Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China.
School of Biotechnology, Jiangnan University, Wuxi 214122, China.
Int J Mol Sci. 2023 Aug 3;24(15):12389. doi: 10.3390/ijms241512389.
Cyanobacterial harmful algal blooms (CyanoHABs) pose significant threats to human health and natural ecosystems worldwide, primarily caused by water eutrophication, increased surface water temperature, and co-occurring microorganisms. Urgent action is needed to develop an eco-friendly solution to effectively curb the proliferation of CyanoHABs. Sophorolipids (SLs) are fully biodegradable biosurfactants synthesized by . They can be classified into lactone and acid types. The lactone type displays strong antimicrobial activity, while the acid type exhibits good solubility, which make them ideal agents for mitigating CyanoHABs. Nevertheless, the broad utilization of SLs are hindered by their expensive production costs and the absence of effective genetic editing tools in the native host. In this study, we constructed recombinant strains capable of producing either acidic or lactonic SLs using the CRISPR-Cas9 gene editing system. The yields of acidic and lactonic SLs reached 53.64 g/L and 45.32 g/L in a shaking flask, respectively. In a 5 L fermenter, acidic SLs reached 129.7 g/L using low-cost glucose and rapeseed oil as substrates. The addition of 5 mg/L lactonic SLs effectively degraded cyanobacteria within 30 min, and a ratio of 8.25:1.75 of lactonic to acidic SLs showed the highest degradation efficiency. This study offers a safe and promising solution for CyanoHABs treatment.
蓝藻有害藻华（CyanoHABs）对全球人类健康和自然生态系统构成重大威胁，主要由水体富营养化、地表水温度升高和共生微生物引起。需要采取紧急行动，开发环保解决方案，有效遏制 CyanoHABs 的增殖。槐糖脂（SLs）是由 合成的完全可生物降解的生物表面活性剂。它们可分为内酯型和酸型。内酯型具有较强的抗菌活性，而酸型具有良好的溶解性，是减轻 CyanoHABs 的理想药剂。然而，由于其生产成本高和天然宿主中缺乏有效的遗传编辑工具，SLs 的广泛应用受到限制。在本研究中，我们使用 CRISPR-Cas9 基因编辑系统构建了能够分别产生酸性或内酯型 SLs 的重组菌株。在摇瓶中，酸性和内酯型 SLs 的产量分别达到 53.64 g/L 和 45.32 g/L。在 5 L 发酵罐中，以低成本葡萄糖和菜籽油为底物，酸性 SLs 达到 129.7 g/L。添加 5 mg/L 内酯型 SLs 可在 30 min 内有效降解蓝藻，内酯型与酸性 SLs 的比例为 8.25:1.75 时降解效率最高。本研究为 CyanoHABs 处理提供了一种安全且有前景的解决方案。
