The hydrolytic and cost efficiencies of five endopeptidases (Alcalase 2.4L, Corolase 7089, Neutrase 0.8L, Promod 671L and Protex 7L) to hydrolyze Atlantic salmon by-products were compared at standardized activity levels based on a casein assay. The substrate was characterized prior to the hydrolytic experiments (pH=6.5, t=50 °C) to obtain substrate--specific constants for nitrogen to protein mass (in g) ratio, i.e. conversion factor f_N=5.23 and total amount of peptide bonds (h_tot)=9.3 mmol per g of protein. At low enzyme activity to substrate ratio, all enzymes were equally efficient in hydrolyzing the substrate. At highest enzyme activity to substrate ratio, Protex 7L, Alcalase 2.4L and Promod 671L gave higher degree of hydrolysis (DH=14.2-14.6%) than Corolase 7089 (13.2%) and Neutrase 0.8L (11.6%) after 120 min of hydrolysis. No differences were observed in protein recovery (yield of solubilized protein) relative to DH. Determination of DH was followed by the pH-STAT and o-phthaldialdehyde methods. Based on pH-STAT data, response surface regression models were established based on the combined effects of hydrolysis time and enzyme activity to substrate ratio on DH and protein recovery. The modelling approach was combined with enzyme cost to identify the most cost-efficient enzyme (Protex 7L).

中文翻译：

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一种比较内肽酶水解大西洋鲑鱼（Salmo salar）副产物的成本效率的系统方法。

根据酪蛋白分析，比较了五个内肽酶（Alcalase 2.4L，Corolase 7089，Neutrase 0.8L，Promod 671L和Protex 7L）水解大西洋鲑鱼副产物的水解和成本效率。在水解实验（pH = 6.5，t = 50°C）之前对底物进行表征，以获得氮与蛋白质质量（单位：g）之比的底物特定常数，即转化因子f _N = 5.23和肽总量键（ħ_托特）= 9.3 mmol / g蛋白质。在酶活性与底物比率低的情况下，所有酶在水解底物方面都同样有效。在最高的酶活性与底物比率下，水解120分钟后，Protex 7L，Alcalase 2.4L和Promod 671L的水解度（DH = 14.2-14.6％）高于Corolase 7089（13.2％）和Neutrase 0.8L（11.6％）。 。相对于DH，在蛋白质回收率（增溶蛋白质的产量）方面未观察到差异。DH的测定随后是pH-STAT和o-邻苯二甲醛法。基于pH-STAT数据，基于水解时间和酶活性/底物比对DH和蛋白质回收率的综合影响，建立了响应面回归模型。建模方法与酶的成本相结合，以鉴定出最具成本效益的酶（Protex 7L）。