Hot springs of Indian Himalayas: potential sources of microbial diversity and thermostable hydrolytic enzymes

Abstract

Microbial communities in hot springs at high elevations have been extensively studied worldwide. In this sense, the Indian Himalaya regions is valuable ecosystems for providing both the extreme 'cold' and 'hot' sites for exploring microbial diversity. In the present study, a total of 140 thermophilic bacteria were isolated from 12 samples collected from Manikaran and Yumthang hot springs of Indian Himalayas. The bacterial isolates were studied for phylogenetic profiling, growth properties at varying conditions and potential sources of extracellular thermostable hydrolytic enzymes such as protease, amylase, xylanase and cellulase. Based on production of extracellular hydrolases, 51 isolates from Manikaran (28) and Yumthang thermal springs (23) were selected and identified using 16S rRNA gene sequencing which included 37 distinct species of 14 different genera namely Anoxybacillus, Bacillus, Brevibacillus, Brevundimonas, Burkholderia, Geobacillus, Paenibacillus, Planococcus, Pseudomonas, Rhodanobacter, Thermoactinomyces, Thermobacillus, Thermonema and Thiobacillus. Out of 51 hydrolase producing bacteria, 24 isolates showed stability at wide range of temperature and pH treatments. In present investigation, three thermotolerant bacteria namely, Thermobacillus sp NBM6, Paenibacillus ehimensis NBM24 and Paenibacillus popilliae NBM68 were found to produced cellulase-free xylanase. These potential extracellular thermostable hydrolytic enzymes producing thermophilic bacteria have a great commercial prospect in various industrial, medical and agriculture applications.

Diversity and enzymatic potential of thermophilic bacteria associated with terrestrial hot springs in Algeria

“…This is likely due to endospore-forming ability of these bacteria representing a successful survival strategy and dominance under high temperature conditions [68]. Similarly, many reports indicate the abundance of the phylum Firmicutes in extreme environments [9]. A total of 23% of Firmicutes were represented by Paenibacillaceae (Aneurinibacillus and Brevibacillus), following the finding by Kumar et al [69].…”

“…Geothermal springs are considered unique hot spots for large communities of thermophilic microorganisms, mainly belonging to Bacteria and Archaea domains [9]. Thermophile biodiversity can provide an overview of the potential, and such studies are required not only to understand the microbial community's organization and composition but also led to further discovery of novel taxa and to resolve the role of microorganisms in the community [10].…”

Microbial Ecology from the Himalayan Cryosphere Perspective

“…Even in the presence of very high temperatures (>40 • C), the complexity of microbial communities is maintained. These hot springs have been reported to possess a high diversity of hyperthermophiles and thermophilic bacteria [68][69][70][71][72][73]. The microbial interactions and the flow of flux was also assessed through metagenome analysis [74,75].…”

Elucidating Mechanisms of Endophytes Used in Plant Protection and Other Bioactivities With Multifunctional Prospects

“…As the years' progress, researchers are beginning to see prospects in microbial enzyme production. There are many reports currently that microorganisms isolated from the extreme environments have great biotechnological applications in medicine, agriculture, and industry (Archna et al, 2015;Yadav et al, 2015;Singh et al, 2016;Sahay et al, 2017). This review aimed to present the various mechanisms of action used by endophytes in protecting a plant and report some bioactivities of importance to people with special emphasis on endophytic bacteria and fungi.…”