Wang Ya, Zhang Chun-Hua, Wang Shu, Shen Lian-Yu, Ge Ying
College of Resources and Environmental Sciences, Jiangsu Provincial Key Laboratory of Marine Biology, Nanjing Agricultural University, Nanjing 210095, China.
Demonstration Laboratory of Elements and Life Science, Laboratory Centre of Life Science, Nanjing Agricultural University, Nanjing 210095, China.
Huan Jing Ke Xue. 2013 Nov;34(11):4257-65.
Algae and bacteria are usually symbiotic in the environment. The algae-bacteria consortia have a good prospect in the remediation of polluted environment. In this study, we isolated a bacterium from nonaxenic Dunaliella salina and identified it as Bacillus solisalsi using 16S rRNA sequence analysis. The uptake, adsorption and transformation of As by the nonaxenic D. salina and the concentration and speciation of As in the culture solution were determined after 13 days exposure to various concentrations of As(III) and As( V). The results showed that D. salina had a high As tolerance. When the algae was exposed to 250 micromol x L(-1) and 500 micromol x L(-1) arsenite, As accumulations were 3.78 g x kg(-1) and 4.56 g x kg(-1), respectively, but the As removal from the solution was 7.9% - 8.3%. B. solisalsi did not show a strong ability to clean up As either (6.1%-19.9% removal rate). The consortia of D. salina and B. solisalsi showed a higher As removal ability. Moreover, 0.99-2.79 g x kg(-1) and 1.22-3.46 g x kg(-1) As were absorbed when exposed to 25-100 micromol x L(-1) and 25-500 micromol x L(-1) As(III) and As(V), respectively. More than 54.3% of As were taken away by the consortia from the solution under the exposure of 25-100 micromol x L(-1) As(III) and As(V). Various pathways of As detoxification were identified for the nonaxenic D. salina: As(III) oxidation, As(V) reduction, As(III) methylation, and efflux of As from cells.
