scholarly journals How the Soil Microbial Communities and Activities Respond to Long-Term Heavy Metal Contamination in Electroplating Contaminated Site

2021 ◽  
Vol 9 (2) ◽  
pp. 362 ◽  
Author(s):  
Wen-Jing Gong ◽  
Zi-Fan Niu ◽  
Xing-Run Wang ◽  
He-Ping Zhao
Keyword(s):  
Heavy Metal ◽  
Microbial Communities ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Soil Microbial Communities ◽  
Contaminated Site ◽  
Rrna Gene ◽  
Soil Microbial ◽  
Cu And Zn

The effects of long-term heavy metal contamination on the soil biological processes and soil microbial communities were investigated in a typical electroplating site in Zhangjiakou, China. It was found that the soil of the electroplating plant at Zhangjiakou were heavily polluted by Cr, Cr (VI), Ni, Cu, and Zn, with concentrations ranged from 112.8 to 9727.2, 0 to 1083.3, 15.6 to 58.4, 10.8 to 510.0 and 69.6 to 631.6 mg/kg, respectively. Soil urease and phosphatase activities were significantly inhibited by the heavy metal contamination, while the microbial biomass carbon content and the bacterial community richness were much lower compared to noncontaminated samples, suggesting that the long-term heavy metal contamination had a severe negative effect on soil microorganisms. Differently, soil dehydrogenase was promoted in the presence of Chromate compared to noncontaminated samples. This might be due to the enrichment of Sphingomonadaceae, which have been proven to be able to secrete dehydrogenase. The high-throughput sequencing of the 16S rRNA gene documented that Proteobacteria, Actinobacteria, and Chloroflexi were the dominant bacterial phyla in the contaminated soil. The Spearman correlation analysis showed the Methylobacillus, Muribaculaceae, and Sphingomonadaceae were able to tolerate high concentrations of Cr, Cr (VI), Cu, and Zn, indicating their potential in soil remediation.

scholarly journals Long-Term Drought and Warming Alter Soil Bacterial and Fungal Communities in an Upland Heathland

Ecosystems ◽  
2021 ◽  
Author(s):  
Fiona M. Seaton ◽  
Sabine Reinsch ◽  
Tim Goodall ◽  
Nicola White ◽  
Davey L. Jones ◽  
...  
Keyword(s):  
Climate Change ◽  
Microbial Communities ◽  
Soil Microbial Communities ◽  
Fungal Communities ◽  
Its2 Region ◽  
Rrna Gene ◽  
Summer Drought ◽  
Soil Microbial ◽  
Soil Bacterial

AbstractThe response of soil microbial communities to a changing climate will impact global biogeochemical cycles, potentially leading to positive and negative feedbacks. However, our understanding of how soil microbial communities respond to climate change and the implications of these changes for future soil function is limited. Here, we assess the response of soil bacterial and fungal communities to long-term experimental climate change in a heathland organo-mineral soil. We analysed microbial communities using Illumina sequencing of the 16S rRNA gene and ITS2 region at two depths, from plots undergoing 4 and 18 years of in situ summer drought or warming. We also assessed the colonisation of Calluna vulgaris roots by ericoid and dark septate endophytic (DSE) fungi using microscopy after 16 years of climate treatment. We found significant changes in both the bacterial and fungal communities in response to drought and warming, likely mediated by changes in soil pH and electrical conductivity. Changes in the microbial communities were more pronounced after a longer period of climate manipulation. Additionally, the subsoil communities of the long-term warmed plots became similar to the topsoil. Ericoid mycorrhizal colonisation decreased with depth while DSEs increased; however, these trends with depth were removed by warming. We largely ascribe the observed changes in microbial communities to shifts in plant cover and subsequent feedback on soil physicochemical properties, especially pH. Our results demonstrate the importance of considering changes in soil microbial responses to climate change across different soil depths and after extended periods of time.

scholarly journals Lateral Gene Transfer in a Heavy Metal-Contaminated-Groundwater Microbial Community

mBio ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Christopher L. Hemme ◽  
Stefan J. Green ◽  
Lavanya Rishishwar ◽  
Om Prakash ◽  
Angelica Pettenato ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Microbial Community ◽  
Gene Transfer ◽  
Microbial Communities ◽  
Lateral Gene Transfer ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Contaminated Groundwater ◽  
Rrna Gene ◽  
Changing Environments

ABSTRACT Unraveling the drivers controlling the response and adaptation of biological communities to environmental change, especially anthropogenic activities, is a central but poorly understood issue in ecology and evolution. Comparative genomics studies suggest that lateral gene transfer (LGT) is a major force driving microbial genome evolution, but its role in the evolution of microbial communities remains elusive. To delineate the importance of LGT in mediating the response of a groundwater microbial community to heavy metal contamination, representative Rhodanobacter reference genomes were sequenced and compared to shotgun metagenome sequences. 16S rRNA gene-based amplicon sequence analysis indicated that Rhodanobacter populations were highly abundant in contaminated wells with low pHs and high levels of nitrate and heavy metals but remained rare in the uncontaminated wells. Sequence comparisons revealed that multiple geochemically important genes, including genes encoding Fe 2+ /Pb 2+ permeases, most denitrification enzymes, and cytochrome c 553 , were native to Rhodanobacter and not subjected to LGT. In contrast, the Rhodanobacter pangenome contained a recombinational hot spot in which numerous metal resistance genes were subjected to LGT and/or duplication. In particular, Co 2+ /Zn 2+ /Cd 2+ efflux and mercuric resistance operon genes appeared to be highly mobile within Rhodanobacter populations. Evidence of multiple duplications of a mercuric resistance operon common to most Rhodanobacter strains was also observed. Collectively, our analyses indicated the importance of LGT during the evolution of groundwater microbial communities in response to heavy metal contamination, and a conceptual model was developed to display such adaptive evolutionary processes for explaining the extreme dominance of Rhodanobacter populations in the contaminated groundwater microbiome. IMPORTANCE Lateral gene transfer (LGT), along with positive selection and gene duplication, are the three main mechanisms that drive adaptive evolution of microbial genomes and communities, but their relative importance is unclear. Some recent studies suggested that LGT is a major adaptive mechanism for microbial populations in response to changing environments, and hence, it could also be critical in shaping microbial community structure. However, direct evidence of LGT and its rates in extant natural microbial communities in response to changing environments is still lacking. Our results presented in this study provide explicit evidence that LGT played a crucial role in driving the evolution of a groundwater microbial community in response to extreme heavy metal contamination. It appears that acquisition of genes critical for survival, growth, and reproduction via LGT is the most rapid and effective way to enable microorganisms and associated microbial communities to quickly adapt to abrupt harsh environmental stresses.

scholarly journals Activity and functional diversity of microbial communities in long-term hydrocarbon and heavy metal contaminated soils

2016 ◽  
Vol 42 (4) ◽  
pp. 3-11 ◽  
Author(s):  
Anna Markowicz ◽  
Grażyna Płaza ◽  
Zofia Piotrowska-Seget
Keyword(s):  
Heavy Metal ◽  
Microbial Communities ◽  
Functional Diversity ◽  
Contaminated Soils ◽  
Coke Plant ◽  
Soil Microbial Communities ◽  
Hydrocarbon Contamination ◽  
Soil Microbial ◽  
Polycyclic Aromatic

Abstract The impacts of long-term polycyclic aromatic hydrocarbons (PAHs) and heavy metal pollution on soil microbial communities functioning were studied in soils taken from an old coke plant. The concentrations of PAHs in the tested soils ranged from 171 to 2137 mg kg-1. From the group of tested heavy metals, concentrations of lead were found to be the highest, ranging from 57 to 3478 mg kg-1, while zinc concentrations varied from 247 to 704 mg kg-1 and nickel from 10 to 666 mg kg-1. High dehydrogenase, acid and alkaline phosphatase activities were observed in the most contaminated soil. This may indicate bacterial adaptation to long-term heavy metal and hydrocarbon contamination. However, the Community Level Physiological Profiles (CLPPs) analysis showed that the microbial functional diversity was reduced and influenced to a higher extent by some metals (Pb, Ni), moisture and conductivity than by PAHs.

Sign in / Sign up

Export Citation Format

Share Document