Department of Biochemistry, University of Agriculture, Faisalabad, Pakistan.
Department of Biochemistry, University of Agriculture, Faisalabad, Pakistan.
Int J Biol Macromol. 2020 May 15;151:984-992. doi: 10.1016/j.ijbiomac.2019.11.094. Epub 2019 Nov 13.
Exopolysaccharides (EPS) are microbially-originated, complex biosynthetic polymers, mainly carbohydrates in nature. They have gained attention of modern researches due to their novel physicochemical characteristics. However, the development of cost-effective strategies to improve the EPS yield, remains a challenge. In this study, cost-effective EPS production was carried out from B. licheniformis in solid state fermentation of mango peels substrate with waste-to-value theme. Initially, B. licheniformis was exposed to ultraviolet (UV) radiations of short wavelength which significantly improved the EPS yield (from 3.4 to 4.6 g/L). The highest EPS producing mutant strain (B. licheniformis MS3) was further proceeded for yield optimization using RSM-CCD approach. Optimization improved the yield >3.2-folds (from 4.6 to 15.6 g/L). The optimally yielded fraction was characterized using HPLC, FT-IR and SEM analyses. HPLC revealed the hetero-polymeric nature of EPS containing mannose (20.60%), glucose (46.80%), and fructose (32.58%) subunits. FT-IR spectroscopy revealed the presence of hydroxyl and carboxyl functional groups, and glycosidic linkages among monosaccharides. SEM microstructure showed that EPS comprise smoother surface with less porosity. Studies on functional characteristics revealed the presence of hydrophilic moieties among EPS with moderate water (105.3%) and oil (86.3%) uptake capacity. The EPS exhibited excellent emulsifying properties showed good stability against all hydrocarbons/oils tested. In conclusion, the cost-effective EPS production with multifunctional properties, this study may be valuable for various biochemical and biotechnological sectors.
胞外多糖（EPS）是微生物来源的、复杂的生物合成聚合物，主要为天然碳水化合物。由于其新颖的物理化学特性，它们引起了现代研究的关注。然而，开发经济高效的策略来提高 EPS 产量仍然是一个挑战。在这项研究中，以芒果皮为固体发酵基质，以废物利用为主题，从地衣芽孢杆菌中进行了经济高效的 EPS 生产。最初，地衣芽孢杆菌暴露于短波长的紫外线（UV）辐射下，这显著提高了 EPS 的产量（从 3.4 增加到 4.6 g/L）。进一步使用 RSM-CCD 方法对最高 EPS 产生突变株（B. licheniformis MS3）进行产量优化。优化使产量提高了>3.2 倍（从 4.6 增加到 15.6 g/L）。使用 HPLC、FT-IR 和 SEM 分析对最优产量部分进行了表征。HPLC 显示 EPS 为杂多糖，含有甘露糖（20.60%）、葡萄糖（46.80%）和果糖（32.58%）亚基。傅里叶变换红外光谱（FT-IR）显示存在羟基和羧基官能团以及单糖之间的糖苷键。SEM 微观结构显示 EPS 由更光滑的表面和更少的孔隙组成。功能特性研究表明 EPS 中存在亲水部分，具有适度的水（105.3%）和油（86.3%）吸收能力。EPS 表现出良好的乳化性能，对所有测试的碳氢化合物/油均表现出良好的稳定性。总之，这项具有多功能特性的经济高效 EPS 生产研究可能对各种生化和生物技术领域具有重要价值。
