Cold-Tolerant Agriculturally Important Microorganisms

Abstract

Cold-tolerant microorganisms are endowed with the ability to grow at 0°C, though their growth optima lie in the mesophilic range. To overcome the stress induced by low temperatures they have evolved a variety of adaptive responses at the cellular and molecular levels. Multiple cell membrane modifications ensure that solute transport is not impaired at low temperatures. Other mechanisms include the synthesis of cold-shock proteins (Csps), cold acclimation proteins (Caps), cryoprotectants, ice nucleation factors, cold-adapted enzymes, and RNA degradosomes. The agricultural importance of such microbes stems from the fact that the world over temperate agro-ecosystems are characterized by low temperatures and short growing seasons that subject both plant and microbial life to cold temperature induced stress. Hence, there is a need to identify potential microbes that retain their functional traits under low temperature conditions. Such microbes can be profitably used as inoculants in agricultural production systems in the temperate regions of the world. This chapter deals with the cold tolerance/resistance mechanisms operating in microorganisms and the utility of cold-tolerant microbes in improving soil quality and productivity of agricultural crops.