Remarkable shift in structural and functional properties of an animal charcoal-polluted soil accentuated by inorganic nutrient amendment

Abstract Background Soils polluted with animal charcoal from skin and hide cottage industries harbour extremely toxic and carcinogenic hydrocarbon pollutants and thus require a bio-based eco-friendly strategy for their depuration. The effects of carbon-free mineral medium (CFMM) amendment on hydrocarbon degradation and microbial community structure and function in an animal charcoal-polluted soil was monitored for 6 weeks in field moist microcosms consisting of CFMM-treated soil (FN4) and an untreated control (FN1). Hydrocarbon degradation was monitored using gas chromatography-flame ionization detector (GC-FID), and changes in microbial community structure were monitored using Kraken, while functional annotation of putative open reading frames (ORFs) was done using KEGG KofamKOALA and NCBI’s conserved domain database (CDD). Results Gas chromatographic analysis of hydrocarbon fractions revealed the removal of 84.02% and 82.38% aliphatic and 70.09% and 70.14% aromatic fractions in FN4 and FN1 microcosms in 42 days. Shotgun metagenomic analysis of the two metagenomes revealed a remarkable shift in the microbial community structure. In the FN4 metagenome, 92.97% of the population belong to the phylum Firmicutes and its dominant representative genera Anoxybacillus (64.58%), Bacillus (21.47%) and Solibacillus (2.39%). In untreated FN1 metagenome, the phyla Proteobacteria (56.12%), Actinobacteria (23.79%) and Firmicutes (11.20%), and the genera Xanthobacter (9.73%), Rhizobium (7.49%) and Corynebacterium (7.35%), were preponderant. Functional annotation of putative ORFs from the two metagenomes revealed the detection of degradation genes for aromatic hydrocarbons, benzoate, xylene, chlorocyclohexane/chlorobenzene, toluene and several others in FN1 metagenome. In the FN4 metagenome, only seven hydrocarbon degradation genes were detected. Conclusion This study revealed that though CFMM amendment slightly increases the rate of hydrocarbon degradation, it negatively impacts the structural and functional properties of the animal charcoal-polluted soil. It also revealed that intrinsic bioremediation of the polluted soil could be enhanced via addition of water and aeration.

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Remarkable Shift In Structural And Functional Properties of An Animal Charcoal Polluted Soil Accentuated By Inorganic Nutrients Amendment

10.21203/rs.3.rs-38325/v1 ◽

2020 ◽

Author(s):

Lateef Salam ◽

Oluwafemi S. Obayori

Keyword(s):

Community Structure ◽

Microbial Community ◽

Functional Properties ◽

Microbial Community Structure ◽

Polluted Soil ◽

Hydrocarbon Degradation ◽

Intrinsic Bioremediation ◽

Structural And Functional Properties ◽

And Function ◽

Animal Charcoal

Abstract The effects of carbon-free mineral medium (CFMM) amendment on hydrocarbon degradation and microbial community structure and function in an animal charcoal polluted soil was monitored for six weeks in field moist microcosms consisting of CFMM treated soil (FN4) and an untreated control (FN1). Gas chromatographic analysis of hydrocarbon fractions revealed the removal 84.02% and 82.38% and 70.09% and 70.14% aliphatic and aromatic fractions in FN4 and FN1 microcosms in 42 days. Shotgun metagenomic analysis of the two metagenomes revealed a remarkable shift in the microbial community structure of FN4 metagenome with 92.97% of the population belonging to the phylum Firmicutes and its dominant representative genera Anoxybacillus (64.58%), Bacillus (21.47%) and Solibacillus (2.39%). In untreated FN1 metagenome, the phyla Proteobacteria (56.12%), Actinobacteria (23.79%), Firmicutes (11.20%); and the genera Xanthobacter (9.73%), Rhizobium (7.49%) and Corynebacterium (7.35%) were preponderant. Functional annotation of putative ORFs from the two metagenomes revealed the detection of degradation genes for benzoate (pcaD, mhpF, aliB, benD-xylL, benC-xylZ, badH, had, dmpD, ligC, CMLE, pcaL, acd), xylene (mhpF, benD-xylL, benC-xylZ, dmpD, cymB, cmtB), chlorocyclohexane/chlorobenzene (dehH, dhaA, linC, linX, pcpC), toluene (bbsG, bbsC, bbsD, tsaC1), and several others in FN1 metagenome. In FN4 metagenome, only seven hydrocarbon degradation genes namely dmpH, mhpD, bphH, nemA and three others were detected. This study has revealed that CFMM amendment negatively impacts the structural and functional properties of the animal charcoal polluted soil. It also revealed that intrinsic bioremediation of the polluted soil could be enhanced via addition of water and aeration.

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Microbial community structure and functional properties in permanently and seasonally flooded areas in Poyang Lake

Scientific Reports ◽

10.1038/s41598-020-61569-z ◽

2020 ◽

Vol 10 (1) ◽

Cited By ~ 2

Author(s):

Yang Liu ◽

Ze Ren ◽

Xiaodong Qu ◽

Min Zhang ◽

Yang Yu ◽

...

Keyword(s):

Community Structure ◽

Microbial Community ◽

Functional Properties ◽

Microbial Community Structure ◽

Poyang Lake ◽

Seasonally Flooded ◽

Flooded Areas

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Microbial Community Dynamics during Biodegradation of Crude Oil and Its Response to Biostimulation in Svalbard Seawater at Low Temperature

Microorganisms ◽

10.3390/microorganisms9122425 ◽

2021 ◽

Vol 9 (12) ◽

pp. 2425

Author(s):

Hiie Nõlvak ◽

Nga Phuong Dang ◽

Marika Truu ◽

Angela Peeb ◽

Kertu Tiirik ◽

...

Keyword(s):

Community Structure ◽

Microbial Community ◽

Crude Oil ◽

Microbial Community Structure ◽

Community Dynamics ◽

Oil Spills ◽

Hydrocarbon Degradation ◽

Taxonomic Assignment ◽

Metabolic Potential ◽

Microbial Community Dynamics

The development of oil exploration activities and an increase in shipping in Arctic areas have increased the risk of oil spills in this cold marine environment. The objective of this experimental study was to assess the effect of biostimulation on microbial community abundance, structure, dynamics, and metabolic potential for oil hydrocarbon degradation in oil-contaminated Arctic seawater. The combination of amplicon-based and shotgun sequencing, together with the integration of genome-resolved metagenomics and omics data, was applied to assess microbial community structure and metabolic properties in naphthenic crude oil-amended microcosms. The comparison of estimates for oil-degrading microbial taxa obtained with different sequencing and taxonomic assignment methods showed substantial discrepancies between applied methods. Consequently, the data acquired with different methods was integrated for the analysis of microbial community structure, and amended with quantitative PCR, producing a more objective description of microbial community dynamics and evaluation of the effect of biostimulation on particular microbial taxa. Implementing biostimulation of the seawater microbial community with the addition of nutrients resulted in substantially elevated prokaryotic community abundance (103-fold), a distinctly different bacterial community structure from that in the initial seawater, 1.3-fold elevation in the normalized abundance of hydrocarbon degradation genes, and 12% enhancement of crude oil biodegradation. The bacterial communities in biostimulated microcosms after four months of incubation were dominated by Gammaproteobacterial genera Pseudomonas, Marinomonas, and Oleispira, which were succeeded by Cycloclasticus and Paraperlucidibaca after eight months of incubation. The majority of 195 compiled good-quality metagenome-assembled genomes (MAGs) exhibited diverse hydrocarbon degradation gene profiles. The results reveal that biostimulation with nutrients promotes naphthenic oil degradation in Arctic seawater, but this strategy alone might not be sufficient to effectively achieve bioremediation goals within a reasonable timeframe.

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