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1.
Biotechnol Bioeng ; 120(6): 1521-1530, 2023 06.
Article in English | MEDLINE | ID: mdl-36799475

ABSTRACT

Carbonyl reductase (CR)-catalyzed bioreduction in the organic phase and the neat substrate reaction system is a lasting challenge, placing higher requirements on the performance of enzymes. Protein engineering is an effective method to enhance the properties of enzymes for industrial applications. In the present work, a single point mutation E145A on our previously constructed CR mutant LsCRM3 , coevolved thermostability, and activity. Compared with LsCRM3 , the catalytic efficiency kcat /KM of LsCRM3 -E145A (LsCRM4 ) was increased from 6.6 to 21.9 s-1 mM-1 . Moreover, E145A prolonged the half-life t1/2 at 40°C from 4.1 to 117 h, T m ${T}_{m}$ was increased by 5°C, T 50 30 ${T}_{50}^{30}$ was increased by 14.6°C, and Topt was increased by 15°C. Only 1 g/L of lyophilized Escherichia coli cells expressing LsCRM4 completely reduced up to 600 g/L 2-chloro-1-(3,4-difluorophenyl)ethanone (CFPO) within 13 h at 45°C, yielding the corresponding (1S)-2-chloro-1-(3,4-difluorophenyl)ethanol ((S)-CFPL) in 99.5% eeP , with a space-time yield of 1.0 kg/L d, the substrate to catalyst ratios (S/C) of 600 g/g. Compared with LsCRM3 , the substrate loading was increased by 50%, with the S/C increased by 14 times. Compared with LsCRWT , the substrate loading was increased by 6.5 times. In contrast, LsCRM4 completely converted 600 g/L CFPO within 12 h in the neat substrate bioreaction system.


Subject(s)
Point Mutation , Protein Engineering , Catalysis , Ethanol , Substrate Specificity
2.
Int J Biol Macromol ; 274(Pt 1): 133264, 2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38901517

ABSTRACT

Chiral alcohols are essential building blocks of numerous pharmaceuticals and fine chemicals. Aldo-keto reductases (AKRs) constitute a superfamily of oxidoreductases that catalyze the reduction of aldehydes and ketones to their corresponding alcohols using NAD(P)H as a coenzyme. Knowledge about the crucial roles of AKRs immobilization in the biocatalytic synthesis of chiral alcohols is expanding. Herein, we reviewed the characteristics of various AKRs immobilization approaches, the applications of different immobilization materials, and the prospects of continuous flow bioreactor construction by employing these immobilized biocatalysts for synthesizing chiral alcohols. Finally, the opportunities and ongoing challenges for AKR immobilization are discussed and the outlook for this emerging area is analyzed.

3.
Sci Prog ; 106(1): 368504221148003, 2023.
Article in English | MEDLINE | ID: mdl-36617875

ABSTRACT

Energy is becoming more and more important in the process of development. Through cluster analysis, 30 provinces chosen from the Chinese mainland are divided into high, medium, and low energy consumption regions, and the Theil index is used to analyze the characteristics of total energy consumption and other characteristics of regional differences. Based on this, an enhanced Panel-STIRPAT model is constructed. Through data and model inspection, panel models suitable for each region are selected for comprehensive analysis. The results show that: there are regional differences in energy consumption in China, and the total regional differences mainly come from within each region. The factors affecting energy consumption in different regions are the same, but due to differences in geographical environment and stress levels, the influence of these factors on energy consumption in different regions is different. Based on this, reasonable measurements to control energy consumption in different regions are presented.


Subject(s)
Conservation of Energy Resources , China
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