scholarly journals Arming Technology in Yeast—Novel Strategy for Whole-cell Biocatalyst and Protein Engineering

Biomolecules ◽  
2013 ◽  
Vol 3 (4) ◽  
pp. 632-650 ◽  
Author(s):  
Kouichi Kuroda ◽  
Mitsuyoshi Ueda
2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Robin Dorau ◽  
Lin Chen ◽  
Jianming Liu ◽  
Peter Ruhdal Jensen ◽  
Christian Solem

Abstract Background Diacetyl provides the buttery aroma in products such as butter and margarine. It can be made via a harsh set of chemical reactions from sugarcane bagasse, however, in dairy products it is normally formed spontaneously from α-acetolactate, a compound generated by selected lactic acid bacteria in the starter culture used. Due to its bacteriostatic properties, it is difficult to achieve high levels of diacetyl by fermentation. Here we present a novel strategy for producing diacetyl based on whole-cell catalysis, which bypasses the toxic effects of diacetyl. Results By expressing a robust α-acetolactate synthase (ALS) in a metabolically optimized Lactococcus lactis strain we obtained a whole-cell biocatalyst that efficiently converted pyruvate into α-acetolactate. After process optimization, we achieved a titer for α-acetolactate of 172 ± 2 mM. Subsequently we used a two-stage production setup, where pyruvate was produced by an engineered L. lactis strain and subsequently used as the substrate for the biocatalyst. Using this approach, 122 ± 5 mM and 113 ± 3 mM α-acetolactate could be made from glucose or lactose in dairy waste, respectively. The whole-cell biocatalyst was robust and fully active in crude fermentation broth containing pyruvate. Conclusions An efficient approach for converting sugar into α-acetolactate, via pyruvate, was developed and tested successfully. Due to the anaerobic conditions used for the biotransformation, little diacetyl was generated, and this allowed for efficient biotransformation of pyruvate into α-acetolactate, with the highest titers reported to date. The use of a two-step procedure for producing α-acetolactate, where non-toxic pyruvate first is formed, and subsequently converted into α-acetolactate, also simplified the process optimization. We conclude that whole cell catalysis is suitable for converting lactose in dairy waste into α-acetolactate, which favors resource utilization.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jinghui Xiong ◽  
Hefeng Chen ◽  
Ran Liu ◽  
Hao Yu ◽  
Min Zhuo ◽  
...  

Abstractε-Caprolactone is a monomer of poly(ε-caprolactone) which has been widely used in tissue engineering due to its biodegradability and biocompatibility. To meet the massive demand for this monomer, an efficient whole-cell biocatalytic approach was constructed to boost the ε-caprolactone production using cyclohexanol as substrate. Combining an alcohol dehydrogenase (ADH) with a cyclohexanone monooxygenase (CHMO) in Escherichia coli, a self-sufficient NADPH-cofactor regeneration system was obtained. Furthermore, some improved variants with the better substrate tolerance and higher catalytic ability to ε-caprolactone production were designed by regulating the ribosome binding sites. The best mutant strain exhibited an ε-caprolactone yield of 0.80 mol/mol using 60 mM cyclohexanol as substrate, while the starting strain only got a conversion of 0.38 mol/mol when 20 mM cyclohexanol was supplemented. The engineered whole-cell biocatalyst was used in four sequential batches to achieve a production of 126 mM ε-caprolactone with a high molar yield of 0.78 mol/mol.


2021 ◽  
Vol 69 (14) ◽  
pp. 4243-4252
Author(s):  
Haixia Xu ◽  
Xiaofeng Li ◽  
Xuan Xin ◽  
Lan Mo ◽  
Yucong Zou ◽  
...  

2014 ◽  
Vol 32 (3) ◽  
pp. 652-662 ◽  
Author(s):  
Chang Sup Kim ◽  
Jeong Hyun Seo ◽  
Dong Gyun Kang ◽  
Hyung Joon Cha

2008 ◽  
Vol 136 ◽  
pp. S385-S386
Author(s):  
Jyh-Ping Chen ◽  
Shu-Chin Chang

2014 ◽  
Vol 107 ◽  
pp. 39-46 ◽  
Author(s):  
Wei-rui Zhao ◽  
Jun Huang ◽  
Chun-long Peng ◽  
Sheng Hu ◽  
Pi-yu Ke ◽  
...  

2012 ◽  
Vol 7 (10) ◽  
pp. 1934578X1200701
Author(s):  
Liangbin Zhou ◽  
Ling Liu ◽  
Tian Tian ◽  
Bailin Xue ◽  
Rongmin Yu

Two new potential antifungal coumarin glycosides, 6-chlorocoumarin 7- O- β-D-glucopyranoside (1) and 7-hydroxy-4-trifluoromethyl-coumarin 5- O- β-D-glucopyranoside (2), were synthesized via enzyme-mediated glycosylation of the respective aglycone, 6-chloro-7-hydroxycoumarin and 5,7-dihydroxy-4-trifluoromethylcoumarin, using transgenic hairy roots of Polygonum multiflorum. Instead of application of the isolated enzyme and exogenous sugar donors, hairy roots of P. multiflorum were successfully adapted as a whole-cell biocatalyst.


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