Tolerance of cyanobacteria to the toxicity of BDE-47 and their removal ability.
Polybrominated diphenyl ethers are ubiquitous and toxic contaminants in aquatic environments. The effect of polybrominated diphenyl ether BDE-47 on five species of cyanobacteria, along with their removal ability was investigated. Four species, namely Synechocystis sp., Oscillatoria planctonica, Microcystis flos-aquae and Nostoc sp., were exposed to BDE-47 at concentrations ranging from 0.05 to 1.0 mg L-1for 14 days, while the exposure time for Pseudanabaena sp. was 30 days. The first four species were very tolerant to BDE-47 while growth and photosynthesis of Pseudanabaena were significantly inhibited by BDE-47 at concentrations over 0.1 mg L-1. However, this species could recover from the toxicity of high concentrations of BDE-47 after 30 days of exposure, indicating the development of some "resistance" after pre-exposure to 1.0 mg L-1BDE-47. The "resistant" cells had a higher growth rate, photosynthesis and glutathione S-transferase activity than normal Pseudanabaena cells. The sensitivity of Pseudanabaena to BDE-47 toxicity was affected by its initial filament density, with cultures having a low filament density (2.3 × 106filaments mL-1) being up to 14-15 times more sensitive than cultures with a high filament density (13 × 106filaments mL-1). All cyanobacteria could remove 70-82% of BDE-47 in their media, with more than 60% of BDE-47 accumulated in cells. This is the first study showing the high tolerance of different cyanobacteria species to BDE-47 toxicity and their removal ability. The study also revealed that the sensitive Pseudanabaena could acquire a "resistance" to BDE-47, which was transferred to the next generation.
Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Kowloon, Hong Kong, China.
Annie
A
Chalifour
Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Kowloon, Hong Kong, China; State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Kowloon, Hong Kong, China. Electronic address: bhntam@cityu.edu.hk.
Nora Fung-Yee
NF
Tam
D002734:Chlorophyll / Q000378:metabolism; D000458:Cyanobacteria / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D004361:Drug Tolerance; D005982:Glutathione Transferase; D055768:Halogenated Diphenyl Ethers / Q000032:analysis / Q000302:isolation & purification* / Q000633:toxicity*; D008055:Lipids / Q000032:analysis; D010788:Photosynthesis / Q000187:drug effects
D055768:Halogenated Diphenyl Ethers; D008055:Lipids; C511295:2,2',4,4'-tetrabromodiphenyl ether; D002734:Chlorophyll; D005982:Glutathione Transferase
Cyanobacteria; F(V)/F(M); Organic contaminant; Polybrominated diphenyl ethers; Toxicity mechanism