嗜热菌群降解偶氮染料的特性及机制  

Decolorization characteristics and mechanism of azo dyes by a thermophilic bacterial consortium

作　　者：毕欣妍 曹珂欣 黄晓倩 庄毅 郭光 田芳 丁克强 杨凤 刘翀[2] BI Xinyan;CAO Kexin;HUANG Xiaoqian;ZHUANG Yi;GUO Guang;TIAN Fang;DING Keqiang;YANG Feng;LIU Chong(School of Environmental Engineering,Nanjing Institute of Technology,Nanjing 211167,Jiangsu,China;Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081,China)

机构地区：[1]南京工程学院环境工程学院,江苏南京211167 [2]中国农业科学院农业环境与可持续发展研究所,北京100081

出　　处：《微生物学通报》2023年第4期1464-1480,共17页Microbiology China

基　　金：国家自然科学基金(31600091);南京工程学院创新基金(CKJB202207);江苏省高等学校大学生实践创新训练计划(202211276070Y,202211276071Y)。

摘　　要：【背景】印染废水的出水温度高,抑制了微生物对偶氮染料的降解,而关于嗜热菌在高温下降解偶氮染料的报道较少。【目的】富集能在高温下降解偶氮染料的嗜热微生物菌群,并研究其降解潜力和基因组特征。【方法】通过富集的方法获得嗜热微生物菌群,利用分光光度法测定其降解特性;采用全波长扫描、傅里叶变换红外吸收光谱(Fourier transform infrared spectroscopy,FTIR)和气相质谱(gas chromatography-mass spectrometer,GC-MS)分析其降解机理;采用植物毒性的方法比较偶氮染料降解前后的毒性;采用高通量测序技术分析其功能基因和群落结构。【结果】该菌群(SD1)可以在65℃降解偶氮染料,Caldibacillus、unclassified_f__Bacillaceae、Geobacillus等为优势属,在降解过程中起关键作用;菌群SD1能在较宽泛的pH(5.0−9.0)、温度(50−75℃)、染料浓度(100−500 mg/L)和盐度(1%−5%)降解酸性大红GR;偶氮还原酶和NADH-DCIP是主要的降解酶,GC-MS和FTIR结果表明菌群SD1通过偶氮键断裂降解酸性大红GR;植物毒性的结果表明,经菌群SD1脱色后酸性大红GR的毒性降低;与降解有关的功能基因有依赖NADH的黄素单核苷酸(flavin mononucleotide,FMN)偶氮还原酶基因和依赖FMN的还原酶基因。【结论】嗜热菌群SD1在处理高温印染废水中具有很大的应用潜力。[Background]The high temperature of textile wastewater inhibits the degradation of azo dyes by microorganisms.Little is known about the degradation of azo dyes by thermophiles.[Objective]To enrich the thermophilic microbiota that can degrade azo dyes at high temperature and study their degradation potential and genomic characteristics.[Methods]We obtained a thermophilic bacterial consortium by the enrichment method and then studied its degradation characteristics by spectrophotometry.The degradation mechanism was analyzed by full-wavelength scanning,Fourier transform infrared spectroscopy(FTIR),and gas chromatography-mass spectrometry(GC-MS).The phytotoxicity of azo dyes before and after degradation was compared.The functional genes and structure were analyzed by high-throughput sequencing.[Results]A bacterial consortium(SD1)was enriched,which can degrade azo dye at 65℃.SD1 was mainly composed of Caldibacillus,unclassified_f__Bacillaceae,and Geobacillus.It could degrade acid red GR within pH 5.0–9.0,50–75℃,dye concentration of 100–500 mg/L,and salinity of 1%–5%.Azo reductase and NADH-DCIP were the main degrading enzymes.The results of GC-MS and FTIR demonstrated that the azo bond was broken by SD1.The phytotoxicity of acid red GR decreased after degradation.The genes encoding NADH-dependent flavin mononucleotide(FMN)azo reductase and FMN-dependent reductase involved in the degradation were detected.[Conclusion]The thermophilic bacterial consortium SD1 has great potential to be applied in the treatment of high-temperature textile wastewater.

关 键 词：偶氮染料 嗜热菌 脱色 酸性大红GR 宏基因组 

分 类 号：X791[环境科学与工程—环境工程] X172