Mathematical simulation of pseudo‐crystallofermentation of hydrocortisone by <i>Arthrobacter simplex</i>

Chen, Kuo-Cheng; Chang, C.; Chiu, Chuang-Fan; Ling, A. C.

doi:10.1002/bit.260270307

Cited by 14 publications

(3 citation statements)

References 9 publications

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“…Furthermore, at the concentrations of 60 g/L and 70 g/L, 92.5% of hydrocortisone was transformed to prednisolone after 3 h. Even about 90% conversion was reached at 80 g/L substrate concentration after 3 h, and the conversion increased slightly to 92.5% at 6 h. Longer duration of the process did not lead to a more complete conversion of the hydrocortisone. The remaining hydrocortisone was probably trapped in mixed crystals with prednisolone during the reaction, thereby decreasing its availability for reaction [ 39 , 40 , 41 ].…”

Section: Resultsmentioning

confidence: 99%

A New 3-Ketosteroid-Δ1–Dehydrogenase with High Activity and Broad Substrate Scope for Efficient Transformation of Hydrocortisone at High Substrate Concentration

et al. 2022

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3-Ketosteroid-Δ1-dehydrogenases (KstDs [EC 1.3.99.4]) catalyze the Δ1-dehydrogenation of steroids and are a class of important enzymes for steroid biotransformations. In this study, nine putative kstD genes from different origins were selected and overexpressed in Escherichia coli BL21(DE3). These recombinant enzymes catalyzed the Δ1-desaturation of a variety of steroidal compounds. Among them, the KstD from Propionibacterium sp. (PrKstD) displayed the highest specific activity and broad substrate spectrum. The detailed catalytic characterization of PrKstD showed that it can convert a wide range of 3-ketosteroid compounds with diverse substituents, ranging from substituents at the C9, C10, C11 and C17 position through substrates without C4-C5 double bond, to previously inactive C6-substituted ones such as 11β,17-dihydroxy-6α-methyl-pregn-4-ene-3,20-dione. Reaction conditions were optimized for the biotransformation of hydrocortisone in terms of pH, temperature, co-solvent and electron acceptor. By using 50 g/L wet resting E. coli cells harboring PrKstD enzyme, the conversion of hydrocortisone was about 92.5% within 6 h at the substrate concentration of 80 g/L, much higher than the previously reported results, demonstrating the application potential of this new KstD.

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Section: Resultsmentioning

confidence: 99%

A New 3-Ketosteroid-Δ1–Dehydrogenase with High Activity and Broad Substrate Scope for Efficient Transformation of Hydrocortisone at High Substrate Concentration

et al. 2022

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“…The histogram also shows that the conversion percentage measured at 30, 40, and 50 mg/50 mL medium at 24 hours becomes lower (48.13, 10.94, and 6.43%) compared with the conversion percentage measured at 10 and 20 mg at the same time (58.33 and 50.49%), respectively. This is due to that the higher concentration of substrate may block the pores of the hydrogel and also hinder the exchange of oxygen and substrate diffusion through the hydrogel [2, 22, 23, 24]. In general, the conversion percentages measured at 10, 20, 30, 40, and 50 mg/50 mL medium at 18 hours were higher than those obtained at 24 hours.…”

Section: Resultsmentioning

confidence: 99%

Production of Prednisolone by Pseudomonas oleovorans Cells Incorporated Into PVP/PEO Radiation Crosslinked Hydrogels

El-Hady

El‐Rehim

2004

BioMed Research International

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In order to rise the yield of prednisolone from hydrocortisone, the Pseudomonas oleovorans cells were entrapped into radiation crosslinked poly (vinyl pyrrolidone)/poly(ethylene oxide) (PVP/PEO) hydrogel of different gel contents. The factors affecting the gel content and swelling behavior of the polymeric gel, such as polymer composition, polymer blend concentration, and irradiation doses, were investigated. The formation of gels having a good strength with the ability to retain a desirable amount of water in their three-dimensional network can be achieved by using PVP/PEO copolymer of composition (90 : 10) and concentration of 15% prepared at 20 kGy irradiation dose. At these conditions the prepared hydrogel is considered the most favorable one that gave the highest hydrocortisone bioconversion and prednisolone yield, 81% and 62.8%, respectively. The improvement of prednisolone yield was also achieved by increasing substrate concentration. Maximum hydrocortisone bioconversion (86.44) was obtained at 18 hours by using substrate concentration of 30 mg. Reusability of immobilized Pseudomonas oleovorans entrapped into PVP/PEO copolymer hydrogel was studied. The results indicated that the transformation capacity of hydrocortisone to prednisolone highly increased by the repeated use of copolymer for 4 times. This was accompanied by an increase in prednisolone yield to 89% and the bioconversion of hydrocortisone was 98.8%.

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“…The area ratio of the two spots was determined with the aid of a 254-nm UV analyzer. The area ratio determined corresponded to a known weight ratio of product to total steroids (Boeren et al, 1987;Chen et al, 1985).…”

Section: Determination Of Conversion Ratementioning

confidence: 99%

Strain selection of Metarrhizium anisopliae by image analysis of colony morphology for consistency of steroid biotransformation

Yang

Wang

et al. 2001

Biotech & Bioengineering

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Quantitative description of colony morphological images of the fungus Metarrhizium anisopliae was done by means of computer image analysis based on fractal analysis. Compared with simple fractal analysis, the differences in the morphological features of colonies were expressed more accurately by multifractal analysis. The use of multifractal analysis markedly improved the reliability of colony image analysis, which could be extended to morphological characterization for colony recognition and classification. First, the multifractal spectrum was calculated from each morphological image and 14 features were defined on the spectrum to describe the spectral line profile. Second, three features, alpha-right, alpha-width, and f-start, were selected from the 14 features in two-dimensional feature vector spaces and a feature augmented vector (alpha-right, alpha-width, and f-start, 1)(T) was generated and used for classifier design. Third, a statistical least mean square error (LMSE) algorithm was applied to design a piecewise-linear classifier, which consists of two linear classifiers, d(1)(x) and d(2)(x). Representative colony samples were used as training and test sample sets, which were previously classified into a high-activity class and another class by a training person. After passing the training phase, the piecewise-linear classifier could be used for automated classification of unknown colony samples. A correct recognition rate of 96% was achieved in this manner. Compared with conventional strain selection methods, this new method has the advantage of less subjectivity, reduced labor and time, and improved ability to deal with a large number of colonies.

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Mathematical simulation of pseudo‐crystallofermentation of hydrocortisone by Arthrobacter simplex

Cited by 14 publications

References 9 publications

A New 3-Ketosteroid-Δ1–Dehydrogenase with High Activity and Broad Substrate Scope for Efficient Transformation of Hydrocortisone at High Substrate Concentration

A New 3-Ketosteroid-Δ1–Dehydrogenase with High Activity and Broad Substrate Scope for Efficient Transformation of Hydrocortisone at High Substrate Concentration

Production of Prednisolone by Pseudomonas oleovorans Cells Incorporated Into PVP/PEO Radiation Crosslinked Hydrogels

Strain selection of Metarrhizium anisopliae by image analysis of colony morphology for consistency of steroid biotransformation

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