; Zhang, Juan
• Is Part Of: Process biochemistry. Volume 92(2020)
• Page Start: 105
• Page End: 112
• Publication Date: 2020-05
• Subjects: Primary amine oxidase -- 4-hydroxyphenylacetaldehyde -- Biotransformation -- Biphasic biocatalytic system; Biochemical engineering -- Periodicals; Biotechnology -- Periodicals; Biochemistry -- periodicals; Biotechnology -- periodicals; Chemical Engineering -- periodicals; Génie biochimique -- Périodiques; Biotechnologie -- Périodiques; Biochemical engineering; Biotechnology; Periodicals; 660.63
• DOI: 10.1016/j.procbio.2020.03.007
• Languages: English
• ISSNs: 1359-5113

Abstract

Graphical abstract: Highlights: A biphasic system was developed to relieve product inhibition. An obviously higher concentration of tyramine (120 mM) was used in the biphasic system than in the aqueous system. 4-Hydroxyphenylacetaldehyde was obtained in 76.5 % yield (91.8 mM) in the biphasic system. Abstract: In this study, an efficient enzymatic process for the synthesis of 4-hydroxyphenylacetaldehyde (4-HPAA) from tyramine was developed using whole cells of recombinant Escherichia coli co-expressing primary amine oxidase (PrAO) from E. coli and catalase (CAT) from Bacillus pumilus . The reaction conditions for the synthesis of 4-HPAA were systematically optimized starting from a monophasic aqueous buffer. The optimum reaction temperature, pH, and biocatalyst loading were 33 °C, 7.5, and 20 g/L wet cells, respectively. Substrate feeding strategies were employed to alleviate substrate inhibition, providing a 14.8 % increase in yield. A biphasic catalytic system was explored to avoid product inhibition and thus further improve the 4-HPAA yield. Ethyl acetate was found to be the best organic solvent, and the optimum volume ratio of the organic phase to the aqueous phase was 40 % (v/v). Under the optimized conditions on a 1 L scale, a yield of 76.5 % was obtained with a substrate concentration of 120 mM. Thus, the bioconversion was more efficient in the ethyl acetate/buffer biphasic system than in the monophasic aqueous system, and the yield of 4-HPAA was improved 1.89-fold.