Perspectives for using glacial and periglacial microorganisms for plant growth promotion at low temperatures

Even though they are among the most extreme environments in which life can develop, glaciers are colonized by metabolically active microbes, some of which thrive-in their own particular way-under the prevailing harsh conditions. Glacial or periglacial microbes are often psychrophiles since they are able to grow optimally at low temperatures. This ability has evolved through a series of adaptations, both molecular and physiological, some of which have been exploited by the biotechnological industry to develop useful products and processes. The recent discovery of cold-adapted plant growth-promoting microorganisms (PGPM) in glacial ice or periglacial soils has opened a gate to a new trove of applications due to their potential use as biofertilizers or biocontrol agents, effective in cold climates. It has been claimed that this would be of profit to increase agriculture productivity in hilly terrains, like those prevailing in the Andes or the Himalayas, since-in addition to their ability to promote plant growth through direct or indirect mechanisms-they represent an environmentally friendly alternative to the use of pesticides and chemical fertilizers. In the following chapter, I summarize the current knowledge on the identity and characteristics of such PGPM and highlight the experiences in promoting the growth of a few plant species, at low temperatures.Key Points•Countless microbes are immured in glaciers and their surroundings.•Many glacial and periglacial microbes are cold-loving (i.e., psychrophiles).•Some glacial and periglacial psychrophiles promote plant growth and development.•Plant growth-promoting psychrophiles can be used to develop biofertilizers.