Russo-Martínez N, Vecino X, Moldes A B, Cruz J M
Chemical Engineering Department, School of Industrial Engineering - CINTECX, University of Vigo, Campus As Lagoas-Marcosende, 36310, Vigo, Spain.
Heliyon. 2024 Sep 23;10(19):e38325. doi: 10.1016/j.heliyon.2024.e38325. eCollection 2024 Oct 15.
Biosurfactants are molecules with hydrophilic and hydrophobic moieties with the capacity to reduce the surface tension of water. Given the limited quantity of biosurfactant extracts in laboratories, it is recommended to use equipment that requires minimal sample quantities for detecting the presence of biosurfactants. In this work, commercial glycolipids biosurfactants (rhamnolipids or sophorolipids) were diluted in water and subjected to different analyses to obtain their minimum surface tension (ST) reduction and their critical micellar concentration (CMC). The independent variables of the study were: the geometry of platinum plate (rectangular or cylindrical), the sample volume (2, 4 and 20 mL) and the container material consisting of either glass or polytetrafluoroethylene (PTFE). The variation of ST with biosurfactant concentration was studied based on the isotherm model proposed by Li & Lu. It was observed that the profile of ST values did not vary so much using the different independent variables described, observing that platinum rectangular plate can be used for volumes of 4 mL biosurfactants instead of cylindrical plate usually recommended for volumes lower than 20 mL, the container material was also not significant based on the Pearson and Spearman statistical treatment. Moreover, well-fitting regression model results were obtained for a non-commercial biosurfactant extract obtained from a residual stream of the dairy industry, predicting values close to the observed data.
生物表面活性剂是一种具有亲水和疏水部分的分子，能够降低水的表面张力。鉴于实验室中生物表面活性剂提取物的数量有限，建议使用所需样品量最少的设备来检测生物表面活性剂的存在。在这项工作中，将商业糖脂类生物表面活性剂（鼠李糖脂或槐糖脂）用水稀释，并进行不同分析以获得其最低表面张力（ST）降低值和临界胶束浓度（CMC）。该研究的自变量为：铂板的几何形状（矩形或圆柱形）、样品体积（2、4和20毫升）以及由玻璃或聚四氟乙烯（PTFE）组成的容器材料。基于Li和Lu提出的等温线模型研究了ST随生物表面活性剂浓度的变化。观察到，使用所述不同自变量时，ST值的分布变化不大，发现对于4毫升生物表面活性剂的体积可使用矩形铂板，而不是通常推荐用于低于20毫升体积的圆柱形板，基于Pearson和Spearman统计处理，容器材料也无显著影响。此外，对于从乳制品行业残余物流中获得的非商业生物表面活性剂提取物，获得了拟合良好的回归模型结果，预测值与观测数据接近。
