FOOD CHEMISTRY
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2022
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IF 9.231
Yongxin Su,Zhenlin Li,Yinghui Zhao,Yijun Chen,Chen Luo,Xuri Wu
Extracts of Siraitia grosvenorii (Swingle), in Chinese known as Luo Han Guo (LHG), is authorized for use as a natural sweetener . LHG is rich in mogroside V that contains five glucoses, but also contains mogroside IIIE and analogues with fewer than three glucose units that cause an unpleasant aftertaste, limiting the use of the extract. Snailase was applied here to convert mogroside V in LHG extract in favor of siamenoside I formation, the sweetest mogroside with a taste similar to sucrose . For application, snailase was immobilized by adsorption to NKA (a macroporous resin), resulting in 10.9 U per g of adsorbed protein. Reuse of the NKA-adsorbed snailase was demonstrated for four cycles, and a continuous production of improved LHG extract at a 0.5 L scale had a productivity of 68.4 g/(L⋅day). The resulting product containing over 50% siamenoside I displayed an improved taste profile with satisfying safety toward HEK293T cells.
研究领域:
食品科学
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生物化学
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生物技术
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DOI
PubMed
高影响因子
Chemistry Africa-A Journal of the Tunisian Chemical Society
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2025
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IF 2.2
Chen Wang,Zhang Fen,Xu Jianghe,Lai Feifan
Purpose To immobilize snailase on SBA-15 to enhance the efficient conversion of Epimedium wushanense extracts for the preparation of rhamnosyl icariside II. Methods The snailase was covalently coupled to amino and aldehyde modified SBA-15, and the immobilization conditions were optimized. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), N 2 adsorption-desorption analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the physicochemical properties of immobilized snailase. The optimal enzymatic hydrolysis conditions, enzymatic kinetic parameters, storage stability and reusability of the immobilized snailase were investigated. Results The optimal immobilization conditions were pH 5.0, temperature 30℃, immobilization time 3 h and snailase concentration 10 mg⋅mL − 1 . The immobilized snailase showed a retained activity of 235.8 µmol⋅(h⋅g) −1 and a high enzyme loading capacity of 249.6 mg⋅g − 1 support. The optimum hydrolysis conditions for immobilized snailase were pH 5.5, temperature 50℃, substrate concentration 3.0 mg⋅mL − 1 , and reaction time 6 h. The V max and K m of the immobilized snailase were 3.92 µg⋅min − 1 and 1.18 mmol⋅L − 1 , respectively. Conclusion The immobilized snailase has a high enzyme loading capacity, strong conversion capability, better storage stability and good reusability, making it suitable for the efficient conversion of Epimedium wushanense extracts to produce rhamnosyl icariside II.
研究领域:
酶学
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生物催化
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植物化学
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纳米技术
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生物技术
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DOI
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
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2023
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IF 3.4
Yinghui Zhao,Yongxin Su,Zhenlin Li,Chen Luo,Yijun Chen,Xuri Wu
To solve the insufficient availability of mogrol, an 11α-hydroxy aglycone of mogrosides in Siraitia grosvenorii , snailase was employed as the enzyme to completely deglycosylate LHG extract containing 50% mogroside V. Other commonly used glycosidases performed less efficiently. Response surface methodology was conducted to optimize the productivity of mogrol, which peaked at 74.7% in an aqueous reaction. In view of the differences in water-solubility between mogrol and LHG extract, we employed an aqueous-organic system for the snailase-catalyzed reaction. Of five tested organic solvents , toluene performed best and was relatively well tolerated by snailase. After optimization, biphasic medium containing 30% toluene (v/v) could produce a high-quality mogrol (98.1% purity) at a 0.5 L scale with a production rate of 93.2% within 20 h. This toluene-aqueous biphasic system would not only provide sufficient mogrol to construct future synthetic biology systems for the preparation of mogrosides, but also facilitate the development of mogrol-based medicines.
研究领域:
生物化学
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生物技术
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药学
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DOI
PubMed
高影响因子
JOURNAL OF APPLIED MICROBIOLOGY
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2017
·Vol. 124
·期 2
·469-479
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IF 2.099
T. Cheng,X. Xu,W. Zhang,L. Chen,T. Liu
Aims To establish a proper protoplast-preparation route from enriched motile flagellates and nonmotile resting cells of Haematococcus pluvialis . Methods and Results Through cultivations in two mixotrophic media, enriched Haematococcus flagellates and resting cells were respectively produced and applied in enzymatic protoplast preparations. Great differences of enzymatic sensitivity and osmotic-lability were identified between them. Flagellates showed the same osmotic-lability as protoplasts and the extracellular matrix-removing rate was applied for an evaluation of protoplast-releasing. During the treatment of flagellates, an addition of more than 0·2 mmol l −1 Ca 2+ was found to be essential for maintenance of high cellular viability. More than 80% cellular viability and a 90% protoplast-releasing rate were obtained simultaneously after 2–3 h treatment of 0·06% proteinase K in 0·05 mol l −1 Tris-HCl (pH7·8) buffer with 0·2 mmol l −1 CaCl 2 and 0·2 mol l −1 sorbitol/mannitol. For resting cells, a treatment of both 0·12% proteinase K and a combination of 2% cellulase + 1% snailase could function similarly in order to degrade the cellulosic cell wall, while the protoplast yield was limited to about 40%, due to the existence of an undegradable secondary wall in the mature resting cell. Conclusion Proteinase K was efficient for protoplast-releasing from either flagellates or resting cells. Due to the great difference of enzymatic sensitivity and osmotic-lability between flagellates and resting cells, it was necessary to select a different enzymatic treating process based upon the main cell type in the culture. A better protoplast-preparing efficiency was obtained from Haematococcus cells when flagellates were in the majority. Significance and Impact of the Study The protoplast preparation of H. pluvialis was firstly established based on two main cell types of H. pluvialis , motile flagellates and nonmotile resting cells. Increase of flagellate stability and viable protoplast-preparing efficiency through addition of Ca 2+ in enzymatic solution was firstly reported.
研究领域:
微生物学
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生物技术
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植物科学
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DOI
PubMed
高影响因子
BULLETIN OF MATERIALS SCIENCE
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2019
·Vol. 42
·期 1
·1-7
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IF 1.264
Hassan Mohamed,Ran Xiaoku,Yuan Ying,Luan Xiaoning,Dou De-Qiang
Ginsenoside transformation has received significant attention from scientists. The main objective of this study is to use immobilized enzymes in ginsenoside transformation. Factors affecting immobilization process were studied; carrageenan beads treated with polyethyleneimine and then activated using glutaraldehyde (GA) were used for snailase enzyme immobilization. The functionalized gel beads were characterized using Fourier transform infrared spectroscopy to verify the modification process. Furthermore, the optimum conditions for biotransformation of ginsenoside were also deliberated and showed that optimum biotransformation pH is 4.5 and 5–5.5 and temperature 50 and \(60^{\circ }\hbox {C}\) for free and immobilized snailase, respectively. Michaelis constants, \(K_{\mathrm{m}}\) and \(V_{\max }\) , were also studied. The immobilized enzyme retains 96% of its initial activity after being used 10 consecutive times. The results clearly suggested that ginsenoside transformation was performed using immobilized snailase; this process can reduce the transformation cost as the enzyme can be reused many times.
研究领域:
生物技术
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药学
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酶学
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DOI
高影响因子
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