Gil Cátia V, Rebocho Ana Teresa, Esmail Asiyah, Sevrin Chantal, Grandfils Christian, Torres Cristiana A V, Reis Maria A M, Freitas Filomena
Laboratory i4HB-Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, 1099-085 Caparica, Portugal.
UCIBIO-Applied Molecular Biosciences Unit, Department of Chemistry, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal.
Polymers (Basel). 2022 May 20;14(10):2088. doi: 10.3390/polym14102088.
Biosurfactants synthesized by microorganisms represent safe and sustainable alternatives to the use of synthetic surfactants, due to their lower toxicity, better biodegradability and biocompatibility, and their production from low-cost feedstocks. In line with this, the present study describes the physical, chemical, and functional characterization of the biopolymer secreted by the bacterium Burkholderia thailandensis DSM 13276, envisaging its validation as a biosurfactant. The biopolymer was found to be a glycolipopeptide with carbohydrate and protein contents of 33.1 ± 6.4% and 23.0 ± 3.2%, respectively. Galactose, glucose, rhamnose, mannose, and glucuronic acid were detected in the carbohydrate moiety at a relative molar ratio of 4:3:2:2:1. It is a high-molecular-weight biopolymer (1.0 × 107 Da) with low polydispersity (1.66), and forms aqueous solutions with shear-thinning behavior, which remained after autoclaving. The biopolymer has demonstrated a good emulsion-stabilizing capacity towards different hydrophobic compounds, namely, benzene, almond oil, and sunflower oil. The emulsions prepared with the biosurfactant, as well as with its autoclaved solution, displayed high emulsification activity (>90% and ~50%, respectively). Moreover, the almond and sunflower oil emulsions stabilized with the biosurfactant were stable for up to 4 weeks, which further supports the potential of this novel biopolymer for utilization as a natural bioemulsifier.
微生物合成的生物表面活性剂是合成表面活性剂安全且可持续的替代品，因为它们毒性较低、具有更好的生物降解性和生物相容性，并且可以由低成本原料生产。与此一致的是，本研究描述了泰国伯克霍尔德菌DSM 13276分泌的生物聚合物的物理、化学和功能特性，旨在验证其作为生物表面活性剂的有效性。发现该生物聚合物是一种糖脂肽，碳水化合物和蛋白质含量分别为33.1±6.4%和23.0±3.2%。在碳水化合物部分检测到半乳糖、葡萄糖、鼠李糖、甘露糖和葡萄糖醛酸，其相对摩尔比为4:3:2:2:1。它是一种高分子量生物聚合物（1.0×107 Da），多分散性低（1.66），形成具有剪切变稀行为的水溶液，高压灭菌后仍保持这种性质。该生物聚合物对不同的疏水化合物，即苯、杏仁油和向日葵油，表现出良好的乳化稳定能力。用生物表面活性剂及其高压灭菌溶液制备的乳液显示出高乳化活性（分别>90%和~50%）。此外，用生物表面活性剂稳定的杏仁油和向日葵油乳液可稳定长达4周，这进一步支持了这种新型生物聚合物作为天然生物乳化剂的应用潜力。
