In this study, the kinetic of lipopeptide biosurfactant production by Bacillus subtilis LAMI005 and its tensoactive and emulsifier properties were evaluated. The influence of the concentrations of nitrogen ((NH₄)₂SO₄) and carbon source (glucose and fructose) on biosurfactant production, using a mineral medium, were evaluated. A production of about 930 mg · L⁻¹ of surfactin was observed for mineral medium supplied with total reducing sugars (16.55 g · L⁻¹) and (NH₄)₂SO₄ (1 g · L⁻¹) as carbon and nitrogen sources, respectively. The crude biosurfactant exhibited its potential as tensoactive, presenting the capability to reach surface tension of about 28 mN ⋅ m⁻¹ for water and exhibiting low CMC (~14–20 mg · L⁻¹). The analysis of emulsifying activity showed a greater stability of emulsion formed in motor oil (3.5 U), soybean oil (2.0 U), and biodiesel (1.5 U). The emulsion formulated on motor oil remained stable for more than 200 h, which was explained by its average drop diameter (~0–10 μm). The surface-active properties of surfactin did not seem to be affected by different NaCl concentrations, which may promote its applicability in high salt environments, such as oil spills in marine areas.

中文翻译：

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枯草芽孢杆菌 LAMI005 生产 surfactin 及其作为表面活性剂和乳化剂的潜力评价

在这项研究中，评估了枯草芽孢杆菌LAMI005 生产脂肽生物表面活性剂的动力学及其张力活性和乳化剂特性。使用矿物培养基评估了氮（(NH ₄ ) ₂ SO ₄）和碳源（葡萄糖和果糖）浓度对生物表面活性剂生产的影响。对于提供总还原糖(16.55 g·L ^-1 )和(NH ₄ ) ₂ SO ₄ (1 g·L ^-1 )的矿物培养基，观察到产生约930mg·L ^{-1的surfactin}) 分别作为碳源和氮源。粗生物表面活性剂表现出其作为张力活性的潜力，表现出对水的表面张力达到约28 mN·m ^-1的能力，并表现出低CMC（~14-20 mg·L ^-1）。乳化活性分析表明，在机油 (3.5 U)、大豆油 (2.0 U) 和生物柴油 (1.5 U) 中形成的乳液具有更高的稳定性。在机油上配制的乳液可保持稳定超过 200 小时，这可以通过其平均液滴直径 (~0-10 μm) 来解释。surfactin 的表面活性特性似乎不受不同 NaCl 浓度的影响，这可能会促进其在高盐环境中的适用性，例如海洋区域的石油泄漏。