Culture Independent Diversity of Bacterial Communities Indigenous to Lower Altitude at Laohugou Glacial Environment

Abstract

High-throughput sequencing approach of the 16S rRNA gene was employed to evaluate the bacterial diversity inhabit in melted water, snow, soil, and rocks samples at the lower altitudes of the Laohugou glacial environment. Bioinformatics tools were used to process millions of Illumina reads for alpha and beta diversities of bacterial communities. The diversity indices such as Chao, Shannon, and Simpson were different in the collected samples and solid samples (soil and rocks) showed higher taxon richness and evenness. Taxonomic diversity was unexpectedly higher and the major portion of sequences was assigned to Proteobacteria, Actinobacteria, and Acidobacteria. Higher variation in community structure was reported at the class level and Alphaproteobacteria was dominant. The solid niches were occupied by a higher number of phyla compared with liquid. The physicochemical variables acted as spatial gradients and associated with the bacterial structural communities of the glacial ecosystem. Findings showed that both Proteobacteria and Actinobacteria in solid samples influenced the bacterial community structure in downstream liquid samples. Interestingly, the metagenomic biomarkers were higher in liquid samples. This study provides precious datasets to understand the bacterial community in a better way under the influence of spatial, physical and environmental factors.