MICROBIAL TRANSFORMATION OF

NON-STEROIDAL COMPOUNDS &

PESTICIDESKOMAL VERMA

ROLL NO.3599

MDU-UIET

WHAT ARE NON-STEROIDAL

COMPOUNDS?

• An organic compound that doesn’t contain steroid is non- steroid.

• For eg. Diethylstibesterol . Stilbesterol, DES –synthetic nonsteroid with the property of estrogen : formerly used to used to treat menstrual problems but found to associate with vaginal cancers in the daughters of woman so treated during pregnancy .

Different types of Non-Steroidal

compounds :

• L-Ascorbic Acids

• Dihydroxyacetone

• Prostagladins

What is Microbial Transformation ??

• “Transformation” refers to a change in the heritable characteristics in bacteria that have been incubated with DNA and Other bacteria .

• Micro-organisms have the ability to chemically modify a wide variety of organic compound. Such changes are called Microbial Transformations.

Microbial Transformation Reactions

1. Oxidation

2. Reduction

3. Hydrolysis

4. Condensation

5. Isomerization

Oxidoreductases

Hydrolases

Aldol Condensation

Isomerases

OXIDATION REACTION

• OXIDATION REACTION is a reaction in which a chemical looses electrons.

• The simplest type of oxidation reaction is dehydrogenation.

REDUCTION REACTION

• In which substrate gain electron. These reactions most likely occure with xenobiotics in which oxygen content is low.

• Eg. :- Azoreduction , dehalogenation.

HYDROLYTIC REACTION

• In which addition of water splits the toxic into fragments or smaller molecules eg. Larger chemicals such as esters , amines , hydrozine are made by this.

ALDOL CONDENSATION REACTION

• An aldol condensation is an organic reaction in which an enol or an enolate ion reacts with a carbonyl compound to form a β-hydroxyaldehyde or β-hydroxyketone, followed by a dehydration to give a conjugated enone

ISOMERIZATION REACTION

• In chemistry isomerization (also isomerisation) is the process by which one molecule is transformed into another molecule which has exactly the same atoms, but the atoms are rearranged e.g. A-B-C → B-A-C (these related molecules are known as isomers [1]).

ALKYLATION REACTION

• Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion or a carbene (or their equivalents).

L-Ascorbic acid(Vitamin C)

• Reichstein-Grussner synthesis is the process for producing L-Ascorbic acid.

• In this process consists of several chemical steps and one microbial conversion.

• L-ascorbic acid used in vitamin preparation or as an antioxidant in food manufacture.

• Production is about 40,000 tons per year.

OXIDATION STAGE

• D-sorbitol to L-sorbose is carried out by Acetobacter suboxydans in a submerged process at 30-35 C .

• Sorbitol is added at an initial concentration of 20 % to a nutrient solution consisting of 0.5% yeast extract or corn steep liquor and CaCO3.

• After 24 hours quantitative conversion is completed.

Microbial dehydration of

D-sorbitol to L- sorbitol in

the production of L-

ascorbic acid

1. D- Glucose

2. D- Sorbitol

3. L-sorbose

4. L-Ascorbic acid

5. Sodium Salt /EnolForm / 2-keto-L-gluconic acid

6. 2-Keto-Lgluconic acid

Two step fermentation STEPS

• 1st step- OXIDATION of GLUCOSE by an Erwiniaspecies to 2,5-diketo-D-gluconic acid(2,5-DKG) via D-Gluconic acid and 2-keto-D-Gluconic acid.

• 2nd step-REDUCTION of 2,5-DKG to 2-keto-gulonic acid, is catalyzed by a Cornybacterium sp. And after 16 hours Cornybacterium is grown and fed with sterlized Erwinia culture.

• After 66 hours incubation,106 g of calcium 2-keto-L-gulonate is formed 92% and latter transformed into L-ascorbic acid.

DIHYDROXYACETONE FROM GLYCEROL

Microbial conversation of glycerol to

Dihydroxyacetone :• Dihydroxyacetone is used in suntan lotions and

cosmetics.

• Various acetic acid bacteria convert 10% glycerol in a suitable nutrient solution (0.5% yeast extract ,0.5% KH2PO4, 2% CaCO3) at 28 C and at a pH below 6.0.

• Conversion time is 72-96 hours and reduced to 33 hours with Gluconobacter melanogenus IFO 3293 by using O2-enriched air.

PROSTAGLANDINS

• Prostaglandins are unsaturated C20 fatty acids that function as tissue hormones, have increasing medical significance because of their varied physiological activities.

• Marketed are PGE2 as a contraceptive,for the alleviation of pain of childbirth, PEG1 for the treatment of congenital heart failure and PEG1 derivatives for the treatment of digestive diseases.

• The Prostaglandins PGE1,PGE2,PGF1 and PGF2 can be produced from unsaturated fatty acids by microbial transformation with fungi.

Biotransformation of arachidonic acid to prostagladins

WHAT IS A PESTICIDE ?

• A Pesticide is a chemical which are used to kill the unwanted microrganisms, pest and nematodes

• Pesticides contain active ingredients and inert ingredients.

• ACTIVE INGREDIENTS- The substances that perform the desired effect of the pesticides.

• INERT INGREDIENTS- The substances that are mixer with active ingredient to create the final product.

DIFFERENT KINDS OF PESTICIDES

• BIOPESTICIDES

• INSECTICIDES

• HERBICIDES

• ANTISEPTICS

• DISINFACTANTS

• SANITIZERS

NEED OF TRANSFORMATION OF

PESTICIDES• Pesticide transformations can be by both

chemical (such as hydrolysis and photolysis) and biological (primarily microbial metabolism).

• Degradation (or decomposition/breakdown) is the result of a change in molecular structure resulting in a lower molecular weight.

• Hazardous to the environment, occur mainly in soil and water.

MAIN PROCESSES OF MICROBIAL

TRANSFORMTION4 PROCESSES INVOLVED ARE:

• BIODEGRADATION

• COMETABOLISM

• CONJUGATION

• ACCUMULATION

BIODEGRADATION

• XENOBIOTICS serve as substrate for microbial growth and energy production.

• Complete breakdown of some substances to CO2 and H2O .

• The herbicide DALAPON, chlorinated fatty acid which is coverted by Arthrobacter sp. Into pyruvate after oxidative dehalogenation.

COMETABOLISM

• In this microrganisms don’t obtain energy from transformation reaction and require another substances for growth.

• It results in modification of molecules by either decreasing and increasing in toxicty.

• The pesticides is transformed by metabolic reactions but does not serve as an energy source.The rate of transformation does not increase with time or with further additions.

COMETABOLISM OF PESTICIDES

SUBTRATECONVERSION PRODUCT & MICRORGANISM

• Chlorobenzilate(ethyl-4,4’-dichlorobenzilate)

• Chloroneb(1,4-dichloro-2,5-dimethoxy-benzene)

• DDT

• 2,4,5-Trichlorophenoxyacetate

• 3,5-Dichlorcatechol

• 4,4’-Dichlorobenzophenone

(Rhodotorula gracilis)

• 2,5-Dichlor-4-methoxyphenol(Fusarium sp.)

• p,p’-dichlordiphenylmethane(Aerobacter aerogenes)

• 3,5-Dichlorcatechol (Brevibacterium sp.)

• 3,5-Dichlor-2 hydroxymuconicacid semialdehyde(Achromobactersp.)

DEHALOGENATION REACTION

• Dehalogenation reaction or oxidative dehalogenation reactions are important cometabolism reactions which make pesticide molecules accessible for further breakdown.

• Some compounds like chlordecone, a hexachlorocyclopentadiene derivative with excellent insecticide effects as it has complicated structure and high degree of halogenation.

DDT TDE

Reductive dehalogenation :

Dehydrodehalogenation :

DDT DDE

Transformation of the chlorinated hydrocarbon DDT

CONJUGATION REACTION

• Linkage of xenobiotics or decomposition with naturally occuring compounds such as amino acids or carbohydrates result in detoxification.

• The conversion of a dithiocarbamate fungicide into keto acid and aminobutyric acid.

ACCUMULATION REACTION

• When microrganisms absorb xenobiotics,onlytemporary detoxification of the environment occurs.

• It is found that microrganisms and plankton absorb DDT and then it is stored in fat tissues,leading to an even greater concentration factor.

• The end result is an accumulation of the compound to high levels as it passes up the food chain.

THANKYOU VERY MUCH FOR YOUR ATTENTION.