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作者： Xue Qiang Zhao1, Xue Min Bao1,3, Chao Wang1, Zuo Yi Xiao3, Zhen Min Hu1,4, Chun Li Zheng1,2, Ren Fang Shen1,
1.State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil ScienceChinese Academy of SciencesNanjingChina
2.School of Life Science and TechnologyInner Mongolia University of Science and TechnologyBaotouChina
3.School of Environment and EnergyInner Mongolia University of Science and TechnologyBaotouChina
4.University of Chinese Academy of SciencesBeijingChina
摘要：Aluminum (Al) is ubiquitous and toxic to microbes. High Al3+ concentration and low pH are two key factors responsible for Al toxicity, but our present results contradict this idea. Here, an Al-tolerant yeast strain Rhodotorula taiwanensis RS1 was incubated in glucose media containing Al with a continuous pH gradient from pH 3.1–4.2. The cells became more sensitive to Al and accumulated more Al when pH increased. Calculations using an electrostatic model Speciation Gouy Chapman Stern indicated that, the increased Al sensitivity of cells was associated with AlOH2+ and Al(OH)2+ rather than Al3+. The alcian blue (a positively charged dye) adsorption and zeta potential determination of cell surface indicated that, higher pH than 3.1 increased the negative charge and Al adsorption at the cell surface. Taken together, the enhanced sensitivity of R. taiwanensis RS1 to Al from pH 3.1–4.2 was associated with increased hydroxy-Al and cell-surface negativity.
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