Khan Razia, Fulekar M H
School of Environment and Sustainable Development, Central University of Gujarat, Gandhinagar, Gujarat 382030 India.
Bioresour Bioprocess. 2017;4(1):23. doi: 10.1186/s40643-017-0153-9. Epub 2017 May 17.
Reactive Red 31, applied extensively in the commercial textile industry, is a hazardous and persistent azo dye compound often present in dye manufacturing and textile industrial effluents. strain was isolated from dye contaminated zones of Gujarat Industrial Development Corporation, Vatva, Ahmedabad, India. The decolorization potential was monitored by the decrease in maximum absorption of the dye using UV-visible spectroscopy. Optimization of physicochemical conditions was carried out to achieve maximum decolorization of Reactive Red 31 by fungal pellets.
Pellets of strain were found to decolorize this dye (20 mg/L) under aerobic conditions within 12 h. The activity of azoreductase, laccase, phenol oxidase and Manganese peroxidase in fungal culture after decolorization was about 8, 7.5, 19 and 23.7 fold more than before decolorization suggesting that these enzymes might be induced by the addition of Reactive Red 31 dye, and thus results in a higher decolorization. The lab-scale reactor was developed and mineralization of Reactive Red 31 dye by fungal pellets was studied at 6, 12 and 24 h of HRT (hydraulic retention time). At 12 h of HRT, decolorization potential, chemical oxygen demand (COD) and total organic carbon reduction (TOC) was 99.02, 94.19, and 83.97%, respectively, for 20 mg/L of dye concentration.
Dye decolorization potential of culture was influenced by several factors such as initial dye concentration, biomass concentration, pH, temperature, and required aerated conditions. Induction of azoreductase, laccase, phenol oxidase, and Mn-peroxidase enzymes was observed during dye decolorization phase. pellets showed potential in mineralization of dye in the aerobic reactor system. Isolated fungal strain showed better dye decolorization performance in short duration of time (12 h) as compared to other reported fungal cultures.Graphical abstractDegradation of RR31 dye in developed aerobic fungal pelleted reactor.
活性红31广泛应用于商业纺织工业，是一种危险且持久的偶氮染料化合物，常存在于染料制造和纺织工业废水中。该菌株是从印度艾哈迈达巴德瓦德瓦古吉拉特工业发展公司的染料污染区分离得到的。通过紫外可见光谱法测定染料最大吸收值的降低来监测脱色潜力。对理化条件进行了优化，以实现真菌菌球对活性红31的最大脱色。
发现该菌株的菌球在有氧条件下12小时内可使这种染料（20mg/L）脱色。脱色后真菌培养物中偶氮还原酶、漆酶、酚氧化酶和锰过氧化物酶的活性分别比脱色前高约8、7.5、19和23.7倍，这表明这些酶可能是由活性红31染料的添加诱导产生的，从而导致更高的脱色率。开发了实验室规模的反应器，并研究了在水力停留时间（HRT）为6、12和24小时时真菌菌球对活性红31染料的矿化作用。对于20mg/L的染料浓度，在HRT为12小时时，脱色潜力、化学需氧量（COD）和总有机碳减少量（TOC）分别为99.02%、94.19%和83.97%。
该菌株的染料脱色潜力受初始染料浓度、生物量浓度、pH值、温度和所需曝气条件等多种因素影响。在染料脱色阶段观察到偶氮还原酶、漆酶、酚氧化酶和锰过氧化物酶的诱导作用。该菌株的菌球在好氧反应器系统中显示出染料矿化的潜力。与其他报道的真菌培养物相比，分离得到的真菌菌株在短时间（12小时）内表现出更好的染料脱色性能。
在开发的好氧真菌菌球反应器中RR31染料的降解。
