Kim Inhyup, Chhetri Geeta, So Yoonseop, Kim Jiyoun, Seo Taegun
Department of Life Science, Dongguk University-Seoul, Goyang 10326, Korea.
Microorganisms. 2022 Jun 21;10(7):1257. doi: 10.3390/microorganisms10071257.
In the present study, exopolysaccharide (EPS) produced by sp. MMG2 (lyEPS) was characterized and purified. The lyEPS-producing strain sp. MMG2 was isolated from the roots of . When lyEPS was produced in tryptic soy broth with 1% glucose and the lyophilized powder was measured, the yield was found to be 0.67 g/L. The molecular weight (Mw) of lyEPS was 1.01 × 105 Da. Its monosaccharide composition includes 84.24% mannose, 9.73% glucose, 2.55% galactose, 2.77% arabinose, 0.32% xylose, and 0.03% rhamnose. Scanning electron microscopy (SEM) revealed that lyEPS has various round and rough surfaces. Fourier-transform infrared (FTIR) analysis identified its carbohydrate polymer functional groups. Moreover, thermogravimetric analysis of lyEPS revealed two events of mass loss: the first was water loss, which resulted in 3.97% mass loss and the second event occurred at approximately 212 °C. lyEPS could inhibit biofilm-producing pathogenic bacteria without any antimicrobial activity. Furthermore, lyEPS at a concentration of 4 mg/mL could exhibit potent 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging activity (89.25%). These results indicate that lyEPS could be a promising candidate for industrial development if its biological activity is further explored.
在本研究中，对菌株MMG2产生的胞外多糖（EPS，lyEPS）进行了表征和纯化。产生lyEPS的菌株MMG2是从[植物名称]的根部分离得到的。当在含有1%葡萄糖的胰蛋白胨大豆肉汤中生产lyEPS并对冻干粉末进行测定时，发现产量为0.67 g/L。lyEPS的分子量（Mw）为1.01×10⁵ Da。其单糖组成包括84.24%的甘露糖、9.73%的葡萄糖、2.55%的半乳糖、2.77%的阿拉伯糖、0.32%的木糖和0.03%的鼠李糖。扫描电子显微镜（SEM）显示lyEPS具有各种圆形且粗糙的表面。傅里叶变换红外（FTIR）分析确定了其碳水化合物聚合物官能团。此外，lyEPS的热重分析显示有两个质量损失事件：第一个是水分损失，导致质量损失3.97%，第二个事件发生在约212℃。lyEPS可以抑制产生生物膜的病原菌，且没有任何抗菌活性。此外，浓度为4 mg/mL的lyEPS可表现出较强的2,2-二苯基-1-苦基肼（DPPH）自由基清除活性（89.25%）。这些结果表明，如果进一步探索其生物活性，lyEPS可能是工业开发的一个有前景的候选物。
