Abstract This study evaluated coupled effects of molar ratio of substrates and enzyme loading in a solvent-free system using a simple mathematical approach to obtain high conversions on octyl caprylate synthesis with Novozym 435. When molar ratios of caprylic acid to n-octanol (1:1 and 1:3) were evaluated with enzyme loadings of 1% to 4% (wt/wt acid), an interdependence between the masses of reagents and the enzymes was observed, that was expressed as a mathematical relation. The study of this relation, named as SER, indicated a specific range of reaction conditions that resulted in conversions above 90%. The most suitable condition corresponded to an acid:alcohol molar ratio of 1:1.3 and an enzyme loading of 1.5%, resulting in 94.5% of conversion at 65 °C in 3 hours of reaction. A different reaction system (bottle reactor) was used to evaluate the influence of reagents mixture and heat distribution. The use of a bottle reactor allowed yield improvement that reached 99.3%. At this condition, Novozym 435 was reused, without washing steps, in three subsequent batches keeping high conversion. A possible balance between the shift of chemical equilibrium by stoichiometric excess of reagents and enzymatic inhibition effects by substrates can be expressed mathematically in a convenient way, helping to predict the behaviour of synthesis in different conditions. The mathematical relation proposed, SER, allowed the achievement of 99% of conversion on enzymatic synthesis of octyl caprylate.

中文翻译：

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使用 Novozym 435 获得高产脂肪酶介导的辛酸辛酯合成的实用方法

摘要 本研究使用简单的数学方法评估了无溶剂系统中底物摩尔比和酶负载量的耦合效应，以在 Novozym 435 合成辛酸辛酯中获得高转化率。当辛酸与正辛醇的摩尔比 (1: 1 和 1:3) 用 1% 到 4% (wt/wt 酸) 的酶负载进行评估，观察到试剂质量和酶之间的相互依赖性，这表示为数学关系。对这种关系的研究，称为 SER，表明导致转化率高于 90% 的特定反应条件范围。最合适的条件对应于 1:1.3 的酸:醇摩尔比和 1.5% 的酶加载量，在 65 °C 下反应 3 小时，转化率为 94.5%。使用不同的反应系统（瓶式反应器）来评估试剂混合物和热分布的影响。瓶式反应器的使用使产量提高了 99.3%。在此条件下，Novozym 435 在三个后续批次中重复使用，无需洗涤步骤，保持高转化率。化学计量过量的试剂引起的化学平衡移动和底物的酶抑制作用之间可能的平衡可以用一种方便的方式在数学上表达，有助于预测不同条件下的合成行为。提出的数学关系 SER 允许在辛酸辛酯的酶促合成中实现 99% 的转化率。Novozym 435 在三个后续批次中重复使用，无需洗涤步骤，保持高转化率。化学计量过量的试剂引起的化学平衡移动和底物的酶抑制作用之间可能的平衡可以用一种方便的方式在数学上表达，有助于预测不同条件下的合成行为。提出的数学关系 SER 允许在辛酸辛酯的酶促合成中实现 99% 的转化率。Novozym 435 在三个后续批次中重复使用，无需洗涤步骤，保持高转化率。化学计量过量的试剂引起的化学平衡移动和底物的酶抑制作用之间可能的平衡可以用一种方便的方式在数学上表达，有助于预测不同条件下的合成行为。提出的数学关系 SER 允许在辛酸辛酯的酶促合成中实现 99% 的转化率。有助于预测不同条件下的合成行为。提出的数学关系 SER 允许在辛酸辛酯的酶促合成中实现 99% 的转化率。有助于预测不同条件下的合成行为。提出的数学关系 SER 允许在辛酸辛酯的酶促合成中实现 99% 的转化率。