摘要
通过液体培养及吸附试验,研究了Cd^(2+)胁迫下蜡样芽胞杆菌生长及其胞外聚合物(EPS)的产生规律、产量和组成,以及菌体和EPS对Cd^(2+)的吸附作用。结果表明,蜡样芽胞杆菌在不同Cd^(2+)浓度胁迫下均可生长,随着Cd^(2+)浓度的增加,各生长时期均有所延后,EPS的生成量与菌体生长曲线具有一定耦合关系,EPS最大生成量为1.707 g/L,多糖与蛋白质含量之和占EPS干质量的68%~87%。对Cd^(2+)的吸附能力大小顺序为细菌菌体-EPS复合物>EPS>细菌菌体(不含EPS)。透射电镜-X射线光散射能谱(SEM-EDX)分析结果显示,吸附Cd^(2+)后蜡样芽胞杆菌细胞形态及表面结构发生改变,细胞表面形成Cd^(2+)吸收峰,EPS吸附Cd^(2+)后表面形成不规则的含有Cd^(2+)的颗粒状物质。
In this research,the adsorption of Cd2+by Bacillus cereus and its extracellular polymeric substances(EPS)was studied.The growth of Bacillus cereus and the production rules,yield and composition of its EPS under Cd2+stress were also investigated through the liquid culture and adsorption experiment.The results showed that Bacillus cereus could grow under different Cd2+concentrations stress.As the Cd2+concentration increased,each growth period had been delayed,and the EPS yield had a certain coupling relationship with growth cur^^e of the Bacillus cereus.The maximum yield of EPS was1.707g/L.The sugar and protein content accounted for68to87percent of the dry weight of EPS.The order based on Cd2+adsorption capacity was as follows:Bacillus cereus>EPS>Bacillus cereus(excluding EPS).The results of SEM-EDX analysis showed that the cell morphology and surface structure of Bacillus cereus had changed after adsorption of Cd2+.The cell surface formed Cd2+absorption peak after adsorption of Cd2+.EPS surface formed irregular granular material containing Cd2+after adsorption.
作者
李学龙
刘国丽
李超
李跃
杨镇
LI Xue-long;LIU Guo-li;LI Chao;LI Yue;YANG Zhen(Institute of Edible Fungi/Research Center of Microbial Engineering ,Liaoning Academy of Agricultural Sciences, Shenyang 110161,China)
出处
《江苏农业学报》
CSCD
北大核心
2018年第2期327-332,共6页
Jiangsu Journal of Agricultural Sciences
基金
沈阳市重点科技研发计划项目(17-163-3-00)
关键词
蜡样芽孢杆菌
胞外聚合物
Cd2+
生物吸附
Bacillus cereus
extracellular polymeric substances(EPS)
Cd2+
biosorption
