Characterization of an Isoeugenol Monooxygenase (Iem) from Pseudomonas nitroreducens Jin1 That Transforms Isoeugenol to Vanillin

2013 ◽  
Vol 77 (2) ◽  
pp. 289-294 ◽  
Author(s):  
Ji-Young RYU ◽  
Jiyoung SEO ◽  
Sunhwa PARK ◽  
Joong-Hoon AHN ◽  
Youhoon CHONG ◽  
...  
2010 ◽  
Vol 192 (3) ◽  
pp. 201-209 ◽  
Author(s):  
Ji-Young Ryu ◽  
Jiyoung Seo ◽  
Tatsuya Unno ◽  
Joong-Hoon Ahn ◽  
Tao Yan ◽  
...  

2007 ◽  
Vol 55 (21) ◽  
pp. 8556-8561 ◽  
Author(s):  
Tatsuya Unno ◽  
Soo-Jin Kim ◽  
Robert A. Kanaly ◽  
Joong-Hoon Ahn ◽  
Su-Il Kang ◽  
...  

2014 ◽  
Vol 50 (3) ◽  
pp. 210-215
Author(s):  
Ngoc Tuan Nguyen ◽  
Kyoung Lee ◽  
Ju Beom Kang ◽  
Shir-Ly Huang

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1199
Author(s):  
Xin-Yi Lu ◽  
Xiao-Mei Wu ◽  
Bao-Di Ma ◽  
Yi Xu

Vanillin has many applications in industries. Isoeugenol monooxygenase (IEM) can catalyze the oxidation of isoeugenol to vanillin in the presence of oxygen under mild conditions. However, the low thermal stability of IEM limits its practical application in the biosynthesis of natural vanillin. Herein, two rational strategies were combined to improve the thermostability of IEM from Pseudomonas nitroreducens Jin1. Two variants (K83R and K95R) with better thermostability and one mutant (G398A) with higher activity were identified from twenty candidates based on the Surface Residue Replacement method. According to the Consensus Mutagenesis method, one mutant (I352R) with better thermostability and another mutant (L273F) with higher activity were also identified from nine candidates. After combinatorial mutation, a triple mutant K83R/K95R/L273F with the best thermostability and catalytic efficiency was generated. Compared with the wild-type IEM, the thermal inactivation half-lives (t1/2) of K83R/K95R/L273F at 25 °C, 30 °C, and 35 °C increased 2.9-fold, 11.9-fold, and 24.7-fold, respectively. Simultaneously, it also exhibited a 4.8-fold increase in kcat, leading to a 1.2-fold increase in catalytic efficiency (kcat/Km). When the whole cell of K83R/K95R/L273F was applied to the biotransformation of isoeugenol on preparative scale, the vanillin concentration reached 240.1 mM with space-time yield of 109.6 g/L/d, and vanillin was achieved in 77.6% isolated yield and >99% purity.


Author(s):  
B. L. Soloff ◽  
T. A. Rado

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.


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