Analysis of the metatranscriptome of microbial communities of an alkaline hot sulfur spring revealed different gene encoding pathway enzymes associated with energy metabolism

Abstract

Alkaline sulfur hot springs notable for their specialized and complex ecosystem powered by geothermal energy are abundantly rich in different chemotrophic and phototrophic thermophilic microorganisms. Survival and adaptation of these organisms in the extreme environment is specifically related to energy metabolism. To gain a better understanding of survival mechanism of the organisms in these ecosystems, we determined the different gene encoding enzymes associated with anaerobic pathways of energy metabolism by applying the metatranscriptomics approach. The analysis of the microbial population of hot sulfur spring revealed the presence of both aerobic and anaerobic organisms indicating dual mode of lifestyle of the community members. Proteobacteria (28.1 %) was the most dominant community. A total of 988 reads were associated with energy metabolism, out of which 33.7 % of the reads were assigned to nitrogen, sulfur, and methane metabolism based on KEGG classification. The major lineages of hot spring communities were linked with the anaerobic pathways. Different gene encoding enzymes (hao, nir, nar, cysH, cysI, acs) showed the involvement of microbial members in nitrification, denitrification, dissimilatory sulfate reduction, and methane generation. This study enhances our understanding of important gene encoding enzymes involved in energy metabolism, required for the survival and adaptation of microbial communities in the hot spring.

Metagenomics revealing molecular profiling of community structure and metabolic pathways in natural hot springs of the Sikkim Himalaya

“…The metabolic potential analysis of metagenomic sequences of Polok and Reshi inferred gene homologs mapped to different metabolic pathways such as nitrification, sulfur-oxidation, methanogenesis, carbohydrateactive enzymes, and antimicrobial compounds, etc. The operation of these pathways is related to the utilization of chemical energy into the metabolic functions of the niche microflora [40]. The microorganisms have evolved the genetic potential to metabolize the abundant chemical compounds in the thermoaquatic ecosystems for survival purposes [41,42].…”

Genome-resolved metagenomics reveals cohesive metabolic dynamics, metal resistance genes (MRGs) and biogeochemical cycling in a hot spring system

“…Analysis of nitrogen metabolic potential across MAGs revealed a higher abundance of genes involved in nitrite and nitrate reduction and ammonia assimilation. Reportedly, the anerobic respiration by chemoorganoheterotrophic bacteria utilizing nitrate (NO3 - ) as electron acceptor producing ammonia ions (NH4 + ) termed as dissimilatory nitrate reduction to ammonia (DNRA) and this process is prevalent in hot springs (Dodsworth et al ., 2011, Tripathy et al ., 2016, Alcamán-Arias et al ., 2018). So, we investigated the genes involved in dissimilatory reduction of nitrate to ammonia were (n= 181) NaNiT, NaRas, NaRper, NaRres, NaT, NiRas1, NiRas2, NiRres1, NiRres2, NiT, Reg which were found to be highly enriched in order by BU> MG> SH> KB> CS (Figure 2C).…”

Discovery of novel enzymes from extreme environments through metagenomic approaches: A mini-review

“…In the last few years, cellulases, amylases, chitinases, proteases, esterases, oxireductases, nitrilases and many other enzymes have been discovered in extreme environments as shown in Table 1. Both high throughput sequencing and PCR detection of conserved regions of enzymes can be used for the discovery of novel enzymes as a new approach these days [36,53].…”