In order to meet the challenges of climate change, synthetic biology can target the functions of human symbiotic microorganisms or cells to enhance the adaptability of specific populations to environmental pressures (such as high temperature, drought, air pollution, or pathogens). The following is the step-by-step design plan： --- ### **1. Target selection and gene circuit design** -**Targeted adaptation phenotypes**: Select key pathways related to climate adaptation, such as： -**Heat shock protein (HSP)**: Enhances the ability of cells to withstand high temperature. -**Antioxidant enzymes (SOD, catalase)**: Resist oxidative damage caused by ultraviolet rays or air pollution. -**Water channel protein (AQP)**: Optimize water utilization efficiency and adapt to drought. -**Vitamin D synthesis pathway**: To make up for the lack of sunlight in high latitudes. -**Gene circuit**: Design inducible promoter (such as temperature-sensitive or oxidative stress-responsive) to activate target gene expression under specific environmental signals. --- ### **2. Delivery system development** -**Engineering symbiotic microorganisms**： - *Skin microorganisms* (such as Staphylococcus epidermidis): deliver sunscreen pigments (melanin) or antioxidants. - *Intestinal microorganisms* (such as E. coli Nissle 1917): synthesize essential nutrients (such as vitamin B12) or regulate electrolyte balance. -**Human cell transformation** (carefully assess ethical risks)： -CRISPR-Cas9 is used to knock out the heat shock protein gene in epidermal stem cells to enhance heat resistance for a long time. --- ### **3. Dynamic response and security** -**Environmental sensing system**: A two-component regulatory system (such as PhoPQ) is used to enable microorganisms to activate protective genes only at high temperature/low pH. -**Biological containment strategy**： -Essential gene dependence (engineering bacteria rely on exogenous amino acids to survive). -Suicide switch (apoptosis is triggered after the environmental signal disappears). --- ### **4. Ethical and social considerations** -**Controllability and reversibility**: Strictly limit the scope of application of technology (for example, only for disaster relief personnel in extreme climatic areas). -**Fairness**: Ensure that technology accessibility does not exacerbate global inequality. -**Ecological risk assessment**: Prevent the impact of the escape of engineering microorganisms on the ecological chain. --- ### **5. Experimental verification path** -**In vitro model**: Test the heat resistance/antioxidant effect in an organoid or skin equivalent model. - **Animal model**: Transgenic mice were used to verify the promotion of high temperature adaptation of engineering bacteria. -**Small-scale population trial**: Test the safety of skin microbial therapy under strict supervision. --- ###**Potential application scenarios** -**Emergency disaster relief**: Provide short-term microbial protection for outdoor workers in high-temperature heat wave areas. -**Long-term adaptation**: Help residents in drought areas improve water utilization through modified intestinal microorganisms. This approach needs to be combined with a multid disciplinary regulatory framework to ensure that the benefits of technology far outweigh the risks. In the initial stage, it is recommended to give priority to the development of non-hereditary and reversible microbial interventions.