Microorganisms For The Degradation Of Toxic Chemical Textile Essay


Discuss about the Microorganisms For The Degradation Of Toxic Chemical Textile.



This study highlights the use of microorganisms for the degradation of toxic chemical textile dyes such as Mordant Black 17 (Calcon) that is present in the effluents of the textile industries (Sunkar & Renugadevi, 2015). The paper illustrates the isolation of the dye degrading bacteria from the site contaminated by the textile effluents. These are further characterized using biochemical and molecular methods like 16s RNA sequencing method. Additionally the paper analyses the decolourization activity of the microorganisms along with the characterization of the metabolites that are produced after the decolourisation using several analytical methods such as TLC analysis, FTIR analysis and GC–MS analysis.


Treatment and reuse of industrial effluents is quite necessary for the provision of clean water supply. With the increasing amount of application of chemical dyes in the textile industries, which are toxic in nature, there is an immediate need to find ways for the degradation of these chemical textile dyes (Chequer et al, 2013). These dyes are classified into acidic, basic, disperse, azo, diazo, anthraquinone and metal complex based on their structure. Based on the dyeing process, textile dyes are classified as reactive, direct, disperse, acid, basic and vat dyes (Gupta et al., 2015). Earlier many traditional methods have been followed like chemical degradation but with the increase on the focus of green technology, the method of biodegradation is being implemented for the removal of the chemical dyes form the effluents of the textile industries (Khan, Bhawana & Fulekar, 2013). Here the focus is on the use of microorganisms for the degradation since this method is cost-effective as well as an environmental friendly approach.

Proposal plan

The study proposes that dye degrading microorganisms will be isolated from the sites that are contaminated by chemical effluents from the textile industries. The organisms collected will be further sampled using serial dilution and pour plated in nutrient agar plates. After an incubation period of 24 hours, the colonies will be picked from these plates depending on the proper colour, texture, and other morphological characteristics. This will be inoculated separately in order to maintain a pure culture. For further use, glycerol stock solution of the pure culture will be maintained at -20 C. For the 16s RNA sequencing of the culture, PCR amplification followed by DNA sequencing will be one in order to isolate the genomic DNA of the pure culture. The PCR product was sequenced bi-directionally using the forward, reverse and internal primer. To identify the bacterium, the sequence data was aligned and analysed to its closest neighbours (Karunya, Rose & Nachiyar, 2014).

To provide optimum growth conditions, the culture medium will be optimized using a variety of mineral salts in varying compositions. An important factor is pH. Optimum pH conditions needs to be provided for promoting effective growth of the organism. The carbon source will also be varied such as glucose, which may be replaced by other sources such as lactose, sucrose, fructose, maltose and dextrose, while optimising the culture medium. In order to carry out the decolourization experiment, a stock solution of the dye will be needed to be made of a particular concentration (Selvakumar, Manivasagan & Chinnappan, 2013).

The degradation experiments will be conducted by adding the culture in specific amounts such as 100 mg l-1 into the culture medium and will be incubated overnight at 32 C at 150 rpm. Butanol extraction method will be carried out next for determination of the degradation. The amount of decolourisation of the dye due to degradation will be measured by the change in absorbance of culture supernatants at the maximum absorption wavelength (?max) of 520 nm using a spectrophotometer. The rate of decolourization can will be calculated by considering the difference between the initial and the final absorption values of the supernatant at ?max of the dye. This can be followed by a protein content and analysis and the glucose utilization analysis with the help of Lowry method and DNS method respectively. A triplicate set of experiments will be conducted in each case (Karunya, Rose & Nachiyar, 2014).

After the degradation assay, experiments will be conducted in order to identify the metabolites that are formed after degradation. Characterizations include the TLC analysis, FTIR analysis and GC–MS analysis. Thin layer chromatography (TLC) analysis for the breakdown products will performed on fluorescent silica plates. Identification of naphthoquinone is done by using the solvent system of isopropanol: acetic acid: water in the ratio of 19:9:1. The compound will be identified by comparing the Rf values with that of standard. Fourier Transform Infra-Red (FTIR) spectroscopic analysis of the spot from TLC plate, (eluted using ethyl acetate) was carried out in a FTIR spectrophotometer. Centrifugation will be carried out of the culture medium containing the degradation products after the incubation period and the supernatant will be extracted thrice with equal volume of ethyl acetate, dried over anhydrous Na2SO4. Next the solvent will be made to evaporate in a rotary evaporator. Gas chromatography–mass spectroscopy (GC–MS) analysis of the ethyl acetate extract will be performed by using GC–MS spectrometer. The column used was VF-5 ms, 30 m ? 0.250 mm diameter with the film thickness of 0.25 m and the column oven was programmed between 70 and 300 ?C at the rate of 10 ?C per minute with the injection temperature of 240 ?C. Mass spectra were recorded under scan mode in the range of 40–1000 m/z. Compounds were identified using WILEY8.LIB (Sunkar & Renugadevi, 2015).



Budget in Canadian dollar (CAD)

Isolation and characterization of the microorganism


Optimization of the culture medium


Decolourisation assay


Identification of the metabolites






Time required

Isolation and characterization of the microorganism

2-3 months

Optimization of the culture medium

1 month

Decolourisation assay

2-3 weeks

Identification of the metabolites

1 – 2 months


Chequer, F. M. D., de Oliveira, G. A. R., Ferraz, E. R. A., Cardoso, J. C., Zanoni, M. V. B., & de Oliveira, D. P. (2013). Textile dyes: dyeing process and environmental impact. In Eco-friendly textile dyeing and finishing. InTech.

Gupta, V. K., Khamparia, S., Tyagi, I., Jaspal, D., & Malviya, A. (2015). Decolorization of mixture of dyes: a critical review. Global Journal of Environmental Science and Management, 1(1), 71-94.

Hassan, M. M., Alam, M. Z., & Anwar, M. N. (2013). Biodegradation of textile azo dyes by bacteria isolated from dyeing industry effluent. Int Res J Biol Sci, 2(8), 27-31.

Karunya, A., Rose, C., & Nachiyar, C. V. (2014). Biodegradation of the textile dye Mordant Black 17 (Calcon) by Moraxella osloensis isolated from textile effluent-contaminated site. World Journal of Microbiology and Biotechnology, 30(3), 915-924.

Khan, R., Bhawana, P., & Fulekar, M. H. (2013). Microbial decolorization and degradation of synthetic dyes: a review. Reviews in Environmental Science and Bio/Technology, 12(1), 75-97.

Selvakumar, S., Manivasagan, R., & Chinnappan, K. (2013). Biodegradation and decolourization of textile dye wastewater using Ganoderma lucidum. 3 Biotech, 3(1), 71-79.

Sriram, N., Reetha, D., & Saranraj, P. (2013). Biological degradation of Reactive dyes by using bacteria isolated from dye effluent contaminated soil. Middle–East Journal of Scientific Research, 17(12), 1695-1700.

Sunkar, S., & Renugadevi, K. (2015). Citrobacter freundii mediated degradation of textile dye Mordant Black 17. Journal of Water Process Engineering, 8, 28-34.

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