Optimization of conditions for decolorization of azo-based textile dyes by multiple fungal species
Optimization of conditions for decolorization of azo-based textile dyes by multiple fungal species
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DOI：
10.1016/j.jbiotec.2017.08.022
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发表时间：
2017-10-20
影响因子：
4.1
通讯作者：
Sadowsky, Michael J.
中科院分区：
文献类型：
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作者：
El-Rahim, Wafaa M. Abd;Moawad, Hassan;Sadowsky, Michael J.
来自纺织工业的废水含有偶氮染料残留物，对大多数环境系统产生负面影响。出于安全和成本考虑，生物处理这些废物是最佳选择。本研究对19株偶氮染料降解真菌进行了分离鉴定，并优化了降解条件。真菌属于五种曲霉和一个单一的Lichtheimia sp.所有真菌进行了评价，他们的能力，20偶氮染料的脱色。最易转化的偶氮染料是直接紫（脱色率为71.1%~ 93.3%），最难脱色的是耐晒绿色偶氮染料。最大的降解潜力的偶氮染料（直接紫和甲基红）进行了优化，使用最有前途的四种真菌菌株和改变培养基中的葡萄糖浓度，氮源，和微量营养素。生物量，木质素过氧化物酶和漆酶的生产也确定在优化研究。添加葡萄糖后，四株真菌对两种偶氮染料的脱色率均显著提高。在缺乏有机氮源的情况下，真菌菌株不能产生木质素过氧化物酶。酵母提取物和酪蛋白氨基酸的补充增强脱色的直接紫和甲基红染料和生产的木质素过氧化物酶的真菌菌株。相反，漆酶在富含相同有机氮源的类似培养基中不存在。
Wastewater from textile industries contains azo dye residues that negatively affect most environmental systems. The biological treatment of these wastes is the best option due to safety and cost concerns. Here we isolated and identified 19 azo dye-degrading fungi and optimized conditions resulting in enhanced degradation. The fungi belonged to five species of Aspergillus and a single Lichtheimia sp. All fungi were evaluated for their ability to decolorize 20 azo dyes. While the most easily transformable azo dye was direct violet (decolorization ranged from 71.1 to 93.3%), the most resistant to decolorization was fast green azo dye. The greatest degradation potential of azo dyes (direct violet and methyl red) was optimized using the most promising four fungal strains and changing media glucose concentration, nitrogen source, and micronutrients. Biomass, lignin peroxidase, and laccases production were also determined in the optimization studies. The decolorization of both azo dyes by the four fungal strains was greatly enhanced by glucose supplementation. The fungal strains were not able to produce lignin peroxidases in the absence of organic nitrogen source. Both yeast extract and casamino acid supplementation enhanced decolorization of direct violet and methyl red dyes and production of lignin peroxidase by the fungal strains. In contrast, the laccases were absent in the similar medium enriched with the same organic nitrogen sources.