工程微藻的生物安全风险、管控及生物封存

Biosafety risks, control, and biocontainment of engineered microalgae

摘要:

微藻具备利用太阳能固定CO2并转化为有机物的能力，已成为有前途的绿色细胞工厂。随着生物技术快速发展，前沿生物技术在光合微藻中的研究与应用不断拓展，对微藻的工程改造日益全面和深入，比如通过合成生物学和基因组编辑技术对微藻进行工程改造，使其有潜力应用于医学、农业、食品、能源、环境等领域。然而，与此同时，工程微藻在环境中存活和扩散的风险也随之增加，给生态环境和人类健康带来潜在安全风险。为避免其在环境中扩散对生态环境和人体健康造成生物安全风险，需要强化工程微藻生物安全风险管控政策，并针对其开发生物风险防控技术。为了实现这一目标，研究人员开发了生物封存系统(biocontainment)，包括利用有毒蛋白设计杀伤开关等主动策略和敲除必需基因制造营养缺陷型菌株等被动策略，对工程微藻进行空间上的封存。本文对近几年前沿生物技术在微藻生物工程领域的应用、工程微藻逃逸的生物安全风险和管理规范以及工程微藻中建立的多种新型生物封存技术的研究进展进行了总结和评述，最后对微藻生物封存领域的未来发展方向进行了展望。

Abstract:

Microalgae, with the ability to harness solar energy to fix CO₂ and convert it into organic compounds, have emerged as promising green cell factories. With the rapid development of cutting-edge biotechnologies, the research and application of photosynthetic microalgae have been expanding, leading to comprehensive and in-depth engineering of microalgae. The synthetic biology and genome editing technologies have enabled the applications of microalgae in medicine, agriculture, food, energy, and the environment. However, the survival and spreading of engineered microalgae in the natural environment pose potential safety risks to ecosystems and human health. To curb the risks caused by the spreading of engineered microalgae in the environment, biosafety policies should be formulated for engineered microalgae and the prevention and control technologies should be developed. Toward this goal, researchers have developed biocontainment systems, including positive strategies such as the design of toxic protein-based kill switches and passive strategies such as knocking out essential genes to construct the strains with nutritional deficiencies, thereby spatially containing engineered microalgae. This article summarizes the application of cutting-edge biotechnologies in the engineering of microalgae, the biosafety risks and management regulations associated with the escape of engineered microalgae, and the progress in novel biocontainment technologies established for engineered microalgae. Finally, this article gives insights into the future development direction of microalgae biocontainment.