Diversity of Culturable Psychrophilic Fungi from Tirich Mir Glacier, Chitral

Abstract

The term psychrophile means organisms that love to grow at low temperature. More than 70% of Earth crust has temperature less 5°C, so this provides a large space as a habitat for psychrophiles. The low temperature environments include; sea water, polar region, European Alps, Rocky Mountains of Americas and the mountains of Asia, having highest peaks of the world i.e. Hindu Kush, Karakoram and Himalaya. There are more than 5000 small and large glaciers in these mountain ranges in the northern areas of Pakistan. Tirich Mir is the highest peak of Hindu Kush mountain range in Chitral, KPK. The current study explores the diversity of fungi in Tirich Mir glacier. The samples were collected in the form of subsurface ice, surface ice and sediment. Total viable count (CFU/ml) was determined by spread plate method at 4°C and 15°C. Isolates were identified by morphologically and microscopically and confirmed by 18S rRNA gene sequencing. The growth of the isolates was also characterized on the basis of their tolerance on NaCl, pH, temperature and media. The CFU/ml at 4°C was 4.2 x 102, 8.5 x 102 and 0 in surface ice, sediment and subsurface ice respectively. Similarly CFU/ml at 15°C was 5, 4.5 x 102 and 1.025 x 103 in subsurface, surface and sediment respectively. Total 25 different strains were isolated at 4°C and 32 different fungal strains were at 15°C. The growth of all the isolates was checked on different salt concentrations. The range for the salt concentrations for strains isolated at 4°C and 15°C was same i.e. 2 - 20%. The range for the temperature for the strains isolated at 4°C was i.e. 15, 37 and 55°C and for the strains isolated at 15°C was 4, 37 and 55°C. The strains showed a great variety of psychrophilic nature. Then growth of isolated strains was checked on different pH and the result showed a different variety of these isolated fungal strains. The pH range for both type of fungal isolates i.e. isolates at 4°C and 15°C was same; i.e. pH 1.0, 3.0, 5.0, 6.0, 7.0, 8.0, 9.0 and 11.0. This pH study explores their acidophilic and alkaliphilic nature. For the microscopic identification, the slides were stained with lactophenol cotton blue and examined under 40 X magnification. Phylogenetic analysis was done for further identification and characterization.