Center of Innovative and Applied Bioprocessing (DBT-CIAB), SAS Nagar, Mohali, India.
Department of Biotechnology, Panjab University, Chandigarh, India.
BMC Microbiol. 2020 Aug 10;20(1):246. doi: 10.1186/s12866-020-01923-3.
Himalaya is an ecologically pristine environment. The geo-tectonic activities have shaped various environmental niches with diverse microbial populations throughout the Himalayan biosphere region. Albeit, limited information is available in terms of molecular insights into the microbiome, including the uncultured microbes, of the Himalayan habitat. Hence, a vast majority of genomic resources are still under-explored from this region. Metagenome analysis has simplified the extensive in-depth exploration of diverse habitats. In the present study, the culture-independent whole metagenome sequencing methodology was employed for microbial diversity exploration and identification of genes involved in various metabolic pathways in two geothermal springs located at different altitudes in the Sikkim Himalaya.
The two hot springs, Polok and Reshi, have distinct abiotic conditions. The average temperature of Polok and Reshi was recorded to be 62 °C and 43 °C, respectively. Both the aquatic habitats have alkaline geochemistry with pH in the range of 7-8. Community profile analysis revealed genomic evidence of plentiful bacteria, with a minute fraction of the archaeal population in hot water reservoirs of Polok and Reshi hot spring. Mesophilic microbes belonging to Proteobacteria and Firmicutes phyla were predominant at both the sites. Polok exhibited an extravagant representation of Chloroflexi, Deinococcus-Thermus, Aquificae, and Thermotogae. Metabolic potential analysis depicted orthologous genes associated with sulfur, nitrogen, and methane metabolism, contributed by the microflora in the hydrothermal system. The genomic information of many novel carbohydrate-transforming enzymes was deciphered in the metagenomic description. Further, the genomic capacity of antimicrobial biomolecules and antibiotic resistance were discerned.
The study provided comprehensive molecular information about the microbial treasury as well as the metabolic features of the two geothermal sites. The thermal aquatic niches were found a potential bioresource of biocatalyst systems for biomass-processing. Overall, this study provides the whole metagenome based insights into the taxonomic and functional profiles of Polok and Reshi hot springs of the Sikkim Himalaya. The study generated a wealth of genomic data that can be explored for the discovery and characterization of novel genes encoding proteins of industrial importance.
喜马拉雅山是一个生态原始的环境。地质构造活动在整个喜马拉雅生物区系中形成了各种具有不同微生物种群的环境小生境。尽管如此，关于包括未培养微生物在内的喜马拉雅栖息地微生物组的分子见解，信息有限。因此，该地区的绝大多数基因组资源仍未得到充分探索。宏基因组分析简化了对各种生境的广泛深入探索。在本研究中，采用了独立于培养的全宏基因组测序方法，以探索位于锡金喜马拉雅山不同海拔高度的两个温泉中的微生物多样性，并鉴定与各种代谢途径相关的基因。
两个温泉，波洛克和雷希，具有不同的非生物条件。波洛克和雷希的平均温度分别记录为 62°C 和 43°C。两个水生栖息地的地球化学均呈碱性，pH 值在 7-8 之间。群落谱分析显示了大量细菌的基因组证据，而波洛克和雷希温泉热水储层中的古菌种群则很少。在两个地点，属于变形菌门和厚壁菌门的嗜中温菌均占优势。波洛克表现出 Chloroflexi、Deinococcus-Thermus、Aquificae 和 Thermotogae 的丰富代表。代谢潜力分析描绘了与硫、氮和甲烷代谢相关的微生物群在热液系统中的同源基因。在宏基因组描述中，还破译了许多新型碳水化合物转化酶的基因信息。此外，还发现了抗菌生物分子和抗生素耐药性的基因组能力。
该研究提供了有关微生物宝库以及两个地热场代谢特征的综合分子信息。热水生境被发现是生物质加工生物催化剂系统的潜在生物资源。总的来说，本研究提供了基于全宏基因组的对锡金喜马拉雅山波洛克和雷希温泉的分类和功能特征的深入了解。该研究产生了丰富的基因组数据，可以用于发现和表征具有工业重要性的新型基因编码蛋白。
