Pehlivan Aslı Deniz, Bozdemir Melek Tijen, Ozbas Zekiye Yesim
Faculty of Engineering, Department of Food Engineering, Hacettepe University, Beytepe, 06800 Ankara, Turkey.
Faculty of Engineering, Department of Chemical Engineering, Hacettepe University, Beytepe, 06800 Ankara, Turkey.
ACS Omega. 2025 Aug 6;10(32):35578-35594. doi: 10.1021/acsomega.5c00804. eCollection 2025 Aug 19.
Liamocins are unique extracellular glycolipid biosurfactants produced by certain species of with potential applications in agriculture, food, medicine, and pharmaceutical industries due to their surface-active properties and antimicrobial activity. In this study, for the first time, optimization of various fermentation parameters for liamocin production by NBRC 100716 strain was carried out using the response surface methodology (RSM). By conducting numeric optimization, the optimum conditions were determined as follows: initial substrate (fructose) concentration (1) of 93.47 g/L, initial pH (2) of 4.92, and temperature (3) of 27.2 °C. Under optimum conditions, the maximum liamocin concentration (1), microorganism-specific growth rate (2), and maximum specific liamocin production rate (3) were found to be 3.56 g/L, 0.0670 h, and 0.00450 [g liamocin/(g mo·h)], respectively. Variations of the responses with the independent variables were defined by a quadratic model. According to the analysis of variance (ANOVA) results, the model terms in the study showed high significance ( < 0.05) for all response variables, while the lack of fit was not significant for any of the responses. The coefficient of determination for liamocin production (0.829) was close to 1.0, confirming the significance of the model. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) determined that the liamocin structure contained all liamocin types referred to as A1, B1, A2, and B2. By the gas chromatography-flame ionization detection (GC-FID) method, it was determined that 61.12% of the fatty acid composition consisted of saturated and 38.87% consisted of unsaturated fatty acids (UFA). Furthermore, Fourier transform infrared spectrometry (FT-IR) spectral attributes were used for the first time to confirm the structure of liamocin, providing valuable insights. This study, in which some fermentation parameters were optimized, showed that the NBRC 100716 strain is promising for industrial-scale liamocin production in the future.
利亚莫菌素是由某些物种产生的独特的细胞外糖脂生物表面活性剂，由于其表面活性特性和抗菌活性，在农业、食品、医药和制药行业具有潜在应用价值。在本研究中，首次使用响应面法（RSM）对NBRC 100716菌株生产利亚莫菌素的各种发酵参数进行了优化。通过数值优化，确定最佳条件如下：初始底物（果糖）浓度（1）为93.47 g/L，初始pH（2）为4.92，温度（3）为27.2℃。在最佳条件下，发现利亚莫菌素的最大浓度（1）、微生物比生长速率（2）和最大比利亚莫菌素生产率（3）分别为3.56 g/L、0.0670 h和0.00450 [g利亚莫菌素/（g mo·h）]。响应变量与自变量的变化关系由二次模型定义。根据方差分析（ANOVA）结果，研究中的模型项对所有响应变量均显示出高度显著性（<0.05），而失拟对任何响应均不显著。利亚莫菌素生产的决定系数（0.829）接近1.0，证实了模型的显著性。基质辅助激光解吸电离飞行时间质谱（MALDI-TOF-MS）确定利亚莫菌素结构包含所有被称为A1、B1、A2和B2的利亚莫菌素类型。通过气相色谱-火焰离子化检测（GC-FID）方法，确定脂肪酸组成中61.12%为饱和脂肪酸，38.87%为不饱和脂肪酸（UFA）。此外，首次使用傅里叶变换红外光谱（FT-IR）光谱属性来确认利亚莫菌素的结构，提供了有价值的见解。这项对一些发酵参数进行优化的研究表明，NBRC 100716菌株在未来工业规模生产利亚莫菌素方面具有前景。
