The Wild Ass Sanctuary, Little Rann of Kutch is a typical ecological system with saline desert climate with least floral diversity and unique faunal diversity. The area has been declared as a wildlife sanctuary for protection of free ranging population of the Indian Wild Ass (Equus hemionus khur). The present paper explores this unique ecosystem in the light of its microbial diversity. Microorganisms were isolated from the soil samples collected from different areas of the sanctuary by enrichment isolation technique using the variables of pH and salinity. Primary characterization of soil samples was done with reference to Water Holding Capacity (WHC), pH, organic carbon, salinity and fluoride which revealed diverse and unique soil type. The isolates were further studied for morphological and biochemical heterogenecity. Due to the hyper saline and hyper alkaline environment, the investigated microflora were having dominated population including alkalophiles, halophiles and haloalkalophiles. Extremophilic isolates were further screened for extracellular enzyme in the extreme environment which suggests a possible biotechnological implication, besides the first significance in biodiversity and their role in the ecosystem.

The Wild Ass Sanctuary, Little Rann of Kutch is a typical ecological system with saline desert climate having least floral diversity and unique faunal diversity. The Sanctuary has been specially protected for the free ranging population of the Indian wild ass (Equus hemionus khur). The area has dry tropical monsoon climate. It receives an average annual rainfall of less than 300 mm. The average maximum temperature is about 42 °C and average minimum temperature is about 12 °C. However, the maximum temperature recorded was as high as 50 °C and minimum was as low as 1 °C during the study period. The area is a seasonally-flooded wetland ecosystem. During monsoon, a gradual variation of salinity occurs and a concentration gradient of the same was observed from sea water to the river water when they empty into the fringes of the Rann.

The Rann does not have sand dunes, but has a vast tract of flat saline land, which goes under knee-deep water in the monsoon, leaving uplands or raised lands, above submergence level known as Beit (Singh, 2000). The sanctuary area is internationally unique, incomparable, and one of the most unusual areas of the world. Uniqueness of the area and the existence of rare and endangered species qualify the Little Rann as one of the first 13 wilderness areas selected for conservation and development as the biosphere reserves in the country. The area sustains a unique composition of floral species that harbor a variety of wild life, characteristic to the area, 253 species of plants, 107 species of phytoplankton, 34 species of herpetofauna, over four dozen species of mammals, and 181 species of birds have been recorded in the sanctuary, which include some of the endemic and rare species.

Study on Microbial Diversity of Wild Ass Sanctuary, Little Rann of Kutch, Equus hemionus khur, ecological system, sand dunes, Beit, endangered species, biosphere reserves, floral species, phytoplankton, herpetofauna, Water Holding Capacity (WHC), organic carbon, extracellular enzyme, biochemical heterogenecity.