Abstract Lipase A exhibits great commercial value due to its applications in the food and paper industry, pharmaceutical chemistry and household chemicals. In this study, we first conducted a comparison of different signal peptides and promoters for the construction of the productive lipase A strain. The maximum extracellular lipase activity was identified as 64.9 U/mL after 12-h fermentation at 37 °C by B. subtilis L25 in which the lipase gene was led by SPlipA and controlled by P43-Phag. Another aim was to determine whether supplementing a culture medium with a combination of glycerol and Streptomyces sp. SCUT-3 digested chicken feather hydrolysates was beneficial to lipase production. Systematic optimization experiments were designed and carried out. Finally, a satisfactory lipase level of 1164.9 U/mL was accomplished in Terrific-Broth medium at a C/N ratio of 0.5 (v/v). This work demonstrates the feasibility of B. subtilis L25 for lipase A industrial production using glycerol and microbes treated chicken feather hydrolysates as inexpensive carbon and nitrogen source.

中文翻译：

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利用廉价底物通过信号肽和启动子筛选实现枯草芽孢杆菌高水平分泌脂肪酶A

摘要 脂肪酶 A 因其在食品和造纸工业、药物化学和家用化学品中的应用而展现出巨大的商业价值。在这项研究中，我们首先对用于构建生产性脂肪酶 A 菌株的不同信号肽和启动子进行了比较。B. subtilis L25 在 37 °C 下发酵 12 小时后，细胞外脂肪酶的最大活性被鉴定为 64.9 U/mL，其中脂肪酶基因由 SPlipA 引导并由 P43-Phag 控制。另一个目的是确定是否用甘油和链霉菌属的组合补充培养基。SCUT-3消化的鸡羽毛水解物有利于脂肪酶的产生。设计并进行了系统的优化实验。最后，令人满意的脂肪酶水平为 1164。在 C/N 比为 0.5 (v/v) 的 Terrific-Broth 培养基中达到 9 U/mL。这项工作证明了 B. subtilis L25 用于脂肪酶 A 工业生产的可行性，使用甘油和微生物处理过的鸡羽毛水解物作为廉价的碳和氮源。