摘要
从细胞的生理代谢及微观形貌方面研究了1株酵母菌富集废水中铬的机理.阳离子运输实验表明:酵母菌在吸附铬的过程中,伴随着K+、Mg2+、Na+、Ca2+等阳离子的大量释放,铬离子和质子的跨膜运输与胞内阳离子释放相耦合;反应30 min,细胞对铬的吸附接近饱和,阳离子与铬的交换达到平衡.同时细胞分泌酰胺和蛋白等有机分子,作为Cr(Ⅵ)的还原性物质及离子主动运输的载体,促进了铬的胞内积累.原子力显微镜、扫描电镜、X射线衍射能谱分析吸附铬前后细胞微观形貌、元素含量变化:细胞表面高毒性铬的沉积、细胞膜通透性的增强、铬与细胞内有机大分子的螯合作用,及胞内大量维持细胞结构的阳离子向体外扩散等行为破坏了细胞的微观结构,致使细胞产生空壳、内陷甚至裂解等现象.
Physiology metabolism and micro morphology were studied to reveal mechanism of chromium accumulation in wastewater by yeast. Cation transportation experiment showed that the transportation of Cr, H ion coupled with release of intracellular K^＋、Mg^2＋、Na^＋、Ca^2＋ in the process of biosorption and in 30 rain the biosorption approached saturation and the exchange between Cr and cations reached balance. Meanwhile the cell secreted amide and protein which acted as reduction products of chromium （ Ⅵ ） and carriers of ion transportation to accelerate the intracellular accumulation of chromium. Atomic force microscopy （AFM）, scanning electron microscopy （SEM） and energydispersive X-ray spectra analysis celtificated that the microstructure of cells were destroyed and the retraction, empty and fission of cells appeared because of microprecipitation of chromium on cell surface, increasing permeability of cell membrane, chelation of Cr and organic high molecule in cells and release of cations from cells.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2007年第1期194-198,共5页
Environmental Science
基金
国家自然科学基金项目(50278040)
广东省科技厅科技计划重大专项(2004A30308002)
关键词
铬
酵母菌
离子运输
吸附机理
细胞形貌
chromium
yeast
ion transportation
biosorption mechanism
cell morphology
