Biocontainment systems are crucial for preventing genetically modified organisms from escaping into natural ecosystems. Here, we describe the orthogonal ribosome biofirewall, which consists of an activation circuit and a degradation circuit. The activation circuit is a genetic AND gate based on activation of the encrypted pathway by the orthogonal ribosome in response to specific environmental signals. The degradation circuit is a genetic NOT gate with an output of I-SceI homing endonuclease, which conditionally degrades the orthogonal ribosome genes. We demonstrate that the activation circuit can be flexibly incorporated into genetic circuits and metabolic pathways for encryption. The plasmid-based encryption of the deoxychromoviridans pathway and the genome-based encryption of lacZ are tightly regulated and can decrease the expression to 7.3% and 7.8%, respectively. We validated the ability of the degradation circuit to decrease the expression levels of the target plasmids and the orthogonal rRNA (O-rRNA) plasmids to 0.8% in lab medium and 0.76% in nonsterile soil medium, respectively. Our orthogonal ribosome biofirewall is a versatile platform that can be useful in biosafety research and in the biotechnology industry.

中文翻译：

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正交核糖体生物防火墙

生物遏制系统对于防止转基因生物逃逸到自然生态系统中至关重要。在这里，我们描述了正交核糖体生物防火墙，它由一个激活电路和一个降解电路组成。激活电路是遗传“与”门，基于正交核糖体响应特定环境信号激活加密途径。降解电路是遗传性非门，具有I-SceI归巢核酸内切酶的输出，可有条件地降解正交核糖体基因。我们证明了激活电路可以灵活地整合到遗传电路和代谢途径进行加密。脱氧染色质抗体途径的基于质粒的加密和lacZ的基于基因组的加密受到严格调控，可将其表达降低至7。分别为3％和7.8％。我们验证了降解电路将目标质粒和正交rRNA（O-rRNA）质粒的表达水平分别在实验室培养基和非无菌土壤培养基中分别降低至0.8％和0.76％的能力。我们的正交核糖体生物防火墙是一个多功能平台，可用于生物安全研究和生物技术行业。