Abstract
In this study, the Metanil Yellow (MY) decolorizing mixed culture, namely FN3, has been isolated from agriculture soil. The mixed culture was immobilized using gellan gum. In order to optimize the immobilization process for maximal dye decolorization, Response Surface Methodology (RSM) was performed. The optimal conditions for immobilization predicted by desirability function are 130 mg/L of MY dye concentration, 1.478% of gellan gum concentration, 50 beads and 0.6 cm of beads size with the percentage of decolorization of 90.378%. The correlation coefficients of the model (R2 and R2 adj) are 0.9767 and 0.9533, respectively. This indicates that the established model is suitable to predict the effectiveness of dye decolorization under the investigated condition. The immobilized beads of mixed culture FN3 were able to be reused up to 15 batches of decolorization. The immobilized cells also have high tolerance towards heavy metals. This was proven by higher dye decolorization rate by the immobilized cells even with the addition of heavy metals in the media. The decolorization potential of the mixed culture indicates that it could be useful for future bioremediation of soil contaminated sites and treatment solutions of water bodies polluted with MY dye.
Highlights
Azo dyes are extensively used in various industries such as textile industry, food, paper-making and cosmetic industries [1,2]
The mixed culture FN3 was grown on a large scale in minimal salt medium (MSM) supplemented with 50 mg/L of Metanil Yellow (MY) dye
This study focused on the combined effects of four significant variables for the decolorization of MY dye by mixed culture FN3
Summary
Azo dyes are extensively used in various industries such as textile industry, food, paper-making and cosmetic industries [1,2]. Researchers are finding various ways of removing dyes from wastewater As they are relatively resistant to biodegradation, the elimination of coloured effluents in wastewater treatment systems is mainly based on physical or chemical procedures such as adsorption, concentration, chemical transformation and incineration [11]. These methods are high-energy costs, high sludge production and formation of byproducts [12]. Degradation and decolorization of azo dye by bacteria proceeds in two stages. According to the previous study, it has been reported that mixed bacterial culture can give a better degradation rate than the individual strain. To the best of our knowledge, no study has reported on the immobilization of mixed culture using gellan gum to decolorize MY dye. Many works reported on the use of pure culture of bacteria instead of the mixed culture of bacteria, as reported in this study
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
