Russell N J
Department of Biological Sciences, Wye College University of London, England.
Adv Biochem Eng Biotechnol. 1998;61:1-21. doi: 10.1007/BFb0102287.
Bacteria which live in cold conditions are known as psychrophiles. Since so much of our planet is generally cold, i.e. below 5 degrees C, it is not surprising that they are very common amongst a wide variety of habitats. To enable them to survive and grow in cold environments, psychrophilic bacteria have evolved a complex range of adaptations to all of their cellular components, including their membranes, energy-generating systems, protein synthesis machinery, biodegradative enzymes and the components responsible for nutrient uptake. Whilst such a systems approach to the topic has its advantages, all of the changes can be described in terms of adaptive alterations in the proteins and lipids of the bacterial cell. The present review adopts the latter approach and, following a brief consideration of the definition of psychrophiles and description of their habitats, focuses on those adaptive changes in proteins and lipids, especially those which are either currently being explored for their biotechnological potential or might be so in the future. Such applications for proteins range from the use of cold-active enzymes in the detergent and food industries, in specific biotransformations and environmental bioremediations, to specialised uses in contact lens cleaning fluids and reducing the lactose content of milk; ice-nucleating proteins have potential uses in the manufacture of ice cream or artificial snow; for lipids, the uses include dietary supplements in the form of polyunsaturated fatty acids from some Antarctic marine psychrophiles.
生活在寒冷条件下的细菌被称为嗜冷菌。由于我们这个星球的大部分地区通常都很冷，即低于5摄氏度，所以它们在各种各样的栖息地中非常常见也就不足为奇了。为了使它们能够在寒冷环境中生存和生长，嗜冷菌已经对其所有细胞成分，包括细胞膜、能量产生系统、蛋白质合成机制、生物降解酶以及负责营养吸收的成分，进化出了一系列复杂的适应性变化。虽然这种对该主题的系统方法有其优点，但所有这些变化都可以用细菌细胞中蛋白质和脂质的适应性改变来描述。本综述采用后一种方法，在简要考虑嗜冷菌的定义及其栖息地描述之后，重点关注蛋白质和脂质的那些适应性变化，特别是那些目前正在探索其生物技术潜力或未来可能会探索其生物技术潜力的变化。蛋白质的此类应用范围广泛，从在洗涤剂和食品工业中使用冷活性酶、进行特定的生物转化和环境生物修复，到在隐形眼镜清洁液中的特殊用途以及降低牛奶中的乳糖含量；冰核蛋白在冰淇淋或人造雪的制造中有潜在用途；对于脂质，其用途包括来自一些南极海洋嗜冷菌的多不饱和脂肪酸形式的膳食补充剂。
