Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
Sci Total Environ. 2023 Jun 15;877:162945. doi: 10.1016/j.scitotenv.2023.162945. Epub 2023 Mar 20.
To achieve efficient and low-cost microalgae harvesting, investigations were conducted on the harvesting efficiency and potential mechanisms of Chlorella sp. HQ by filamentous fungi using two strategies, fungal spore-assisted harvesting (FSH) and fungal pellet-assisted harvesting (FPH). Five of the 19 fungal species isolated from domestic sewage could form pellets, and Aspergillus niger HW8-1 comprised the highest harvesting efficiencies of 99.17 % and 88.70 % for FPH and FSH, respectively. FSH had 2-3 times more lipids and polysaccharides in fungus-alga pellets and caused richer saturated and monounsaturated fatty acids compared with FPH. Moreover, by optimizing the microalgae preculture time, glucose concentration, and microalgae initial density, the contents of high-value substances, such as lipids, polysaccharides, and proteins of fungus-alga pellets after FPH were improved from 5.96 %, 5.67 %, and 7.27 % to 20.18 %, 24.34 % and 10.48 %, respectively. Furthermore, fungal pellets secreted more extracellular polymeric substances (EPS) during FPH than those by FSH, which could chemisorb algal cells by lowering the surface potential of fungal pellets. FPH caused algal cells to cover the outside, which increased the light exposure area of algae, thereby increasing the photosynthesis rate, whereas FSH mainly captured microalgae physically through mycelium entanglement.
为了实现高效、低成本的微藻收获，本研究采用两种策略，丝状真菌孢子辅助收获（FSH）和丝状真菌球辅助收获（FPH），对小球藻 HQ 的收获效率和潜在机制进行了研究。从国内污水中分离得到的 19 种真菌中有 5 种可以形成菌球，黑曲霉 HW8-1 的收获效率最高，分别达到 99.17%和 88.70%。FSH 形成的真菌-藻类菌球中脂质和多糖含量分别是 FPH 的 2-3 倍，且含有更丰富的饱和和单不饱和脂肪酸。此外，通过优化微藻预培养时间、葡萄糖浓度和微藻初始密度，FPH 后真菌-藻类菌球中的高价值物质（如脂质、多糖和蛋白质）的含量从 5.96%、5.67%和 7.27%分别提高到 20.18%、24.34%和 10.48%。此外，FPH 过程中真菌球比 FSH 分泌更多的胞外聚合物（EPS），通过降低真菌球的表面电位，可化学吸附藻类细胞。FPH 使藻细胞覆盖在真菌球外部，增加了藻类的受光面积，从而提高了光合作用率，而 FSH 主要通过菌丝缠结物理捕获微藻。
