Dredged Material from Harmful Algal Bloom Affected Lake Erie harbors: Microbiome, Resistome, and Cyanotoxins
Start Date
23-5-2022 5:45 PM
End Date
23-5-2022 7:00 PM
Abstract
Dredging is a common practice for the maintenance of harbors by removing the built-up sediments. Land application has been proposed as an environmental and economic-friendly way to use dredged material (DM). However, DM can be a reservoir of various pollutants, among which antibiotic resistance bacteria (ARB) and cyanotoxin are understudied. The discharge of human and agricultural wastewater can spur both algal bloom and ARB in surface water. Given this, DM must be better understood before land application.
This study characterized DMs from six harbors located in the southwest shore of Lake Erie. The profile of cyanobacteria communities and resistome was depicted with Nanopore sequencing. Dominated toxic cyanobacteria genera in DM are Microcystis, Planktothrix, Aphanizomenon, and Synechococcus. Microcystin (MC)-producing Microcystis is the major toxin producer in most DMs, which significantly correlated with the total cyanobacteria and MC concentration (p < 0.000). In line with the bloom spatial distribution in Lake Erie, from west to east, MC and toxic cyanobacteria concentration in DM decreased significantly but remained. Toledo DM has the highest MC concentration while saxitoxin and anatoxin producers were also detected. Moreover, clinically relevant AR genes like fluoroquinolone, aminoglycoside, and tetracycline resistance genes were identified with various pathogenic hosts.
Dredged Material from Harmful Algal Bloom Affected Lake Erie harbors: Microbiome, Resistome, and Cyanotoxins
Dredging is a common practice for the maintenance of harbors by removing the built-up sediments. Land application has been proposed as an environmental and economic-friendly way to use dredged material (DM). However, DM can be a reservoir of various pollutants, among which antibiotic resistance bacteria (ARB) and cyanotoxin are understudied. The discharge of human and agricultural wastewater can spur both algal bloom and ARB in surface water. Given this, DM must be better understood before land application.
This study characterized DMs from six harbors located in the southwest shore of Lake Erie. The profile of cyanobacteria communities and resistome was depicted with Nanopore sequencing. Dominated toxic cyanobacteria genera in DM are Microcystis, Planktothrix, Aphanizomenon, and Synechococcus. Microcystin (MC)-producing Microcystis is the major toxin producer in most DMs, which significantly correlated with the total cyanobacteria and MC concentration (p < 0.000). In line with the bloom spatial distribution in Lake Erie, from west to east, MC and toxic cyanobacteria concentration in DM decreased significantly but remained. Toledo DM has the highest MC concentration while saxitoxin and anatoxin producers were also detected. Moreover, clinically relevant AR genes like fluoroquinolone, aminoglycoside, and tetracycline resistance genes were identified with various pathogenic hosts.