陈丽杰，王志存，葛旭萌，白凤武

大连理工大学生命科学与技术学院，大连 116024

絮凝酵母吸附Cr(VI) 的机理

陈丽杰，王志存，葛旭萌，白凤武

大连理工大学生命科学与技术学院，大连 116024

絮凝酵母SPSC01为酿酒酵母Saccharomyces cerevisiae和粟酒裂殖酵母Schizosaccharomyces pombe的融合菌株，用其吸附水溶液中的重金属 Cr(VI)，可以大大降低生物吸附的固液分离成本。为了探讨 SPSC01菌体絮凝蛋白对Cr(VI) 还原吸附的影响，对SPSC01与其亲本菌株的吸附行为进行了比较。结果表明，SPSC01和其具有絮凝性状的亲本S. pombe的Cr(VI) 去除速率基本同步，远优于无絮凝性状的亲本S. cerevisiae；达到吸附平衡时，S. pombe、SPSC01和S. cerevisiae对总Cr去除率分别达68.8%、48.6%和37.5%；从而证明了絮凝有利于Cr(VI) 的还原、吸附，絮凝蛋白在Cr(VI) 的还原吸附过程中起促进作用。通过化学屏蔽方法和傅立叶变换红外光谱 (FTIR) 分析，对SPSC01菌体表面吸附Cr(VI) 的机理进行了研究，结果表明SPSC01菌体表面吸附Cr(VI) 起主要作用的基团是氨基、羧基和酰胺基。

絮凝酵母，生物吸附，Cr(VI)，吸附机理

Abstract:The flocculating yeast strain SPSC01 is a fusant strain of Saccharomyces cerevisiae and Schizosaccharomyces pombe.The use of SPSC01 to absorb Cr(VI) from Cr(VI) containing aqueous solution would greatly reduce the cost of post-adsorption separation, since the superior flocculating property of SPSC01 would allow easy separation of the Cr(VI)-biomass from the solution. In order to investigate the effects of flocculating proteins on Cr(VI) reduction and absorption by SPSC01, the absorption behaviors of SPSC01 and its parental strains were compared. The results showed that Cr(VI) removal rate of SPSC01 was almost the same as that of S. pombe, which also has flocculating ability, but was faster than that of S. cerevisiae, which has no flocculating ability. When the system reached equilibrium, the amount of total Cr adsorbed by S. pombe, SPSC01 and S. cerevisiae were 68.8%,48.6% and 37.5%, respectively. This showed that flocculation was beneficial to Cr(VI) reduction and adsorption, and suggested that focculating proteins may play a role in enhancing the Cr(VI) adsorption capacity of SPSC01 and S. pombe. We investigated the mechanism of Cr(VI) adsorption by SPSC01 using chemical modification and FTIR. The results indicated that the major functional groups (amino, carboxyl and amide) of surface proteins may contribute to the absorption of Cr(VI).

Keywords:flocculating yeasts, biosorption, Cr(VI), mechanisms of adsorption

重金属污染是当今世界严重的环境问题之一[1]。Cr是一种典型的重金属污染物。处理重金属污染的传统方法包括：化学沉淀、离子交换、活性炭吸附等。它们的缺点在于处理费用高，并且在低浓度时(＜100 mg/L) 处理效率低[2]。重金属生物吸附法可以克服传统处理方法的弊端[3-4]，并且生物吸附剂来源广泛、成本低廉。但是由于生物吸附剂尺度小、密度低、固液分离困难致使其在重金属废水处理领域的应用受到限制，因此生物吸附剂的固定化技术和相关的研究受到极大关注，目前已有大量的研究成果发表[5-10]。……