Waste water released from the use of synthetic dyes in different textile and other dye stuff industries require treatment before it is discharged into the environment to prevent groundwater contamination. Considerable interest has been on decolourisation and degradation of dyes by microorganisms due to their efficiency and duration of treatment.

1. BIODECOLOURISATION OF THE AZO DYE, CONGO RED USING
THE BACTERIUM, LACTOBACILLUS DELBRUECKII
Eljeeva Devakumari, *K. Balachander and A.Joseph Thatheyus
PG & Research Department of Zoology
*PG Department of Microbiology
The American College, Madurai – 625002
Tamil Nadu, India.

2. Introduction
 “Water”, the elixir of life – polluted – environmental hazards – rivers,
waterbodies.
 Textile industries – dyes – chemical effluents – treatment plants.
 Azo dyes – congo red – carcinogenic.
 Biodecolourisation – microbes – ecofriendly.

3. Effects
Textile
waste
water
Human
being
Fishes and sea
life
Ambient
environment
Plant life

4. Materials and Methods
 Isolation of the bacterial strain
 Dye selection
 Absorption maxima for the dye
 Inoculation of the Bacterial Strain
 Identification

5. Continued…
Decolourisation assay
D (%) = [(Aini - Afin) / Aini ] × 100
Where, D = Decolourization activity, Aini = Initial absorbance, Afin = Final absorbance
after incubation time.
Enzyme Assay
 α – amylase,
 Protease.

6. Results
Identification

7. Congo Red decolourisation using L.delbrueckii

8. Decolourisation of Congo Red using L.delbrueckii in short duration.
0
0.5
1
1.5
2
2.5
0 1 2 3 4 5 6 7 8
OPTICALDENSITYAT470NM
DURATION OF TREATMENT (HOURS)
10ppm 20ppm 40ppm 50ppm 100ppm 200ppm 500ppm 1000ppm

9. Decolourisation activity of Lactobacillus delbrueckii on Congo
Red in short duration.
0
2
4
6
8
10
12
14
1 2 3 4 5 6 7
Decolourization%
Durationn of Treatment (hours)
10ppm 20ppm 30ppm 40ppm 50ppm 100ppm 500ppm 1000ppm

10. Decolourisation activity of Congo Red using Lactobacillus
delbrueckii in long duration.
0
0.5
1
1.5
2
2.5
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
OPTICALDENSITYAT470NM
DURATION OF TREATMENT (DAYS)
10ppm 20ppm 40ppm 50ppm 100ppm 200ppm 500ppm 1000ppm

11. Decolourisation activity of Lactobacillus delbrueckii on Congo
red in long duration.
0
10
20
30
40
50
60
70
80
90
100
10ppm 20ppm 30ppm 40ppm 50ppm 100ppm 200ppm 500ppm 1000ppm
Decolurisatinactivity(%)
Dye Concentration (ppm)
Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Day 8 Day 9 Day 10 Day 11 Day 12 Day 13 Day 14 Day 15

12.  Enzyme production during decolorization process

13. α -amylase activity during decolourisation of Congo Red by
L.delbrueckii.
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
10 20 30 40 50
α-AmylaseActivity
Dye Concentration (ppm)
Day 1 Day 3 Day 5

14. Protease activity during decolourization of Congo red by
Lactobacillus delbrueckii.
0
50
100
150
200
250
300
1o 20 30 40 50
ProteaseActivity
Dye Concentration (ppm)
Day 1 Day 3 Day 5

15. Two way analysis of variance: Effect of Lactobacillus delbrueckii on the
decolourisation activity of Congo red in short duration and long duration.
Duration Source of
Variation
SS DF MS Calculated
F value
Table F
value at 5%
level
Level of
significance
Short Treatment
Period
0.030104 6 0.005017 0.941683217 2.294598289 NS
Dye
Concentration
17.2664 8 0.005017 411.1886172 2.138229149 S
Long Treatment
period
648.9853 15 43.26569 1.072265548 1.75049637 NS
Dye
concentration
312.3766 8 39.04707 0.96771439 2.01642714 NS

16. Summary

17. Conclusion
 Current study confirmed the decolourisation of the azo dye, congo red by the isolate
Lactobacillus delbrueckii under invitro conditions.
 Bacteria – adapting environment – producing enzymes – decolourisation – effective
method.

18. THANKYOU…….