Systems and Synthetic Biology Program, Centro Nacional de Biotecnología CSIC Cantoblanco, Madrid, Spain.
Bioessays. 2011 Jan;33(1):38-42. doi: 10.1002/bies.201000101.
Whether occurrence of life at the physicochemical extremes results from the entire adaptation of organisms to such settings or it originates from the action of a few genes has been debated for a long time. Recent evidence suggests that a limited number of functions suffice to change the predilection of microorganisms for radically different environmental scenarios. For instance, expression of a few genes from cold-loving bacteria in mesophilic hosts allows them to grow at much lower temperatures and become heat-sensitive. This has been exploited not only for constructing Escherichia coli strains able to grow at 5-10 °C (and thus optimised as hosts for heterologous gene expression) but also for designing vaccines based on temperature-sensitive pathogens. Occurrence of genes/functions that reframe the windows of viability may also ask for a revision of some concepts in microbial ecology and may provide new tools for engineering bacteria with a superior biotechnological performance.
生命在理化极端条件下的出现是生物体对这些环境的全面适应造成的，还是由少数基因的作用造成的，这一问题长期以来一直存在争议。最近的证据表明，少数功能就足以改变微生物对截然不同的环境场景的偏好。例如，在嗜温宿主中表达来自嗜冷菌的少数基因，可以使它们在更低的温度下生长，并变得对热敏感。这不仅被用来构建能够在 5-10°C 下生长的大肠杆菌菌株（因此作为异源基因表达的宿主而得到优化），也被用来设计基于温度敏感病原体的疫苗。重新定义生存窗口的基因/功能的出现也可能需要对微生物生态学中的一些概念进行修订，并为用具有卓越生物技术性能的细菌进行工程改造提供新的工具。
