Laboratório de Microbiologia Aplicada, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, C.P. 486, Belo Horizonte, MG, 31270-901, Brazil.
Laboratório de Microbiologia Aplicada, Universidade CEUMA, R. Josué Montello, 01, São Luís, MA, 65075120, Brazil.
Microb Cell Fact. 2017 Sep 19;16(1):155. doi: 10.1186/s12934-017-0769-7.
Lactobacillus species produce biosurfactants that can contribute to the bacteria's ability to prevent microbial infections associated with urogenital and gastrointestinal tracts and the skin. Here, we described the biological and physicochemical properties of biosurfactants produced by Lactobacillus jensenii P and Lactobacillus gasseri P.
The biosurfactants produced by L. jensenii P and L. gasseri P reduced the water surface tension from 72 to 43.2 mN m and 42.5 mN m as their concentration increased up to the critical micelle concentration (CMC) values of 7.1 and 8.58 mg mL, respectively. Maximum emulsifying activity was obtained at concentrations of 1 and 5 mg mL for the P and P strains, respectively. The Fourier transform infrared spectroscopy data revealed that the biomolecules consist of a mixture of carbohydrates, lipids and proteins. The gas chromatography-mass spectrum analysis of L. jensenii P biosurfactant showed a major peak for 14-methypentadecanoic acid, which was the main fatty acid present in the biomolecule; conversely, eicosanoic acid dominated the biosurfactant produced by L. gasseri P. Although both biosurfactants contain different percentages of the sugars galactose, glucose and ribose; rhamnose was only detected in the biomolecule produced by L. jensenii P. Emulsifying activities were stable after a 60-min incubation at 100 °C, at pH 2-10, and after the addition of potassium chloride and sodium bicarbonate, but not in the presence of sodium chloride. The biomolecules showed antimicrobial activity against clinical isolates of Escherichia coli and Candida albicans, with MIC values of 16 µg mL, and against Staphylococcus saprophyticus, Enterobacter aerogenes and Klebsiella pneumoniae at 128 µg mL. The biosurfactants also disrupted preformed biofilms of microorganisms at varying concentrations, being more efficient against E. aerogenes (64%) (P biosurfactant), and E. coli (46.4%) and S. saprophyticus (39%) (P biosurfactant). Both strains of lactobacilli could also co-aggregate pathogens.
This report presents the first characterization of biosurfactants produced by L. jensenii P and L. gasseri P. The antimicrobial properties and stability of these biomolecules indicate their potential use as alternative antimicrobial agents in the medical field for applications against pathogens that are responsible for infections in the gastrointestinal and urogenital tracts and the skin.
乳杆菌属产生生物表面活性剂，有助于预防与泌尿生殖道和皮肤相关的微生物感染。在这里，我们描述了詹森乳杆菌 P 和加氏乳杆菌 P 产生的生物表面活性剂的生物学和物理化学性质。
L. jensenii P 和 L. gasseri P 产生的生物表面活性剂在浓度增加至临界胶束浓度（CMC）值分别为 7.1 和 8.58 mg mL 时，将水的表面张力从 72 降低至 43.2 和 42.5 mN m。对于 P 和 P 菌株，最大乳化活性分别在 1 和 5 mg mL 的浓度下获得。傅里叶变换红外光谱数据表明，生物分子由碳水化合物、脂质和蛋白质的混合物组成。詹森乳杆菌 P 生物表面活性剂的气相色谱-质谱分析显示 14-甲基十五烷酸的主要峰，这是生物分子中存在的主要脂肪酸；相反，二十烷酸在加氏乳杆菌 P 产生的生物表面活性剂中占主导地位。尽管两种生物表面活性剂都含有不同百分比的糖半乳糖、葡萄糖和核糖；但鼠李糖仅在詹森乳杆菌 P 产生的生物分子中被检测到。乳化活性在 100°C 孵育 60 分钟后、在 pH 值为 2-10 以及添加氯化钾和碳酸氢钠后保持稳定，但在存在氯化钠时则不然。生物分子对临床分离的大肠杆菌和白色念珠菌具有抗菌活性，MIC 值为 16 μg mL，对腐生葡萄球菌、产气肠杆菌和肺炎克雷伯菌的 MIC 值为 128 μg mL。生物表面活性剂还以不同浓度破坏微生物的预形成生物膜，对产气肠杆菌（64%）（P 生物表面活性剂）和大肠杆菌（46.4%）和腐生葡萄球菌（39%）（P 生物表面活性剂）更有效。两种乳杆菌菌株都可以共同聚集病原体。
本报告首次描述了詹森乳杆菌 P 和加氏乳杆菌 P 产生的生物表面活性剂的特性。这些生物分子的抗菌特性和稳定性表明，它们有潜力作为医学领域中替代抗菌剂的应用，用于治疗导致胃肠道和泌尿生殖道及皮肤感染的病原体。
