Baptista Sílvia, Torres Cristiana A V, Sevrin Chantal, Grandfils Christian, Reis Maria A M, Freitas Filomena
Associate Laboratory i4HB-Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, 2819-516 Caparica, Portugal.
UCIBIO-Applied Molecular Biosciences Unit, Department of Chemistry, School of Science and Technology, NOVA University Lisbon, 2819-516 Caparica, Portugal.
Polymers (Basel). 2022 Jan 19;14(3):390. doi: 10.3390/polym14030390.
In this study, membrane-based methods were evaluated for the recovery of FucoPol, the fucose-rich exopolysaccharide (EPS) secreted by the bacterium A47, aiming at reducing the total water consumption and extraction time, while keeping a high product recovery, thus making the downstream procedure more sustainable and cost-effective. The optimized method involved ultrafiltration of the cell-free supernatant using a 30 kDa molecular weight cut-off (MWCO) membrane that allowed for a 37% reduction of the total water consumption and a 55% reduction of the extraction time, compared to the previously used method (diafiltration-ultrafiltration with a 100 kDa MWCO membrane). This change in the downstream procedure improved the product's recovery (around 10% increase) and its purity, evidenced by the lower protein (8.2 wt%) and inorganic salts (4.0 wt%) contents of the samples (compared to 9.3 and 8.6 wt%, respectively, for the previously used method), without impacting FucoPol's sugar and acyl groups composition, molecular mass distribution or thermal degradation profile. The biopolymer's emulsion-forming and stabilizing capacity was also not affected (emulsification activity (EA) with olive oil, at a 2:3 ratio, of 98 ± 0% for all samples), while the rheological properties were improved (the zero-shear viscosity increased from 8.89 ± 0.62 Pa·s to 17.40 ± 0.04 Pa·s), which can be assigned to the higher purity degree of the extracted samples. These findings demonstrate a significant improvement in the downstream procedure raising FucoPol's recovery, while reducing water consumption and operation time, key criteria in terms of process economic and environmental sustainability. Moreover, those changes improved the biopolymer's rheological properties, known to significantly impact FucoPol's utilization in cosmetic, pharmaceutical or food products.
在本研究中，对基于膜的方法进行了评估，以回收由细菌A47分泌的富含岩藻糖的胞外多糖（EPS）——岩藻聚糖，旨在减少总用水量和提取时间，同时保持高产品回收率，从而使下游工艺更具可持续性和成本效益。优化后的方法包括使用截留分子量为30 kDa的膜对无细胞上清液进行超滤，与之前使用的方法（使用截留分子量为100 kDa的膜进行渗滤-超滤）相比，总用水量减少了37%，提取时间减少了55%。下游工艺的这种变化提高了产品回收率（提高了约10%）及其纯度，样品中较低的蛋白质（8.2 wt%）和无机盐（4.0 wt%）含量证明了这一点（相比之下，之前使用的方法分别为9.3 wt%和8.6 wt%），且不影响岩藻聚糖的糖基和酰基组成、分子量分布或热降解特性。生物聚合物的乳化形成和稳定能力也未受影响（所有样品与橄榄油以2:3比例混合时的乳化活性（EA）均为98±0%），而流变学性质得到改善（零剪切粘度从8.89±0.62 Pa·s增加到17.40±0.04 Pa·s），这可归因于提取样品的纯度更高。这些发现表明下游工艺有显著改进，提高了岩藻聚糖的回收率，同时减少了用水量和操作时间，这是工艺经济和环境可持续性方面的关键标准。此外，这些变化改善了生物聚合物的流变学性质，已知这会对岩藻聚糖在化妆品、药品或食品中的应用产生重大影响。
