BIODEGRADATION OF TEXTILE DYES BY BACTERIA

1. BIODEGRADATION OF TEXTILE DYES BY BACTERIA
UZMA SARFRAZ

2. INTRODUCTION
• The textile industry covers two-third of the gross dye
stuff market.
• During manufacturing and usage, approximately 10-
15% of the dye is lost directly to wastewater that
finds its way into the environment.
• The unused dyes and chemicals are discharge as dye
effluent from various units.
• Dyeing and finishing stages are major contributor
• Bacteria are known to degrade and mineralize many
reactive azo dyes faster.

3. Common Methodology
For Bacterial Treatment
Autoclaved mineral salt + textile waste effluent(L) in a
bioreactor
Add inoculum (ml) aseptically to make working
solution (L)
Stirring at room temperature with agitation speed
(rpm)
Fermentation (days)
Calculation (Decolorization % = Din –Df Din *100) and
Analysis of decolorization
Filtration of solution through Whattman filter paper
and centrifugation(minutes)

4. Bacterial Biodegradation
Mechanism of Textile Dyes

5. CHARACTERIZATION TECHNIQUES
Technique Main function
UV-vis Spectrophotometry Dye decolorization
GC-MS Identification of metabolites
H NMR and SEM Morphology and for the structure of
its molecule
FTIR, HPLC and HPTLC analysis Confirmation of degradation of
metabolites

6. Anaerobic Conditions
• The enzyme azoreductase functions.
• NADH and FADH are the reducing agents.
• Oxygen possibly, inhibit the azo bond reduction activity, as aerobic respiration
utilizes NADH, thus impeding the electron transfer from NADH to azo bonds.
• Decolorization might be attributed to nonspecific extracellular reactions
occurring between reduced compounds generated by the anaerobic biomass.
• Decolorization is mediated by methanogens and acidogenic, as well as
methanogenic bacteria.
• It is a nonspecific process, depending on the carbon source and the dye
structure.
• Some bacteria taking part in the decolorization process could grow aerobically;
however, decolorization is achieved only under anaerobic conditions.

7. Decolorization under Aerobic Conditions
• Most bacteria that degrade dyes under aerobic conditions cannot
utilize the dye as a carbon source and require an additional carbon
source.
• Very few bacteria are capable of growing on azo compounds as the
sole carbon source.
• These bacteria are able to cleave –N=N– bonds and utilize amines for
their growth, for instance, Pigmentiphaga kullae K24 and Xenophilus
azovorans KF 46.
• Aerobic bacteria possess oxidoreductive enzymes and can break the
dye molecules symmetrically or asymmetrically.
• They could also bring about deamination, desulfonation,
hydroxylation, etc.
• Therefore, different dye structures can be broken down by anaerobic
bacteria.

8. Decolorization under Anoxic Conditions
• Anoxic conditions have less than 0.5 mg/L dissolved oxygen.
• Operating conditions for these are similar to aerobic
treatments.
• NADPH carries more electrons for reduction.
• Mixed bacterial populations of aerobic and facultative
anaerobic have been shown to be useful in anoxic
decolorization of various dyes.
• This requires complex organic sources, which increases the
cost.

9. Bacterial strains Dye and its concentration Conditions Decolorization (%) Time
Bacillus sp. Blue 2B temperature 40°C and pH
7
60% 48 h
Bacillus sp. Acid Orange 7 Temperature 370°C 73% 3 days
Bacilluscereus (BN-7), Pseudomonas putida
(BN-4), Pseudomonas fluorescence (BN-5)and
Stenotrophomonas acidaminiphila (BN-3)
AcidRed88 AcidRed119, AcidRed97,
AcidBlue113, ReactiveRed120;(6 mgL-1 )
7.0,35,100 rpm 78, 99, 94, 99,and
82.
24 hours
Bacilluscereus (BN-7), Pseudomonas putida
(BN-4), Pseudomonas fluorescence (BN-5)and
Stenotrophomonas acidaminiphila (BN-3)
AcidRed88 AcidRed119, AcidRed97,
AcidBlue113, ReactiveRed120;(6 mgL-1 )
7.0,35,100 rpm 78, 99, 94, 99,and
82.
24 hours
Mixed bacterial consortium JW-2 ReactiveViolet5R;(100 mgL-1 6.5–8.5,25–37,static 100 36hrs
Bacterial consortium SV Ranocid Fast Blue; (100 mgL-1) 7.0,37,static 100 24hrs
Bacterial consortium DMC Direct Black 22 ;(100 mgL-1) 7.0,45,static >91 12hrs
Bacterial consortium-GR (Proteus vulgaris and
Miccrococcus glutamicus)
Green HE4BD, mixture of 6 reactive dyes;
(50 mgL-1each)
8.0,37,static 100 24hrs
Penicillium sp. QQ and bacterial Sphingo
monasxenophaga QYY
Reactive Brilliant red X-3B and Acid Red B;
(50 mgL-1)
3.0,30,static 87.8 72hrs

10. Bacterial Mediated Biodecolorization Of Wastewater Containing Mixed Reactive Dyes Using
Jack-fruit Seed As Co-substrate
• Decolorization of azo (reactive red-21 and reactive orange-16), and
anthraquinone (reactive blue-19) dyes using jack-fruit seed powder as co-
substrate.
• Pseudomonas aeruginosa SVM16
• The effect of process parameters on decolorization was done by response
surface methodology.
• The results of decolorization of individual dye solution of reactive red-21,
reactive orange-16, and reactive blue-19 is 97.7 %, 98.9 %, and 92.6 %.
• The jack-fruit seed supplemented decolorization process reveals that
treated water has shown lesser residual organic and color loading
compared to treated water obtained from bio-decolourization process
using yeast extract or other chemicals as co-substrate.
• With FTIR, GC-MS, and 1 H NMR showed the complete mineralization of
dye molecules.
• Non-toxicity of treated water proves through positive germination test
of Vigna radiata seeds.

11. UV-visible transmittance spectra of treated and untreated dye solution

12. H NMR spectra: (a) RO16 dye solution; (b) JFS solution; (c) untreated RO16
and JFS mixed solution; (d) treated mixed solution

13. Germinated green gram seed in treated water samples: (a) treated mixed RR21 and RO16 dye
contaminated water sample; (b) treated mixed RR21, RO16 and RB19 dye contaminated dye water
sample; (c) untreated textile wastewater; (d) treated textile wastewater.

14. Conclusion
 Bacterial decomposition of the wastewater is a viable option, as they do
not produce large amounts of sludge, have no adverse effect on the
environment, and are inexpensive
 Bacteria species (Gammaproteobacteria, Betaproteobacteria, and Bacilli
Aspergillus niger, Pseudomonas fluorescence, Proteus morganii, Fusarium
compacticum, Pseudomonas nigificans & Pseudomonas gellucidium )
have a significant potential for dye decolourization and degradation
 Mixed bacterial consortium utilization for textile dyes is a better option,
that can effectively tolerate the stress conditions more than the single
bacterial species.