Jadhav J P, Govindwar S P
Department of Biochemistry, Shivaji University, Kolhapur 416 004, India.
Yeast. 2006 Mar;23(4):315-23. doi: 10.1002/yea.1356.
In recent years, use of microbial biomass for decolourization of textile industry wastewater is becoming a promising alternative in which some bacteria and fungi are used to replace present treatment processes. Saccharomyces cerevisiae MTCC 463 decolourized the triphenylmethane dyes (malachite green, cotton blue, methyl violet and crystal violet) by biosorption, showing different decolourization patterns. However, malachite green decolourized by biosorption at the initial stage and further biodegradation occurred, about 85% in plain distilled water within 7 h, and about 95.5% in 5% glucose medium within 4 h, under aerobic conditions and at room temperature. Decolourization of malachite green depends on various conditions, such as concentration of dye, concentration of cells, composition of medium and agitation. HPLC, UV-VIS, FTIR and TLC analysis of samples extracted with ethyl acetate from decolourized culture flasks confirmed the biodegradation of malachite green into several metabolites. A study of the enzymes responsible for the biodegradation of malachite green in the control and cells obtained after decolourization showed the activities of laccase, lignin peroxidase, NADH-DCIP reductase, malachite green reductase and aminopyrine N-demethylase in control cells. A significant increase in the activities of NADH-DCIP reductase and MG reductase was observed in the cells obtained after decolourization, indicating a major involvement of reductases in malachite green degradation.
近年来，利用微生物生物质对纺织工业废水进行脱色正成为一种有前景的替代方法，其中一些细菌和真菌被用于取代现有的处理工艺。酿酒酵母MTCC 463通过生物吸附作用使三苯甲烷染料（孔雀石绿、棉蓝、甲基紫和结晶紫）脱色，呈现出不同的脱色模式。然而，孔雀石绿在初始阶段通过生物吸附脱色，随后发生进一步的生物降解，在有氧条件和室温下，在纯蒸馏水中7小时内脱色约85%，在5%葡萄糖培养基中4小时内脱色约95.5%。孔雀石绿的脱色取决于多种条件，如染料浓度、细胞浓度、培养基组成和搅拌情况。用乙酸乙酯从脱色培养瓶中提取的样品进行的高效液相色谱（HPLC）、紫外可见光谱（UV-VIS）、傅里叶变换红外光谱（FTIR）和薄层色谱（TLC）分析证实了孔雀石绿被生物降解为几种代谢产物。对对照组和脱色后获得的细胞中负责孔雀石绿生物降解的酶的研究表明，对照组细胞中有漆酶、木质素过氧化物酶、NADH-DCIP还原酶、孔雀石绿还原酶和氨基比林N-脱甲基酶的活性。在脱色后获得的细胞中观察到NADH-DCIP还原酶和MG还原酶的活性显著增加，表明还原酶在孔雀石绿降解中起主要作用。
