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

2. 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.

3. 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

4. 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

5. 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.

7. 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.

8. 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 -

9. 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,

11. 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.

12. 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

13. 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

14. 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%

15. 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

16. Conclusion