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Title 

Development of bioreactor system for L-tyrosine synthesis using thermostable tyrosine phenol-lyase

 

내열성 tyrosine phenol-lyase를 이용한 L-tyrosine 합성 생물반응시스템의 개발

Authors 

D Y KimEugene RhaSu-Lim ChoiJae Jun SongS P HongM H SungSeung Goo Lee

Publisher 

The Korean Society for Applied Microbiology

Issue Date 

2007

Citation 

Journal of Microbiology and Biotechnology, vol. 17, no. 1, pp. 116-122

Keywords 

bioconversionfed-batchL-tyrosinesymbiobacterium toebiityrosine phenol-lyaseammonium chloridemethanolphenolpyridoxal 5 phosphatetyrosine

Abstract 

An efficient enzyme system for the synthesis of L-tyrosine was developed using a fed-batch reactor with continuous feeding of phenol, pyruvate, and ammonia. A thermo- and chemostable tyrosine phenol-lyase from Symbiobacterium toebii was employed as the biocatalyst in this work. The enzyme was produced using a constitutive expression system in Escherichia coli BL21, and prepared as a soluble extract by rapid clarification, involving treatment with 40% methanol in the presence of excess ammonium chloride. The stability of the enzyme was maintained for at least 18 h under the synthesis conditions, including 75 mM phenol at pH 8.5 and 40°C. The fed-batch system (working volume, 0.5 ?1) containing 1.0 kU of the enzyme preparation was continuously fed with two substrate preparations: one containing 2.2 M phenol and 2.4 M sodium pyruvate, and the other containing 0.4 mM pyridoxal-5-phosphate and 4 M ammonium chloride (pH 8.5). The system produced 130 g/l of L-tyrosine within 30 h, mostly as precipitated particles, upon continuous feeding of the substrates for 22 h. The maximum conversion yield of L-tyrosine was 94% on the basis of the supplied phenol.

ISSN 

1017-7825

Appears in Collections

1. Journal Articles > Journal Articles

Registered Date

2019-05-02


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