Department of Biotechnology, Faculty of Science and Technology, Thammasat University, Rangsit Centre, Pathum Thani 12120, Thailand.
Department of Biotechnology, Faculty of Science and Technology, Thammasat University, Rangsit Centre, Pathum Thani 12120, Thailand.
Int J Biol Macromol. 2020 Oct 15;161:917-926. doi: 10.1016/j.ijbiomac.2020.06.116. Epub 2020 Jun 16.
Commercial- and laboratory modified- cationic cassava starches and their composites with magnetic particles were examined for characteristics and separation efficiency. Scanning electron micrographs showed that cationic starch with an increasing degree of substitution (DS) value (0.0180 to 0.91) showed greater clumped polyhedral granules and became markedly enlarged with disintegrated boundaries. Zeta potential analysis revealed that the increase in the DS value in cationic starches resulted in an increase in positive charge. The maximum harvesting efficiency of 92.86 ± 0.46% was achieved when commercial cationic starch with DS 0.040 at 1.0 g L was added to the Chlorella sp. solution. The maximum recovery capacity (10.20 ± 0.16 g DCW g starch) was recorded by using commercial cationic starch with DS 0.040 at a lower dosage of 0.1 g L. Their composites showed lower separation efficiency than the commercial cationic starches. The results suggest that the commercial cationic cassava starch with 0.040 DS shows great potential as a flocculant for algal separation. This first report of using commercial cationic cassava starch as a flocculant provides a low cost and convenient process to separate algal cells from the culture medium. Moreover, uncontaminated magnetic particle biomass allows for wide range of algal utilization in food and pharmaceutical biotechnologies.
商用和实验室改性的阳离子木薯淀粉及其与磁性颗粒的复合材料的特性和分离效率进行了研究。扫描电子显微镜照片显示，取代度（DS）值（0.0180 至 0.91）逐渐增加的阳离子淀粉显示出更大的团块状多面体颗粒，并由于边界崩解而显著增大。Zeta 电位分析表明，阳离子淀粉中 DS 值的增加导致正电荷增加。当在 1.0 g/L 时添加 DS 为 0.040 的商用阳离子淀粉时，小球藻的最大收获效率达到 92.86 ± 0.46%。使用 DS 为 0.040 的商用阳离子淀粉在较低的 0.1 g/L 用量下，记录到最大回收容量（10.20 ± 0.16 g DCW g 淀粉）。它们的复合材料的分离效率低于商用阳离子淀粉。结果表明，DS 为 0.040 的商用阳离子木薯淀粉作为藻类分离的絮凝剂具有很大的潜力。这是首次报道使用商用阳离子木薯淀粉作为絮凝剂，为从培养基中分离藻类细胞提供了一种低成本且方便的工艺。此外，无污染的磁性颗粒生物质允许在食品和制药生物技术中广泛利用藻类。
