Abstract
The current examination incorporates the evaluation of limnological boundaries influencing the microbial diversity and its distribution in the Hemkund Lake, a high altitude aquatic body located at an elevation of 4,170 m a.s.l. in the Himalayan state Uttarakhand of India. Samples of water were collected for three continuous years (2018-2020) in three sampling attempts each year. Four water sampling sites were identified and studied across the lake during two years of the study periods. A total of nineteen physicochemical parameters of lake water were recorded. Few of the parameters were analyzed at the site whereas the leftover parameters were analyzed in the laboratory at the Department. The diversity of microorganisms was determined via morphological, biochemical, MALDI-TOF MS, and molecular approaches (16S and 18S rRNA sequencing). Environmental variables i.e., DO, BOD, total coliform, and TDS showed huge variation at site 2 among all the four water sampling sites. The water temperature of Hemkund Lake was observed from 4.9°C to 6.1°C whereas; dissolved oxygen was recorded from 6.0 to 8.2 mg.l-1. The α-diversity of microorganisms in the Hemkund Lake was found to be nineteen with ten bacterial strains, four actinomycetes strains, and five fungal strains. Janthinobacterium lividum, Pseudomonas tolaasii, Pseudomonas rhodesiae, and Pseudomonas fluorescens are a few important and key species that were found in the lake water. The present study on the diversity of psychrophilic microorganisms in the high altitude Lake Hemkund could be a great reference for further research activities on comparable viewpoints in different parts of the Himalaya. This baseline information can also help the administrative officials to take necessary steps for its conservation and management.