Shifts in microbial community composition in tannery-contaminated soil in response to increased gamma radiation

Abstract

Purpose Contaminated sites from man-made activities such as old-fashioned tanneries are inhabited by virulent microorganisms that exhibit more resistance against extreme and toxic environmental conditions. We investigated the effect of different Gamma radiation doses on microbial community composition in the sediment of an old-fashioned tannery. Methods Seven samples collected from the contaminated sites received different gamma radiation doses (I = 0.0, II = 5, III = 10, VI = 15, V = 20, VI = 25, and VII = 30 kGy) as an acute exposure. The shift in microbial community structure was assessed using the high throughput 454 pyrosequencing. Variations in diversity, richness, and the shift in operational taxonomic units (OTUs) were investigated using statistical analysis. Result Our results showed that the control sample (I) had the highest diversity, richness, and OTUs when compared with the irradiated samples. Species of Halocella, Parasporobacterium, and Anaerosporobacter had the highest relative abundance at the highest radiation dose of 30 kGy. Members of the Firmicutes also increased by 20% at the highest radiation dose when compared with the control sample (0.0 kGy). Representatives of Synergistetes decreased by 25% while Bacteroidetes retained a steady distribution across the range of gamma radiation intensities. Conclusion This study provides information about potential “radioresistant” and/or “radiotolerant” microbial species that are adapted to elevated level of chemical toxicity such as Cr and Sr in tannery. These species can be of a high biotechnological and environmental importance.

Taxonomic Diversity and Functional Traits of Soil Bacterial Communities under Radioactive Contamination: A Review

“…Particular studies are discussed below in the correspondent sections. Co γ-irradiation 0-30 kGy ↓ [103] Note: ↓-decrease, ↑-increase, or ↑↓-multidirectional changes in diversity. 1 -a range of values is provided for both background and contaminated sites; *-values were recalculated, assuming that the gamma detection rate is equal to 100%.…”

“…The taxonomic structure and composition of bacterial communities often change, and their diversity significantly decreases when soils are exposed to high doses of radiation [96,99,101,103]. In such cases, the eliminated species are frequently replaced by more tolerant bacteria, fungi, or microalgae [99,101].…”

“…The prevalence of Deinococcota [93,94,98,101,103] in desert bacterial communities exposed to high levels of external irradiation, often accompanied by a significant reduction in other taxonomic groups [102], represents a key characteristic of their taxonomic composition. Members of the Deinococcota phylum exhibit remarkable radiotolerance, with notable examples including the exceptionally resilient Deinococcus radiodurans, capable of surviving exposures exceeding 5 kGy [132]; Deinococcus ficus, which can withstand 3 kGy (equivalent to an absorbed dose of 18 kGy) [102]; and Deinococcus guangxiensis, exhibiting a 10% survival rate at 9.8 kGy [133].…”

Plant–microorganism–soil interaction under long-term low-dose ionizing radiation

“…Therefore, plant–microorganism–soil interaction is the main driving factor of carbon and nitrogen cycling ( Delgado-Baquerizo et al, 2016 ). Some studies have shown that a certain dose of ionizing radiation will cause changes in plant functional traits and inhibit their growth and development, changes in the content, structure, and properties of organic and inorganic substances in soil, reduction of microbial diversity, and changes in ecosystem structure and function ( Mohammad and Majed, 2019 ; Sergey et al, 2019 ; Cheptsov et al, 2021 ; Videvall et al, 2023 ). However, most of the studies on the ecological effects of ionizing radiation have mostly been carried out under laboratory conditions and usually based on a single species, excluding biological environmental factors and controlling non-biological factors, which makes these results have great limitations ( Geras'kin, 2016 ).…”

The effect of aboveground long-term low-dose ionizing radiation on soil microbial diversity and structure

“…Microorganisms develop resistance to radiation through adaptive reactions and can tolerate higher intensities of ionizing radiation over time (Fornalski et al, 2022). However, short-term and high-dose radiation has a sustained and irreversible impact on the composition, distribution, and metabolic pathways of microbial communities (Mohammad et al, 2019). The composition and functional integrity of biofilms are affected as the radiation causes single-strand or double-strand DNA breakages, denaturation of related proteins, and the reduction or inactivation of some enzymes (Romano et al, 2022).…”