生物乳化剂是一种天然或微生物基础的产品，具有乳化水中疏水化合物的能力。这些化合物可降解，环保，并且在各个行业中都有应用。从埃及亚历山大不同来源的样品中分离出13株酵母，并评估其产生胞内生物乳化剂的潜力。其中一株来自埃及当地市场的酵母，显示出最高乳化指数（EI24）的值。通过26S rRNA测序，该酵母被确定为酿酒酵母菌MYN04株。研究了该菌株的生长动力学，并在孵育36小时后获得了最高的细胞干重（CDW），为3.17 g/L，乳化指数（EI24）为55.6％。实验设计用于研究培养参数对最大化生物乳化剂SC04产量和CDW的影响。该研究实现了最大EI24为79.0±2.0％。此外，用50％乙醇沉淀和Sephadex G-75凝胶过滤色谱法纯化粗生物乳化剂。发现生物乳化剂SC04由27.1％碳水化合物和72.9％蛋白质组成。应用傅里叶变换红外光谱（FTIR）、扫描电子显微镜-能谱仪（SEM-EDX）、高效液相色谱（HPLC）和核磁共振（NMR）对纯化的生物乳化剂SC04进行了结构测定。FTIR光谱显示与碳水化合物的羧基和羟基以及蛋白质的胺基相关的特征带。HPLC分析检测到甘露糖、半乳糖和葡萄糖的存在。凝胶过滤后分级的理化学特性表明生物乳化剂SC04是一种高分子量的蛋白质-寡糖复合物。该生物乳化剂在不同pH值、温度和盐度下表现出稳定性。在0.5 mg/mL浓度下，它表现出51.8％的DPPH自由基清除能力。此外，通过MTT实验对正常上皮肾细胞系进行的体外细胞毒性评估表明，SC04对正常上皮肾细胞系没有细胞毒性。本研究介绍了一种名为SC04的新型环保生物乳化剂，具有显著的乳化能力、抗氧化和抗癌活性以及稳定性。这些发现表明SC04在食品、制药和工业领域具有广阔的应用前景。© 2023. BioMed Central Ltd., part of Springer Nature.

Bioemulsifiers are natural or microbial-based products with the ability to emulsify hydrophobic compounds in water. These compounds are biodegradable, eco-friendly, and find applications in various industries.Thirteen yeasts were isolated from different sources in Alexandria, Egypt, and evaluated for their potential to produce intracellular bioemulsifiers. One yeast, isolated from a local market in Egypt, showed the highest emulsification index (EI24) value. Through 26S rRNA sequencing, this yeast was identified as Saccharomyces cerevisiae strain MYN04. The growth kinetics of the isolate were studied, and after 36 h of incubation, the highest yield of cell dry weight (CDW) was obtained at 3.17 g/L, with an EI24 of 55.6%. Experimental designs were used to investigate the effects of culture parameters on maximizing bioemulsifier SC04 production and CDW. The study achieved a maximum EI24 of 79.0 ± 2.0%. Furthermore, the crude bioemulsifier was precipitated with 50% ethanol and purified using Sephadex G-75 gel filtration chromatography. Bioemulsifier SC04 was found to consist of 27.1% carbohydrates and 72.9% proteins. Structural determination of purified bioemulsifier SC04 was carried out using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), high-performance liquid chromatography (HPLC), and nuclear magnetic resonance spectroscopy (NMR). FTIR spectroscopy revealed characteristic bands associated with carboxyl and hydroxyl groups of carbohydrates, as well as amine groups of proteins. HPLC analysis of monosaccharide composition detected the presence of mannose, galactose, and glucose. Physicochemical characterization of the fraction after gel filtration indicated that bioemulsifier SC04 is a high molecular weight protein-oligosaccharide complex. This bioemulsifier demonstrated stability at different pH values, temperatures, and salinities. At a concentration of 0.5 mg/mL, it exhibited 51.8% scavenging of DPPH radicals. Furthermore, in vitro cytotoxicity evaluation using the MTT assay revealed a noncytotoxic effect of SC04 against normal epithelial kidney cell lines.This study presents a new eco-friendly bioemulsifier, named SC04, which exhibits significant emulsifying ability, antioxidant and anticancer properties, and stabilizing properties. These findings suggest that SC04 is a promising candidate for applications in the food, pharmaceutical, and industrial sectors.© 2023. BioMed Central Ltd., part of Springer Nature.