摘要
Shewanella putrefaciens CN32模拟在非饱和环境中生长的生物膜,探究不同环境条件对非饱和生物膜胞内外大分子物质的影响,以及生物膜对重金属Cr的作用.在84 h、219 mmol·L^(−1) NaCl、pH 6.2和35℃条件下,生物膜分泌胞外聚合物的量达到最大,每片生物膜胞外聚合物总量为400.6μg;生长12 h的每片生物膜中胞外聚合物吸附了9.77μg Cr,占生物膜总吸附量的63.8%;三维荧光光谱表明,生物膜吸附Cr后胞外聚合物中色氨酸蛋白类物质与酪氨酸蛋白类物质荧光强度明显降低.结果表明,一定强度的渗透压、低pH和高温能促进生物膜分泌更多的胞外聚合物.非饱和生物膜中,胞外聚合物是重金属Cr的主要结合区域,并且胞外聚合物中的色氨酸蛋白类物质与酪氨酸蛋白类物质可能在与Cr络合中起重要作用.
Shewanella putrefaciens CN32 was selected to simulate the biofilm growing in unsaturated environment.The influence of different environmental factors on the extracellular and intracellular macromolecular substances of unsaturated biofilms,as well as the interactions between the unsaturated biofilms and heavy metal Cr were explored.Under the conditions of 84 h,219 mmol·L^(−1) NaCl,pH 6.2 and 35℃,the extracellular polymeric substances(EPS)secreted by biofilms reached the maximum content of 400.6μg per biofilm.The EPS in each biofilm grown for 12 h adsorbed 9.77μg Cr,accounting for 63.8%of the total amount of the adsorbed Cr.Threedimensional fluorescence spectroscopy shows that the fluorescence intensities of tryptophan and tyrosine proteins in the EPS was significantly reduced after Cr adsorption.In addition,a certain strength of osmotic pressure,low pH and high temperature could promote the EPS secretion by the biofilms.The EPS in the unsaturated biofilms were the main binding area of Cr,and the tryptophan and tyrosine proteins were suggested to play an important role in the complexation between biofilms and Cr.
作者
安辉
王梓婷
金若菲
周集体
AN Hui;WANG Ziting;JIN Ruofei;ZHOU Jiti(School of Environment Science and Technology,Dalian University of Technology,Key Laboratory of Industrial Ecology and Environmental Engineering,MOE,Dalian,116024,China)
出处
《环境化学》
CAS
CSCD
北大核心
2022年第6期1880-1889,共10页
Environmental Chemistry
基金
大连市重点科技研发计划项目(2018YF24SN073)资助.
关键词
非饱和生物膜
CR
胞外聚合物
络合
unsaturated biofilms
Cr
extracellular polymeric substances
complexation
