Presented by :- Shweta Agrawal Screening of Acid Black 210 Decolorizing Bacteria and Decolorization Study Presented by :- Shweta Agrawal

Introduction to Dye A dye is a colored substance that has an affinity to the substrate to which it is being applied. The name of ‘acid dyes’ refers to the dyeing process, which means these dyes are applied for dyeing nitrogen-containing fibers such as wool, silk and polyamides using from neutral to acidic solutions (pH 2-6). Most synthetic food colours falls in this category.

Hazard of Dyes During the synthesis of azo dyes and dyeing process in industries, dyes that are lost to the industries wastewater remain recalcitrant. Over the years epidemiological studies have shown the evidence that long-term occupational exposure to certain aromatic amines such as benzidine, 4-aminobiphenyl and 2-naphthylamine, that are used in dye industries increases the risk of developing cancer. Several of the dyes are mutagenic and carcinogenic

Table: Current physical and chemical technologies for colour removal Physical and/or chemical method Advantages Disadvantages Adsorption Good removal of a Absorbent requires regeneration wide variety of dyes or disposal Membrane Removes all dye types Concentrated sludge technologies production Coagulation/ Economically feasible High sludge production flocculation Oxidation Rapid process High energy costs Biological treatment is advantageous over the physical-chemical techniques as it is inexpensive and more environmental friendly

Materials and Methods Sample – 35 different samples were collected from various sites of Indore city. Samples from compost soil, Garage soil, Municipal waste water, Industrial waste water.

Materials and Methods Screening- Initial enrichment was carried out in Nutrient broth tubes containing 50 ppm dye. 1 g of soil was added to 10ml of distilled water and supernatant was used as inoculum. Tubes showing decolorization were used for further screening. The isolates were obtained by plating on Nutrient agar plates.

Materials and Methods Soil Type Day 1 Day 2 Day 3 Day 4 Garden soil 1 + ++ +++ ++++ Garden soil 2 Garden Soil 3 Sand Compost Soil 1 Compost Soil 2 Industrial waste water Municipal waste water 1 Municipal waste water 2 -

Isolates Soil Type Isolates I-3, I-4,I-1,I-2, I-16,I-23, Garden soil 1 I-3, I-4,I-1,I-2, I-16,I-23, Garden soil 2 I-15,A-14,A-15,A-16, Garden Soil 3 I-20, I-21,I-22 Sand I-13, I-17, A-6,A-7,A-8,A-13, Compost Soil 1 I-5, I-10,I-14, A-3,I-7, I-8,I-9,I-10,I-11,I-12 Compost Soil 2 I-25,I-26,I-27, I-28 Industrial waste water I-6, T-2,T-1,T-3 Municipal waste water 1 I-18,I-19,I-24, A11,A-12, A12a,

Materials and Methods The various colonies were identified and their colony characters were recorded. The potential of the isolates to decolorize the dye was further tested by observing their zone of inhibition on Nutrient agar plates containing 50 ppm.

Zone of Decolorization Isolates Colony Size Zone Size Zone of Decolorization I-3 8 mm 11 mm 1.37 I-4 10.3mm 13.3 mm 1.29 I-5 9 mm 12 mm 1.33 T-2 9.6 mm 1.25 I-21 1.2 I-18   7.6 mm 10 mm 1.3 I-25 I-13 12.3 mm 14.2 mm 1.1 I-8 8.6 mm 1.4 I-15 11.6 mm 1.5

Zone of Decolorization Isolates Colony Size Zone Size Zone of Decolorization A-1 7.3 mm 10.3 mm 1.41 A3   10 mm 13.3 mm 1.33 A-C3a   11.6 mm 14 mm 1.20 A-11  8 mm 1.28 A-13 9 mm 1.11 A-10  7.6 mm 1.04 I-17  9.6 mm 12.7 mm 1.32 I-27 18.3 mm 21 mm 1.14 I-22 11 mm 14.3 mm 1.3 I-28  30 mm 45 mm 1.5

Spectrophotometric analysis Isolate 0 hr After 120 hrs % age I -28 0.992 0.068 93.14% I -17 1.058 0.145 86.2% I -22 1.061 0.154 85.4% A-3 1.012 0.149 85.0% I - 8 1.018 0.153 84.9% A-5 1.068 0.210 80.3% I-18 0.981 0.250 72.6% I-3 0.989 0.360 62.5% I-15 0.969 59.7% I-25 0.439 54.9% A-1 0.978 0.560 40.5% I-5 1.014 0.632 39.0%

Four strains were then selected for further study and their decolorization time was determined. Isolate Time taken for decolorization I-28 8 h I-22 12 h I-17 30 h A-3 35 h

Conclusion