Production of extracellular polysaccharides and phycobiliproteins from Tolypothrix sp. PCC7601 using mechanical milking systems
Production of extracellular polysaccharides and phycobiliproteins from Tolypothrix sp. PCC7601 using mechanical milking systems
复制标题
DOI：
10.1016/j.algal.2020.101929
复制
发表时间：
2020-06
期刊：
影响因子：
--
通讯作者：
Alice Uchida;Yukiko Higashi;Shota Yamamoto;J. Nakanishi;N. Kanayama;K. Shibata;M. Ihara
中科院分区：
文献类型：
--
作者：
Alice Uchida;Yukiko Higashi;Shota Yamamoto;J. Nakanishi;N. Kanayama;K. Shibata;M. Ihara
近年来，微藻的生物工业应用受到广泛关注。该领域面临的挑战之一是降低种植和收获成本并实现稳定的生产力。为了解决这个问题，人们提出了新的系统，在不杀死藻类细胞的情况下提取产品。这些非破坏性提取系统称为“挤奶”。迄今为止报道的一些挤奶系统是连续过程，其中培养和挤奶同时发生，而另一些则是周期性过程，其中细胞循环培养和挤奶。这些系统基于非极性产品的有机溶剂萃取，例如脂质、萜烯和类胡萝卜素。然而，处理有机溶剂所需的特殊设施增加了成本，并且挤奶期间损失的溶剂需要回收。在这项研究中，我们研究了一种基于使用剪切分散器（玻璃均化器）的机械挤奶的无溶剂方法。我们培养了固定 N2 的丝状蓝细菌 Tolypothrixsp。 PCC7601 在非无菌农业用水中进行，并进行长期（87 天）挤奶周期以收获细胞外碳水化合物和藻胆蛋白。因此，细胞外碳水化合物的生产力和细胞密度在整个挤奶周期中保持恒定，每 3 周产生 90–140 mg/L 的细胞外碳水化合物。我们的结果表明，机械挤奶是一种实用且有效的方法，可用于稳定地从藻类中收获产品。
The bio-industrial application of microalgae has gained much attention in recent years. One of the challenges in this field is to lower the cultivation and harvest costs and to achieve the steady productivity. To address this, new systems have been proposed, in which the products are extracted without killing the algal cells. These non-destructive extraction systems are called “milking.” Some of the milking systems reported so far are continuous processes where culturing and milking occur simultaneously, and the others are a periodic process where cells are cyclically cultured and milked. These systems are based on the organic solvent extraction of non-polar products, such as lipids, terpenes, and carotenoids. However, a special facility required for handling organic solvents increases the costs and solvents lost during milking need to be recouped. In this study, we examined a solvent-free method, based on mechanical milking using a shearing disperser (glass homogenizer). We cultured the N2-fixing filamentous cyanobacteria,Tolypothrixsp. PCC7601 in non-sterile agricultural water and performed long-term (87 days) milking cycles to harvest the extracellular carbohydrates and phycobiliproteins. As a result, the productivity of extracellular carbohydrates and the cell densities remained constant throughout the milking cycle, yielding 90–140 mg/L of extracellular carbohydrates every 3 weeks. Our results demonstrated that mechanical milking is a practical and effective method that can be used to harvest products from algae steadily.