Interactive effects of hypoxia and polybrominated diphenyl ethers (PBDEs) on microbial community assembly in surface marine sediments

• Published in: Marine pollution bulletin 2014-08, Vol.85 (2), p.400-409
• Main Authors: Chan, Yuki, Li, Amy, Gopalakrishnan, Singaram, Shin, Paul K.S., Wu, Rudolf S.S., Pointing, Stephen B., Chiu, Jill M.Y.
• Format: Article
• Language: English
• Subjects: Anaerobiosis; Animal and plant ecology; Animal, plant and microbial ecology; Applied ecology; Bacteria - classification; Bacteria - drug effects; Bacteria - metabolism; Bacterial communities; Biological and medical sciences; Ecotoxicology, biological effects of pollution; Environmental Monitoring; Flame Retardants - analysis; Flame Retardants - pharmacology; Fundamental and applied biological sciences. Psychology; Geologic Sediments - chemistry; Geologic Sediments - microbiology; Halogenated Diphenyl Ethers - analysis; Halogenated Diphenyl Ethers - pharmacology; Hong Kong; Hypoxia; Marine; Marine and brackish environment; Marine sediment; Microbial ecology; Oxygen - analysis; Oxygen - metabolism; Phylogeny; Polybrominated diphenyl ethers; Sea water ecosystems; Synecology; Various environments (extraatmospheric space, air, water)
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2014.04.052

•Both BDE47 and hypoxia and alone reduced the species and genetic diversity.•BDE47 selected certain bacterial species and resulted in major community shifts.•Hypoxia changed the relative abundances of taxa.•There were interactive effects of BDE47 and hypoxia on bacterial communities. Hypoxia alters the oxidation–reduction balance and the biogeochemical processes in sediments, but little is known about its impacts on the microbial community that is responsible for such processes. In this study, we investigated the effects of hypoxia and the ubiquitously dispersed flame-retardant BDE47 on the bacterial communities in marine surface sediments during a 28-days microcosm experiment. Both hypoxia and BDE47 alone significantly altered the bacterial community and reduced the species and genetic diversity. UniFrac analysis revealed that BDE47 selected certain bacterial species and resulted in major community shifts, whereas hypoxia changed the relative abundances of taxa, suggesting slower but nonetheless significant community shifts. These two stressors targeted mostly different taxa, but they both favored Bacteroidetes and suppressed Gammaproteobacteria. Importantly, the impacts of BDE47 on bacterial communities were different under hypoxic and normoxic conditions, highlighting the need to consider risk assessments for BDE47 in a broader context of interaction with hypoxia.