Action on xenobiotics ppt biodegradation enhance biodegradation definition of xenobiotic compounds hazards of xenobiotics biodegradation ppt biodegradation of xenobiotics discovery of xenobiotics process of xenobiotics aerobic biodegradation and much more

1. ACTION ON
XENOBIOTICS
BIODEGRADATION
ENHANCE
BIODEGRADATION

2. DEFINITION OF XENOBIOTIC
COMPOUNDS
•The man made chemical present in the nature at
high concentration polluting the environment
are known as xenobiotics .
•Foreign to body .
•Not naturally produced.

3. HAZARDS OF XENOBIOTICS
•Highly toxic in nature.
•Causing skin problems and various types of
cancers .
•They are easily not degraded so they remain in
environment for many years.

4. BIODEGRADATION
•The mechanisms by which substances
are decomposed by living organisms
(bacteria, fungi) is called
biodegradation.

5. BIODEGRADATION OF XENOBIOTICS
•MICROBES are utilized to decompose the
xenobiotic compounds .
•ECO friendly and economical .
•Process results in energy production.

6. DISCOVERY
•The microbial biodegradation of
xenobiotics was proposed by
ALEXZENDER 1965.

7. FACULTATIVES OF THE PROCESS
• Each step is catalyzed by specific enzyme.
CONDITIONS:
• Degradation of some xenobiotics depends on the
presence of specific compound.

8. PROCESS
• Microbes apply xenobiotics as their substrate .
• They grow on them.
• They secrete organic acids and enzymes and they
degrade them .
• They convert them into energy and carbon dioxide.

9. BIODEGRADATION OF XEBOBIOTICS COMPOUNDS
• The microbes uses two modes of actions on
xenobiotics.
• 1 # AEROBIC BIODEGRADATION
• 2 # ANAEROBIC BIODEGRADATION

10. AEROBIC BIODEGRADATION
•It requires excess oxygen gas .
•Bacterial species like Pseudomonas, Bacillus ,
Rhodococcus etc.

11. AEROBIC BIODEGRDATION PATHWAY
• Some of the xenobiotics like petroleum hydrocarbons,
benzene, toluene, phenol etc are degraded by the
aerobic degradation process .
• Many bacterial are capable to grow on these
chemicals .
• They are producing enzymes which degrade toxic
compounds to nontoxic compounds.

12. ENZYMES INVOLVED
•MICROBIAL OXYGENASE : Two types
•MONOOXYGENASE : single oxygen atom
•DIOXYGENASE : two oxygen atoms

13. AEROBIC BIODEGRADATION
•Xenobiotic compound + O2 ----)
CO2 + H2O + biomass + residue(s)

14. ANAEROBIC BIODEGRADATION
•It takes place in absence of oxygen.
•Bacterial species like Methanospirillum ,
Methanosaeta etc.

15. ANAEROBIC BIODEGRADATION
PATHWAY
• Some pollutants are not mineralized by an aerobic
degradation process pesticides like DDT.
• The compounds are resistant to degradation because
of increase in halogen character.
• During anaerobic degradation reductive
dehalogenation is the first step of degradation .

16. ANAEROBIC BIODEGRADATION
PATHWAY• The anaerobic degradation process is a
renewable energy source, biogas generated from
anaerobic digestion. It’s mainly consist methane .
• Xenobiotic compound ---) CO2 + CH4 +
H2O + biomass + residue(s)

17. ENZYMES
•Microbial Dehalogenases:
degradation of chlorinate
pollutant