Bacterial Diversity in an Alpine Debris-Free and Debris-Cover Accumulation Zone Glacier Ice, North Sikkim, India

Abstract

The Himalayas are water tower for billions of people; however in recent years due to climate change several glaciers of Himalaya are receding or getting extinct which can lead to water scarcity and political tensions.

Thus, it requires immediate attention and necessary eval- uation of all the environmental parameters which can lead

to conservation of Himalayan glaciers. This study is the first attempt to investigate the bacterial diversity from debris-free Changme Khang (CKG) and debris-cover Changme Khangpu (CK) glacier, North Sikkim, India. The abundance of culturable bacteria in CKG glaciers was 1.5 9 104 cells/mL and CK glacier 1.5 9 105 cells/mL. A total of 50 isolates were isolated from both the glacier

under aerobic growth condition. The majority of the iso- lates from both the glaciers were psychrotolerant according

to their growth temperature. Optimum growth temperatures of the isolates were between 15 and 20 C, pH 6–8 and NaCl 0–2%. The phylogenetic studies of 16S RNA gene sequence suggest that, these 21 isolates can be assigned

within four phyla/class, i.e., Firmicutes, Beta-proteobacte- ria, Gamma-proteobacteria and Actinobacteria. The domi- nant phyla were Firmicutes 71.42% followed by

Actinobacteria 14.28%, Alpha-proteobacteria 9.52% and Beta-proteobacteria 4.76%. The isolate Bacillus thuringiensis strain CKG2 showed the highest protease activity (2.24 unit/mL/min). Considering the fast rate at which Himalayan glaciers are melting and availability of limited number of research, there is urgent need to study the microbial communities confined in such environments.