scholarly journals A Novel 3-Phytosterone-9α-Hydroxylase Oxygenation Component and Its Application in Bioconversion of 4-Androstene-3,17-Dione to 9α-Hydroxy-4-Androstene-3,17-Dione Coupling with A NADH Regeneration Formate Dehydrogenase

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2534 ◽  
Author(s):  
Xian Zhang ◽  
Manchi Zhu ◽  
Rumeng Han ◽  
Youxi Zhao ◽  
Kewei Chen ◽  
...  
Keyword(s):  
Formate Dehydrogenase ◽  
Batch Process ◽  
Regeneration System ◽  
Optimum Ratio ◽  
Fed Batch ◽  
Nadh Regeneration ◽  
Key Enzyme ◽  
Biological Transformation ◽  
Economical Process

9α-Hydroxy-4-androstene-3,17-dione (9-OH-AD) is one of the significant intermediates for the preparation of β-methasone, dexamethasone, and other steroids. In general, the key enzyme that enables the biotransformation of 4-androstene-3,17-dione (AD) to 9-OH-AD is 3-phytosterone-9α-hydroxylase (KSH), which consists of two components: a terminal oxygenase (KshA) and ferredoxin reductase (KshB). The reaction is carried out with the concomitant oxidation of NADH to NAD+. In this study, the more efficient 3-phytosterone-9α-hydroxylase oxygenase (KshC) from the Mycobacterium sp. strain VKM Ac-1817D was confirmed and compared with reported KshA. To evaluate the function of KshC on the bioconversion of AD to 9-OH-AD, the characterization of KshC and the compounded system of KshB, KshC, and NADH was constructed. The optimum ratio of KSH oxygenase to reductase content was 1.5:1. An NADH regeneration system was designed by introducing a formate dehydrogenase, further confirming that a more economical process for biological transformation from AD to 9-OH-AD was established. A total of 7.78 g of 9-OH-AD per liter was achieved through a fed-batch process with a 92.11% conversion rate (mol/mol). This enzyme-mediated hydroxylation method provides an environmentally friendly and economical strategy for the production of 9-OH-AD.

Characterization of a recombinant antibody produced in the course of a high yield fed-batch process

1994 ◽  
Vol 44 (6) ◽  
pp. 727-735 ◽  
Author(s):  
D. K. Robinson ◽  
C. P. Chan ◽  
C. Yu Lp ◽  
P. K. Tsai ◽  
J. Tung ◽  
...  
Keyword(s):  
Recombinant Antibody ◽  
Batch Process ◽  
High Yield ◽  
Fed Batch

scholarly journals Efficient 2,3-Butanediol/Acetoin Production Using Whole-Cell Biocatalyst with a New Nadh/Nad(+) Regeneration System

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1422
Author(s):  
Yaping Wang ◽  
Yanhong Peng ◽  
Xiaoyan Liu ◽  
Ronghua Zhou ◽  
Xianqing Liao ◽  
...  
Keyword(s):  
Formate Dehydrogenase ◽  
Target Genes ◽  
Nadh Oxidase ◽  
Expression System ◽  
Regeneration System ◽  
Nadh Regeneration ◽  
Whole Cell ◽  
Whole Cell Biocatalyst ◽  
Acetoin Production ◽  
Butanediol Dehydrogenase

An auto-inducing expression system was developed that could express target genes in S. marcescens MG1. Using this system, MG1 was constructed as a whole-cell biocatalyst to produce 2,3-butanediol/acetoin. Formate dehydrogenase (FDH) and 2,3-butanediol dehydrogenase were expressed together to build an NADH regeneration system to transform diacetyl to 2,3-butanediol. After fermentation, the extract of recombinant S. marcescens MG1ABC (pETDuet-bdhA-fdh) showed 2,3-BDH activity of 57.8 U/mg and FDH activity of 0.5 U/mg. And 27.95 g/L of 2,3-BD was achieved with a productivity of 4.66 g/Lh using engineered S. marcescens MG1(Pswnb+pETDuet-bdhA-fdh) after 6 h incubation. Next, to produce 2,3-butanediol from acetoin, NADH oxidase and 2,3-butanediol dehydrogenase from Bacillus subtilis were co-expressed to obtain a NAD+ regeneration system. After fermentation, the recombinant strain S. marcescens MG1ABC (pSWNB+pETDuet-bdhA-yodC) showed AR activity of 212.4 U/mg and NOX activity of 150.1 U/mg. We obtained 44.9 g/L of acetoin with a productivity of 3.74 g/Lh using S. marcescens MG1ABC (pSWNB+pETDuet-bdhA-yodC). This work confirmed that S. marcescens could be designed as a whole-cell biocatalyst for 2,3-butanediol and acetoin production.

scholarly journals Purification and Characterization of a Novel Alcohol Dehydrogenase from Leifsonia sp. Strain S749: a Promising Biocatalyst for an Asymmetric Hydrogen Transfer Bioreduction

2005 ◽  
Vol 71 (7) ◽  
pp. 3633-3641 ◽  
Author(s):  
Kousuke Inoue ◽  
Yoshihide Makino ◽  
Nobuya Itoh
Keyword(s):  
Molecular Weight ◽  
Alcohol Dehydrogenase ◽  
Hydrogen Transfer ◽  
Soil Samples ◽  
Hydrogen Donor ◽  
Regeneration System ◽  
Purification And Characterization ◽  
Nadh Regeneration ◽  
Aldehydes And Ketones

ABSTRACT To find microorganisms that could reduce phenyl trifluoromethyl ketone (PTK) to (S)-1-phenyltrifluoroethanol [(S)-PTE], styrene-assimilating bacteria (ca. 900 strains) isolated from soil samples were screened. We found that Leifsonia sp. strain S749 was the most suitable strain for the conversion of PTK to (S)-PTE in the presence of 2-propanol as a hydrogen donor. The enzyme corresponding to the reaction was purified homogeneity, characterized and designated Leifsonia alcohol dehydrogenase (LSADH). The purified enzyme had a molecular weight of 110,000 and was composed of four identical subunits (molecular weight, 26,000). LSADH required NADH as a cofactor, showed little activity with NADPH, and reduced a wide variety of aldehydes and ketones. LSADH catalyzed the enantioselective reduction of some ketones with high enantiomeric excesses (e.e.): PTK to (S)-PTE (>99% e.e.), acetophenone to (R)-1-phenylethanol (99% e.e.), and 2-heptanone to (R)-2-heptanol (>99% e.e.) in the presence of 2-propanol without an additional NADH regeneration system. Therefore, it would be a useful biocatalyst.

Production of Rhamnolipid Biosurfactant from Fed Batch Culture by Pseudomonas aeruginosa using Multiple Substrates

2020 ◽  
Vol 16 (6) ◽  
pp. 928-933
Author(s):  
Jujjavarapu S. Eswari
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Batch Process ◽  
Time Interval ◽  
Fed Batch ◽  
Multiple Substrates ◽  
Surface Active Agents ◽  
Limiting Nutrients ◽  
Limiting Nutrient ◽  
Surface Active ◽  
Rhamnolipid Biosurfactant

Objective: Biosurfactants are the surface active agents which are used for the reduction of surface and interfacial tensions of liquids. Rhamnolipids are the surfactants produced by Pseudomonas aeruginosa. It requires minimum nutrition for its growth as it can also grow in distilled water. The rhamnolipids produced by Pseudomonas aeruginosa are extra-cellular glycolipids consisting of L-rhamnose and 3-hydroxyalkanoic acid. Methods: The fed-batch method for the rhamnolipid production is considered in this study to know the influence of the carbon, nitrogen, phosphorous substrates as growth-limiting nutrients. Pulse feeding is employed for limiting nutrient addition at particular time interval to obtain maximum rhamnolipid formation from Pseudomonas aeruginosa compared with the batch process. Results: Out of 3 fed batch strategies constant glucose fed batch strategy shows best and gave maximum rhamnolipid concentration of 0.134 g/l.

Molecular cloning and functional characterization of CvLCYE, a key enzyme in lutein synthesis pathway in Chlorella vulgaris

2021 ◽  
Vol 55 ◽  
pp. 102246
Author(s):  
Sulin Lou ◽  
Xin Lin ◽  
Chenglong Liu ◽  
Muhammad Anwar ◽  
Hui Li ◽  
...  
Keyword(s):  
Molecular Cloning ◽  
Chlorella Vulgaris ◽  
Functional Characterization ◽  
Key Enzyme

scholarly journals Purification and characterization of eucaryotic alanine racemase acting as key enzyme in cyclosporin biosynthesis.

1994 ◽  
Vol 269 (17) ◽  
pp. 12710-12714
Author(s):  
K. Hoffmann ◽  
E. Schneider-Scherzer ◽  
H. Kleinkauf ◽  
R. Zocher
Keyword(s):  
Alanine Racemase ◽  
Purification And Characterization ◽  
Key Enzyme
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