Soil microbiota and microarthropod communities in oil contaminated sites in the European Subarctic

Abstract

The present comprehensive study aimed to estimate the aftermath of oil contamination and the efficacy of removing the upper level of polluted soil under the conditions of the extreme northern taiga of northeastern European Russia. Soil samples from three sites were studied. Two sites were contaminated with the contents of a nearby sludge collector five years prior to sampling. The highly contaminated upper soil level was removed from one of them. The other was left for self-restoration. A chemical analysis of the soils was conducted, and changes in the composition of the soil zoocoenosis and bacterial and fungal microbiota were investigated. At both contaminated sites, a decrease in the abundance and taxonomic diversity of indicator groups of soil fauna, oribatid mites and collembolans compared to the background site were found. The pioneer eurytopic species Oppiella nova, Proisotoma minima and Xenyllodes armatus formed the basis of the microarthropod populations in the contaminated soil. A complete change in the composition of dominant taxonomic units was observed in the microbiota, both the bacterial and fungal communities. There was an increase in the proportion of representatives of Proteobacteria and Actinobacteria in polluted soils compared to the background community. Hydrocarbon-degrading bacteria—Alcanivorax, Rhodanobacter ginsengisoli, Acidobacterium capsulatum, and Acidocella—and fungi—Amorphotheca resinae abundances greatly increased in oil-contaminated soil. Moreover, among both bacteria and fungi, a sharp increase in the abundance of uncultivated organisms that deserve additional attention as potential oil degraders or organisms with a high resistance to oil contamination were observed. The removal of the upper soil level was partly effective in terms of decreasing the oil product concentration (from approximately 21 to 2.6 g/kg of soil) and preventing a decrease in taxonomic richness but did not prevent alterations in the composition of the microbiota or zoocoenosis.

Soil Microbiome in Conditions of Oil Pollution of Subarctic Ecosystems

“…Our research indicates that the composition of microbial communities analyzed at the dominant phyla level exhibited similarities to those observed in other sites contaminated with oil [17]. Significant differences in the microbial community structure were observed between the experimental sites and the reference site (Figures 8 and 13).…”

“…A long-term monitoring study was carried out to analyze the effects of various bioremediation methods on the restoration of biotic and abiotic components in contaminated soil [ 10 , 16 ]. Additionally, research has begun to evaluate the microbial diversity of oil-contaminated soils using metagenomic analysis [ 17 ]. Currently, active research is being conducted on soil microbial diversity based on metagenomic analysis [ 18 ].…”

Large-scale experimental warming reduces soil faunal biodiversity through peatland drying

“…Further, two parthenogenetic species of oribatid mites (E. mahunkai and Oppiella nova (Oudemans, 1902)) were associated with soil temperature as a variable in the DB-RDA analysis (see Supplementary Table S1 for list of species identified as asexual). Oppiella nova is a cosmopolitan species found in almost all habitats sampled and sometimes associated with disturbance (Melekhina et al, 2021), while E. mahunkai is a peatland specialist (Behan-Pelletier and Lindo, 2023). Markkula et al (2019) found that year-round warming, as with the SPRUCE experiment, had no effect on total abundance of oribatids, possibly because of contrasting effects of warming in summer versus winter seasons.…”

Phylogenomic analysis of the genus Alcanivorax: proposal for division of this genus into the emended genus Alcanivorax and two novel genera Alloalcanivorax gen. nov. and Isoalcanivorax gen. nov.

“…The genus Alcanivorax is an ecologically significant hydrocarbonoclastic group of bacteria. Its members are capable of degrading alkane and other derived hydrocarbon compounds as carbon and energy sources [1]. The genus Alcanivorax comes under the family Alcanivoraceae along with the two other genera of Ketobacter [2] and Pelagibaculum [3].…”