Responses of endophytic and rhizospheric bacterial communities of salt marsh plant (Spartina alterniflora) to polycyclic aromatic hydrocarbons contamination

Abstract

Purpose Plants and their root-associated microbes play important roles in the remediation of polycyclic aromatic hydrocarbons (PAHs) present in the sediments of contaminated coastal wetlands. The detailed information about the effects of PAHs on root-associated bacterial communities could help to isolate PAH-degrading bacteria and optimize the process of phytoremediation. Materials and methods The community structures of rhizospheric (RB) and endophytic bacteria (EB) of salt marsh plant (Spartina alterniflora) grown in phenanthrene (PHE)-and pyrene (PYR)-contaminated sediments (for 70 days) were investigated using the barcoded Illumina paired-end sequencing technique. Results and discussion The diversity and community structure of EB and RB were more sensitive to PHE and PYR contamination as compared to those in the sediments. All samples were strongly clustered according to EB, RB, and sediments, suggesting the niche-specific influence of PAHs on bacterial communities. Potential PAH-degrading bacteria (Pseudomonas sp., Paenibacillus sp., and Flavobacterium sp.) in EB and RB were stimulated by PAH contamination. The results revealed an increase prevalence of specific bacteria which may be responsible for PAH degradation. PHE contamination increased the abundance of Proteobacteria in EB but decreased the number of Firmicutes, Bacteroidetes, and Chloroflexi. The numbers of Proteobacteria and Firmicutes in EB were enhanced by PYR treatment. However, both PHE and PYR treatment showed similar effects on the bacterial communities in RB.Conclusions The results suggested that PAH pollution could alter root-associated bacterial communities of S. alterniflora, whose EB might play an important role in the phytoremediation of PAH-contaminated sediments.

Heavy Metal Pollution Structures Soil Bacterial Community Dynamics in SW Spain Polluted Salt Marshes

“…They deal mainly with S. alterniflora in USA, China, and South America (Rooney-Varga et al 1997;Lovell et al 2000;Buchan et al 2003;Wang et al 2007;Nie et al 2009Nie et al , 2010Shuang et al 2009;Ferrero et al 2010;Hong et al 2014Hong et al , 2015Su et al 2016), but also Here, we use DGGE fingerprinting to study variation of bacterial populations. These PCR-dependent methods became very popular for microbial ecologists as a tool to analyze bacterial communities (Muyzer and Smalla 1998).…”

Endophytic root bacteria associated with the natural vegetation growing at the hydrocarbon-contaminated Bitumount Provincial Historic site

“…With the exception of Rhodocylales, which only represented a maximum of 0.16% in any of the root endospheres, the remaining 5 orders from their survey were present within the top 7 orders sequenced from the root endosphere of the vegetation at Bitumount. In an additional study conducted by Su et al (2015), the endophytic bacterial community of a salt marsh plant (Spartina alterniflora) grown within polycyclic aromatic hydrocarbon (PAH)-contaminated soils was identified using high-throughput sequencing. Evidence of Burkholderiales, Flavobacteriales, Bacillales, Actinomycetales, Sphingobacteriales, and Pseudomonadales were all present, all of which are associated with the degradation of hydrocarbons (Su et al 2015).…”

Responses of the Endophytic Bacterial Communities of Juncus acutus to Pollution With Metals, Emerging Organic Pollutants and to Bioaugmentation With Indigenous Strains

“…Only a few studies attempted to explore the bacterial communities associated with wetland plants and even fewer to describe the responses of such communities to mixed and highly polluted environments ( Su et al, 2015 ; Zhao et al, 2015 ; Zhang D. et al, 2016 ; Syranidou et al, 2017b ). Moreover, information relevant to the impacts of pollutants on the endophytic bacteria of wetland plants is scarce.…”