Chen Xueqing, Pei Yuansheng
The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing 100875, China.
The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing 100875, China.
Ecotoxicol Environ Saf. 2016 Oct;132:353-9. doi: 10.1016/j.ecoenv.2016.06.024. Epub 2016 Jun 28.
Sodium pentaborate pentahydrate (SPP) is a rare mineral. In this study, SPP was synthesized from boric acid and borax through low-temperature crystallization, and its effects on the growth of the alga, Chlorella vulgaris (C. vulgaris) were assessed. The newly synthesized SPP was characterized by chemical analysis, X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, and differential thermal analysis. The changes in C. vulgaris growth, chlorophyll content, and enzyme activities upon exposure to SPP for 168h were evaluated. Results showed that SPP treatment was detrimental to C. vulgaris growth during the first 24-120h of exposure. The harmful effects, however, diminished over time (168h), even at an effective medium concentration of 226.37mg BL(-1) (the concentration of boron applied per liter of culture medium). A similar trend was observed for chlorophyll content (chlorophyll a and b) and indicated that the photosynthesis of C. vulgaris was not affected and that high levels of SPP may even promote chlorophyll synthesis. Superoxide dismutase and catalase activities of C. vulgaris increased during 24-120h exposure to SPP, but these activities gradually decreased as culture time progressed. In other words, the initial detrimental effects of synthetic SPP on C. vulgaris were temporary and reversible. This research provides a scientific basis for applications of SPP in the environment.
五水硼酸钠（SPP）是一种稀有矿物。在本研究中，通过低温结晶法由硼酸和硼砂合成了SPP，并评估了其对普通小球藻（C. vulgaris）生长的影响。通过化学分析、X射线衍射、傅里叶变换红外光谱、拉曼光谱、热重分析和差示热分析对新合成的SPP进行了表征。评估了普通小球藻在暴露于SPP 168小时后的生长、叶绿素含量和酶活性的变化。结果表明，在暴露的前24 - 120小时内，SPP处理对普通小球藻的生长有害。然而，即使在有效介质浓度为226.37mg BL(-1)（每升培养基中硼的施用浓度）的情况下，随着时间的推移（168小时），有害影响也会减弱。叶绿素含量（叶绿素a和b）也观察到类似趋势，表明普通小球藻的光合作用未受影响，甚至高浓度的SPP可能会促进叶绿素合成。在暴露于SPP的24 - 120小时内，普通小球藻的超氧化物歧化酶和过氧化氢酶活性增加，但随着培养时间的延长，这些活性逐渐降低。换句话说，合成SPP对普通小球藻的初始有害影响是暂时的且可逆的。本研究为SPP在环境中的应用提供了科学依据。
