Abstract This work studied the effects of ultrasound-assisted liquid-state fermentation on the content of peptides and bioactivity of fermented soybean meal (FSBM) with Bacillus subtilis. Based on the optimization of basic ultrasonic parameters, effects of the main parameters including power density, incubation temperature and ultrasonic time on in vitro ACE inhibitory activity, peptides content and biomass of B. subtilis were investigated via Box-Behnken experimental design. Three mathematical models were determined to show the effects of each variable and their combinatorial interactions on dependent variables. A set of preferred condition was determined to be at power density of 0.08 W/mL for 1 h with an initial incubation temperature of 36.7 °C, according to the desirability function analyses. Under these conditions, the experimental values of in vitro ACE inhibitory activity, peptides content and biomass increased by 26.4%, 36.2% and 55.0% compared to those of the control, respectively, accompanied by the improvement of the peptides yield, purity and conversion rate in varying degrees. Additionally, FSBM resulted in a significant decrease of systolic blood pressure by 20.7 ± 1.8 mmHg in spontaneously hypertensive rats at 3 h. These results suggest that ultrasonication is an efficient solution for enhancing fermentation to produce bioactive components from agroindustrial by-products.

中文翻译：

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用枯草芽孢杆菌超声辅助液态发酵豆粕：对肽含量、ACE 抑制活性和生物量的影响

摘要 本工作研究了超声辅助液态发酵对枯草芽孢杆菌发酵豆粕 (FSBM) 肽含量和生物活性的影响。在优化超声基本参数的基础上，通过Box-Behnken实验设计，研究了功率密度、孵育温度和超声时间等主要参数对枯草芽孢杆菌体外ACE抑制活性、肽含量和生物量的影响。确定了三个数学模型来显示每个变量及其组合相互作用对因变量的影响。根据合意性函数分析，一组优选条件被确定为在 0.08 W/mL 的功率密度下持续 1 小时，初始孵育温度为 36.7 °C。在这些条件下，体外ACE抑制活性、肽含量和生物量的实验值与对照相比分别增加了26.4%、36.2%和55.0%，同时伴随着肽产率、纯度和转化率的不同程度的提高。此外，FSBM 导致自发性高血压大鼠在 3 小时时收缩压显着降低 20.7 ± 1.8 mmHg。这些结果表明，超声波处理是增强发酵以从农工业副产品生产生物活性成分的有效解决方案。FSBM 导致自发性高血压大鼠在 3 小时时收缩压显着降低 20.7 ± 1.8 mmHg。这些结果表明，超声波处理是增强发酵以从农工业副产品生产生物活性成分的有效解决方案。FSBM 导致自发性高血压大鼠在 3 小时时收缩压显着降低 20.7 ± 1.8 mmHg。这些结果表明，超声波处理是增强发酵以从农工业副产品生产生物活性成分的有效解决方案。