Temperature - A critical abiotic paradigm that governs bacterial heterogeneity in natural ecological system

Santosh Kumar; Ishfaq Nabi Najar; Prayatna Sharma; Sonia Tamang; Krishnendu Mondal; Sayak Das; Mingma Thundu Sherpa; Nagendra Thakur

doi:10.1016/j.envres.2023.116547

Temperature - A critical abiotic paradigm that governs bacterial heterogeneity in natural ecological system

Environ Res. 2023 Oct 1:234:116547. doi: 10.1016/j.envres.2023.116547. Epub 2023 Jul 6.

Authors

Santosh Kumar¹, Ishfaq Nabi Najar¹, Prayatna Sharma¹, Sonia Tamang¹, Krishnendu Mondal², Sayak Das³, Mingma Thundu Sherpa¹, Nagendra Thakur⁴

Affiliations

¹ Department of Microbiology, School of Life Sciences, Sikkim University, Gangtok, 737102, Sikkim, India.
² Department of Microbiology, Vidyasagar University, Midnapore, 721102, India.
³ Department of Life Science & Bioinformatics, HK School of Life Sciences, Assam University, Silchar, 788011, Assam, India.
⁴ Department of Microbiology, School of Life Sciences, Sikkim University, Gangtok, 737102, Sikkim, India. Electronic address: nthakur@cus.ac.in.

PMID: 37422118
DOI: 10.1016/j.envres.2023.116547

Abstract

A baseline data has been presented here to prove that among the abiotic factors, temperature is the most critical factor that regulates and governs the bacterial diversity in a natural ecosystem. Present study in Yumesamdong hot springs riverine vicinity (Sikkim), parades a gamut of bacterial communities in it and hosts them from semi-frigid region (- 4-10 °C) to fervid region (50-60 °C) via an intermediate region (25-37 °C) within the same ecosystem. This is an extremely rare intriguing natural ecosystem that has no anthropogenic disturbances nor any artificial regulation of temperature. We scanned the bacterial flora through both the culture-dependent and culture-independent techniques in this naturally complex thermally graded habitat. High-throughput sequencing gave bacterial and archaeal phyla representatives of over 2000 species showcasing their biodiversity. Proteobacteria, Firmicutes, Bacteroidetes and Chloroflexi were the predominant phyla. A concave down-curve significance was found in temperature-abundance correlation as the number of microbial taxa decreased when the temperature increased from warm (35 °C) to hot (60 °C). Firmicutes showed significant linear increase from cold to hot environment whereas Proteobacteria followed the opposite trend. No significant correlation was observed for physicochemical parameters against the bacterial diversity. However, only temperature has shown significant positive correlation to the predominant phyla at their respective thermal gradients. The antibiotic resistance patterns correlated with temperature gradient where the prevalence of antibiotic resistance was higher in case of mesophiles than that of psychrophiles and there was no resistance in thermophiles. The antibiotic resistant genes obtained were solely from mesophiles as it conferred high resistance at mesophilic conditions enabling them to adapt and metabolically compete for survival. Our study concludes that the temperature is a major factor that plays a significant contribution in shaping the bacterial community structure in any thermal gradient edifice.

Keywords: Adaptation; Bio-diversity; Mesophiles; Psychrophiles; Temperature; Thermophiles.

MeSH terms

Archaea / genetics
Bacteria* / genetics
Biodiversity
Ecosystem*
Phylogeny
RNA, Ribosomal, 16S / genetics
Temperature

Substances

RNA, Ribosomal, 16S