Kinetic analysis and modeling of the liquid–liquid conversion of emulsified di‐rhamnolipids by Naringinase from Penicillium decumbens
Kinetic analysis and modeling of the liquid–liquid conversion of emulsified di‐rhamnolipids by Naringinase from Penicillium decumbens
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斜卧青霉柚皮苷酶乳化二鼠李糖脂液-液转化的动力学分析和建模
DOI：
10.1002/bit.22057
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发表时间：
2009
影响因子：
3.8
通讯作者：
C. Syldatk
中科院分区：
文献类型：
--
作者：
I. Magario;O. Vielhauer;Anke Neumann;Rudolf Hausmann;C. Syldatk
对聚集体形成底物的酶促转化进行动力学分析，并应用模型预测反应时间过程。来自二鼠李糖脂的L-鼠李糖分子被来自斜卧青霉的柚苷酶裂解，产生单鼠李糖脂。当底物和产物在微酸性水相中形成大的共聚集体时，发现最佳反应速率。另一方面，反应速率与初始二鼠李糖脂浓度无关，这是通过假设反应发生在水相中（根据Michaelis-Menten动力学）并结合竞争性L-鼠李糖抑制来解释的。因此，假定鼠李糖脂高度浓缩在聚集体（第二液相）中，而由于酶促反应，发生从水相和向水相的扩散性鼠李糖脂转运。此外，假设二和单鼠李糖脂之间的理想表面活性剂混合用于解释后者对反应速率的负面影响。创建了相应描述系统的模型。实验数据的比较，与预测值非常吻合。本研究的结果可有益地适用于涉及由亲水性酶催化的聚集体形成底物和/或产物的任何生物转化。Biotechnol. Bioeng. 2009;102：9-19.© 2008 Wiley Periodicals，Inc.
The enzymatic conversion of an aggregate‐forming substrate was kinetically analyzed and a model was applied for the prediction of reaction‐time courses. An L‐rhamnose molecule from a di‐rhamnolipid is cleaved by Naringinase from Penicillium decumbens leading to a mono‐rhamnolipid. Optimal reaction rates were found when both, substrate and product build large co‐aggregates in a slightly acidic aqueous phase. On the other hand, reaction rates were independent of initial di‐rhamnolipid concentration and this was interpreted by assuming that the reaction occurs in the aqueous phase according to Michaelis–Menten kinetics in combination with competitive L‐rhamnose inhibition. Rhamnolipids were therefore assumed to be highly concentrated in aggregates, a second liquid phase, whereas diffusive rhamnolipid transport from and to the aqueous phase occurs due to the enzymatic reaction. Furthermore, ideal surfactant mixing between di‐ and mono‐rhamnolipid was assumed for interpretation of the negative effect of the last on the reaction rate. A model was created that describes the system accordingly. The comparison of the experimental data, were in excellent agreement with the predicted values. The findings of this study may beneficially be adapted for any bioconversion involving aggregate‐forming substrate and/or product being catalyzed by hydrophilic enzymes. Biotechnol. Bioeng. 2009;102: 9–19. © 2008 Wiley Periodicals, Inc.