Department of Chemistry, Trent University, 1600 West Bank Drive, Peterborough, ON, Canada.
Environ Sci Technol. 2011 Mar 15;45(6):2165-71. doi: 10.1021/es103337p. Epub 2011 Feb 22.
The common green fresh water algae Chlorella vulgaris was exposed to starting concentrations of 10 μg/L selenium in the form of selenate, selenite, or selenocyanate (SeCN(-)) for nine days in 10% Bold's basal medium. Uptake of selenate was more pronounced than that of selenite, and there was very little uptake of selenocyanate. Upon uptake of selenate, significant quantities of selenite and selenocyanate were produced by the algae and released back into the growth medium; no selenocyanate was released after selenite uptake. Release of the reduced metabolites after selenate exposure appeared to coincide with increasing esterase activity in solution, indicating that cell death (lysis) was the primary emission pathway. This is the first observation of biotic formation of selenocyanate and its release into waters from a nonindustrial source. The potential environmental implications of this laboratory observation are discussed with respect to the fate of selenium in impacted aquatic systems, the ecotoxicology of selenium bioaccumulation, and the interpretation of environmental selenium speciation data generated, using methods incapable of positively identifying reduced inorganic selenium species, such as selenocyanate.
将普通的淡水绿藻小球藻在 10% Bold 基本培养基中用硒酸盐、亚硒酸盐或硒氰酸盐（SeCN(-)）以 10μg/L 的起始浓度暴露 9 天。硒酸盐的摄取比亚硒酸盐明显，而硒氰酸盐的摄取很少。在摄取硒酸盐后，藻类会产生大量的亚硒酸盐和硒氰酸盐，并将其释放回生长培养基中；亚硒酸盐摄取后不会释放硒氰酸盐。硒酸盐暴露后还原代谢物的释放似乎与溶液中酯酶活性的增加同时发生，表明细胞死亡（裂解）是主要的排放途径。这是首次观察到非工业来源的生物形成硒氰酸盐及其释放到水中。本文讨论了这一实验室观察结果对受影响水生系统中硒命运、硒生物积累的生态毒理学以及使用无法正识别还原无机硒物种（如硒氰酸盐）的方法生成的环境硒形态数据的解释的潜在环境影响。
