Aerobic decolorization and degradation of azo dyes by a salt-tolerant yeast Cyberlindnera samutpraka

• 作 者: 宋莉 邵一钒 牟广迪 谭靓
• 机 构: 辽宁省大连市甘井子区柳树南街1号,辽宁师范大学生命科学学院
• 出 处: 第二十次全国环境微生物学学术研讨会
• 发表日期: 2017年10期
• 关键词: Azo dye Cyberlindnera samutprakarnensis Salt-tolerant Degradation pathway Enzyme

　　A salt-tolerant yeast named S4 which could decolorize various azo dyes was recently isolated and identified as Cyberlindnera samutprakarnensis.Systematic researches on characterization,degradation pathway and enzymes analysis of this salttolerant yeast were done.The results showed that the optimal metabolism and growth parameters for the yeast S4 were: 4.0 g L-1 sucrose,0.6 g L-1 ammonium sulfate,0.08 g L-1 yeast extract,30 g L-1NaCl,120 r min-1,30 ℃ and pH 6.0.More than 97% of 50 mg L-1 Acid Red B (ARB) could be decolorized within 18 h under the optimal conditions.The yeast S4 decolorized ARB through a possible pathway successively consisting ofazo-reduction,(hydroxylation) deamination,desulfonation and TCA cycle processes.Meanwhile,NADH-DCIP reductase was estimated intracellularly and extracellularly as the key reductase for decolorization.Ligninases including lignin peroxidase (LiP),manganese peroxidase (MnP) and laccase (Lac) were determined as important intracellular oxidoreductases for further degradation of decolorization intermediates.Furthermore,activities ofNADH-DCIP reductase,LiP and MnP were all inhibited by higher salinity.In comparison,activity of Lac was not influenced by the shift of salinity.