Pseudomonas putida胞外聚合物吸附重金属镍的空间差异性及其作用机理  

Spatial differences and mechanism of Ni(Ⅱ) adsorption by extracellular polymers of Pseudomonas putida

作　　者：殷柏轩 孙水裕[1,3] 黄宇 廖小健 刘敬勇 卢明敏[4] 曾刘婷 李寿朋 YIN Baixuan;SUN Shuiyu;HUANG Yu;LIAO Xiaojian;LIU Jingyong;LU Mingmin;ZENG Liuting;LI Shoupeng(School of Environmental Science and Engineering,Guangdong University of Technology,Guangzhou 510006;Analysis and Test Center,Guangdong University of Technology,Guangzhou 510006;Guangdong Polytechnic of Environmental Protection Engineering,Foshan 528216;Guoke(Foshan)Testing and Certification Co.,Ltd.,Foshan 528000)

机构地区：[1]广东工业大学环境科学与工程学院,广州510006 [2]广东工业大学分析测试中心,广州510006 [3]广东环境保护工程职业学院,佛山528216 [4]国科(佛山)检测认证有限公司,佛山528000

出　　处：《环境科学学报》2024年第5期25-36,共12页Acta Scientiae Circumstantiae

摘　　要：结合态的胞外聚合物(Bound Extracellular Polymeric Substances,B-EPS)在处理重金属污染方面表现出较大的潜力,其在微生物细胞膜上呈动态双层结构:外层松散结合层EPS(Loosely Bound EPS,LB-EPS)和内层紧密结合层EPS(Tightly Bound EPS,TB-EPS),内外层EPS成分的空间分布及其对废水中重金属的消减规律目前尚不明确.本研究以恶臭假单胞菌(Pseudomonas putida,P.putida)为研究对象,探究目标重金属Ni(Ⅱ)胁迫前后P.putida产生的B-EPS的内外层EPS的物质组成与吸附性能的差异.胁迫试验结果表明,P.putida在10 mg·L^(-1) Ni(Ⅱ)胁迫下,B-EPS产量最高,TB-EPS蛋白质含量增加19.87%,LB-EPS蛋白质含量减少14.96%,多糖和核酸组分无明显变化.Ni(Ⅱ)吸附试验结果表明,B-EPS、TB-EPS、LB-EPS均能在30 min达到吸附平衡,TB-EPS在B-EPS吸附Ni(Ⅱ)过程中起到主要作用.内外层EPS在吸附Ni(Ⅱ)时在空间差异性,TB-EPS与LB-EPS中蛋白质含量与Ni(Ⅱ)吸附容量具有正相关性.3D-EEM和FTIR机理实验结果表明,内外层EPS蛋白质含量的不同是产生吸附空间差异性的主要原因.Ni(Ⅱ)胁迫可以提高TB-EPS中酪氨酸/色氨酸类氨基酸和蛋白质的含量,并使其中的C=O、–COO–、C–N、C–OH等官能团含量增加,提高EPS与Ni(Ⅱ)络合能力.本研究可为提取EPS处理含重金属废水提供理论指导.Bound extracellular polymeric substances(B-EPS) exhibit substantial potential in the treatment of heavy metal pollution.They manifest as a dynamic bilayer structure on microbial cell membranes,comprising an outer loosely bound EPS(LB-EPS) layer and an inner tightly bound EPS(TBEPS) layer.The spatial distribution of these EPS components and their role in reducing heavy metals in wastewater remain unclear.This study,focused on Pseudomonas putida(P.putida),explores the differences in material composition and adsorption properties of inner and outer layer EPS produced by P.putida before and after exposure to the target heavy metal Ni(Ⅱ).Results from the stress tests indicate that under 10 mg·L^(-1) Ni(Ⅱ) stress,P.putida exhibited the highest B-EPS production.The TB-EPS protein content increased by 19.87%,while the LB-EPS protein content decreased by 14.96%,with no significant change in polysaccharide and nucleic acid components.Ni(Ⅱ) adsorption tests revealed that both B-EPS,TB-EPS,and LB-EPS reached adsorption equilibrium within 30 minutes,with TB-EPS playing a primary role in Ni(Ⅱ) adsorption during the process.There exists spatial differences in the adsorption of Ni(Ⅱ) between the inner and outer EPS layers,with a positive correlation between protein content and Ni(Ⅱ) adsorption capacity in TB-EPS and LB-EPS.Results from 3D-EEM and FTIR mechanism experiments indicate that differing protein content in the inner and outer EPS layers is the primary cause of the adsorption spatial differences.Ni(Ⅱ) stress can increase the content of tyrosine/tryptophan amino acids and proteins in TB-EPS and enhance the content of functional groups like C=O,–COO–,C–N,C–OH,thereby improving the complexation capability of EPS with Ni(Ⅱ).This study provides theoretical guidance for extracting EPS in the treatment of heavy metal-containing wastewater.

关 键 词：胞外聚合物 空间差异 重金属胁迫 恶臭假单胞菌 生物吸附 

分 类 号：X703[环境科学与工程—环境工程]