TY - JOUR
T1 - Frequencies of heavy metal resistance are associated with land cover type in the Upper Mississippi River
AU - Staley, Christopher
AU - Johnson, Dylan
AU - Gould, Trevor J.
AU - Wang, Ping
AU - Phillips, Jane
AU - Cotner, James B.
AU - Sadowsky, Michael J.
N1 - Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2015/4/1
Y1 - 2015/4/1
N2 - Taxonomic compositions of freshwater bacterial communities have been well-characterized via metagenomic and amplicon-based approaches, especially next-generation sequencing. However, functional diversity of these communities remains less well-studied. Various anthropogenic sources are known to impact the bacterial community composition in freshwater riverine systems and potentially alter functional diversity. In this study, high-throughput functional screening of large (~10,000 clones) fosmid libraries representing communities in the Upper Mississippi River revealed low frequencies of resistance to heavy metals in the following order: Mn2+>Cr3+>Zn2+>Cd2+>Hg2+. No resistance to Cu2+ was detected. Significant, but weak, correlations were observed between resistance frequencies of Cd and Cr with developed land cover (r2=0.08, P=0.016 and r=0.07, P=0.037, respectively). While discriminant function analyses further supported these associations, redundancy analysis further indicated associations with forested land cover and greater resistance to Hg and Zn. Nutrient and metal ion concentrations and abundances of bacterial orders were poorly correlated with heavy metal resistance, except for an association of Pseudomonadales abundance and resistance to Hg and Zn. Taken together, results of this study suggest that allochthonous bacteria contributed from specific land cover types influence the patterns of metal resistance throughout this river.
AB - Taxonomic compositions of freshwater bacterial communities have been well-characterized via metagenomic and amplicon-based approaches, especially next-generation sequencing. However, functional diversity of these communities remains less well-studied. Various anthropogenic sources are known to impact the bacterial community composition in freshwater riverine systems and potentially alter functional diversity. In this study, high-throughput functional screening of large (~10,000 clones) fosmid libraries representing communities in the Upper Mississippi River revealed low frequencies of resistance to heavy metals in the following order: Mn2+>Cr3+>Zn2+>Cd2+>Hg2+. No resistance to Cu2+ was detected. Significant, but weak, correlations were observed between resistance frequencies of Cd and Cr with developed land cover (r2=0.08, P=0.016 and r=0.07, P=0.037, respectively). While discriminant function analyses further supported these associations, redundancy analysis further indicated associations with forested land cover and greater resistance to Hg and Zn. Nutrient and metal ion concentrations and abundances of bacterial orders were poorly correlated with heavy metal resistance, except for an association of Pseudomonadales abundance and resistance to Hg and Zn. Taken together, results of this study suggest that allochthonous bacteria contributed from specific land cover types influence the patterns of metal resistance throughout this river.
KW - Amplicon sequencing
KW - Bacterial community structure
KW - Fosmid library
KW - Functional analyses
KW - Heavy metal resistance
KW - Mississippi River
UR - http://www.scopus.com/inward/record.url?scp=84920614249&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84920614249&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2014.12.069
DO - 10.1016/j.scitotenv.2014.12.069
M3 - Article
C2 - 25569582
AN - SCOPUS:84920614249
SN - 0048-9697
VL - 511
SP - 461
EP - 468
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -