Lipopeptide biosurfactants (LBs) are biological molecules with low toxicity that have aroused growing interest in the pharmaceutical industry. Their chemical structure confers antimicrobial and antibiofilm properties against different species. Despite their potential, few studies have demonstrated their capability against Malassezia spp., commensal yeasts which can cause dermatitis and serious infections. Thus, the aim of this study was to evaluate the antifungal activity of biosurfactants produced by new strains of Bacillus subtilis TIM10 and B. vallismortis TIM68 against M. furfur and their potential for removal and inhibition of yeast biofilms. Biosurfactants were classified as lipopeptides by FTIR, and their composition was characterized by ESI-Q-TOF/MS, showing ions for iturin, fengycin, and surfactin, with a greater abundance of surfactin. Through the broth microdilution method, both biosurfactants inhibited the growth of clinical M. furfur strains. Biosurfactant TIM10 showed greater capacity for growth inhibition, with no statistical difference compared to those obtained by the commercial antifungal fluconazole for M. furfur 153DR5 and 154DR8 strains. At minimal inhibitory concentrations (MIC-2), TIM10 and TIM68 were able to inhibit biofilm formation, especially TIM10, with an inhibition rate of approximately 90%. In addition, both biosurfactants were able to remove pre-formed biofilm. Both biosurfactants showed no toxicity against murine fibroblasts, even at concentrations above MIC-2. Our results show the effectiveness of LBs in controlling the growth and biofilm formation of M. furfur clinical strains and highlight the potential of these agents to compose new formulations for the treatment of these fungi.

中文翻译：

---

脂肽类生物表面活性剂对临床糠秕马拉色菌生长及生物膜形成的影响

脂肽生物表面活性剂（LBs）是一种低毒性的生物分子，在制药行业引起了越来越多的关注。它们的化学结构赋予了针对不同物种的抗菌和抗生物膜特性。尽管它们具有潜力，但很少有研究证明它们具有对抗马拉色菌属的能力，这种共生酵母菌会导致皮炎和严重感染。因此，本研究的目的是评估由枯草芽孢杆菌 TIM10 和 B. vallismortis TIM68 新菌株产生的生物表面活性剂对糠秕分枝杆菌的抗真菌活性及其去除和抑制酵母生物膜的潜力。FTIR将生物表面活性剂归类为脂肽类，ESI-Q-TOF/MS对其组成进行了表征，显示了伊图林、风菌素和表面活性素的离子，其中表面活性素的含量更高。通过肉汤微量稀释法，两种生物表面活性剂均抑制临床糠秕分枝杆菌菌株的生长。生物表面活性剂 TIM10 显示出更强的生长抑制能力，与商业抗真菌氟康唑对糠秕分枝杆菌 153DR5 和 154DR8 菌株获得的相比，没有统计学差异。在最小抑制浓度 (MIC-2) 下，TIM10 和 TIM68 能够抑制生物膜形成，尤其是 TIM10，抑制率约为 90%。此外，两种生物表面活性剂都能够去除预先形成的生物膜。两种生物表面活性剂对鼠成纤维细胞均无毒性，即使浓度高于 MIC-2。我们的研究结果表明，LBs 在控制 M 的生长和生物膜形成方面的有效性。