Coldadapted

Cold-adapted describes organisms, metabolism, or biomolecules that function efficiently at low temperatures, often near or below freezing. In ecology, it is applied to psychrophiles, which require cold conditions for growth, and psychrotrophs, which can grow at low temperatures but have higher optimums. These taxa inhabit polar seas, high mountains, and deep oceans where temperatures remain cold most of the year.

Adaptations associated with cold adaptation include: membranes with a higher proportion of unsaturated fatty acids to preserve fluidity; enzymes with greater catalytic flexibility and lower optimal temperatures; antifreeze proteins and glycoproteins that inhibit ice crystal growth; accumulation of cryoprotectants such as glycerol, trehalose, or proline; cold-shock and cold-acclimation proteins that stabilize RNA and assist protein synthesis; and regulatory changes that optimize metabolism under low energy conditions. Together, these strategies enable sustained metabolism, growth, and survival in cold habitats, though rates are often reduced compared with organisms at moderate temperatures.

Cold adaptation is a major area of research in microbiology, ecology, and biotechnology. Industrial applications include cold-active enzymes used in detergents and biocatalysis at low temperatures, bioremediation in cold environments, and food-technological uses such as texture stabilization and cryopreservation technologies. Studying cold adaptation also informs understanding of protein folding, membrane biophysics, and evolutionary responses to thermal constraints.