Cold Adapted Fungi from Indian Himalaya: Untapped Source for Bioprospecting

Cold adapted microorganisms are gaining importance in view of their ability to colonize extreme low temperature environments. These microorganisms are emerging as promising source of bioactive metabolites. The Himalaya represent one of the 34 globally recognized biodiversity hotspots due to their unique and rich biodiversity. Documentation of microbial diversity from the Indian Himalayan Region (IHR) has received attention in the last two decades. The culturable microbial diversity studied in soils from high altitudes in IHR exhibited predominance of cold adapted ascomycetes fungi. Morphological and molecular characterization placed maximum number of these fungal species in the genera Penicillium, Aspergillus, Paecilomyces, Trichoderma, Cladosporium and Phialophora. Polyextremophily (tolerance to a wide range of temperature, pH and salt concentration) was one of the remarkable characteristics of these fungi. Furthermore, elevated sporulation, overproduction of enzymes and bioactive metabolites (pigments, in particular), with respect to temperature stress were observed as other characteristics of these fungi. These characteristics were attributed to the adaptation strategies of these organisms in extreme low temperature environments, along with the ‘‘resilience dependent biotechnological applications’’. Case studies exhibited the importance of ‘‘suboptimal growth conditions’’ in overproduction of metabolites that mediate ecological processes such as lignin degradation, phosphate solubilization and biocontrol.