exercise 15 - nitrogen and sulfur metabolism
TRANSCRIPT
![Page 1: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/1.jpg)
NITROGEN AND SULFUR METABOLISM
Reported By: Claire April M. Macabidang
![Page 2: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/2.jpg)
METABOLISMBiochemical reactions that take place inside a cell
Reactions involved: Anabolism – building up process of
energy Catabolism – breaking down process
of energy
![Page 3: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/3.jpg)
NITROGENEssential element of biological molecules
Constituent of amino acids, nucleic acids, nucleotides, and enzymes
![Page 4: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/4.jpg)
GENERAL VIEW OF NITROGEN METABOLISM
![Page 5: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/5.jpg)
PATHWAYS INVOLVED IN NITROGEN UTILIZATION
Protein Digestion
![Page 6: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/6.jpg)
PATHWAYS INVOLVED IN NITROGEN UTILIZATION
Oxidative Deamination
![Page 7: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/7.jpg)
PATHWAYS INVOLVED IN NITROGEN UTILIZATION
Reductive Deamination
![Page 8: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/8.jpg)
PATHWAYS INVOLVED IN NITROGEN UTILIZATION
Decarboxylation
![Page 9: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/9.jpg)
PATHWAYS INVOLVED IN NITROGEN UTILIZATION
Transamination Reactions
![Page 10: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/10.jpg)
PATHWAYS INVOLVED IN NITROGEN UTILIZATION
Nitrification
![Page 11: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/11.jpg)
PATHWAYS INVOLVED IN NITROGEN UTILIZATION
Denitrification
![Page 12: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/12.jpg)
SULFUREssential component of all living cells
Constituent of cysteine, methionine, glutathione, and several coenzymes
![Page 13: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/13.jpg)
TEST PERFORMEDA. Utilization of Organic and Inorganic
NitrogenB. Urea HydrolysisC. Indole Production from TryptophanD. Phenylalanine Deamination TestE. Lysine Decarboxylase TestF. Nitrate ReductionG. Hydrogen Sulfide (H2S) Production
![Page 14: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/14.jpg)
Utilization of Organic and Inorganic Nitrogen
![Page 15: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/15.jpg)
Purpose
Determines the type of nitrogen (inorganic or organic) a bacterium
can utilize
![Page 16: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/16.jpg)
Medium UsedNitrogen Test Media A
Potassium nitrate (KNO3) Inorganic nitrogen source Mineral niter and natural solid nitrogen
source Used in fertilizers, as a source of nitrogen
and potassium (2 of the macronutrients for plants)
Growth indicates that the organism is capable of using INORGANIC nitrogen
![Page 17: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/17.jpg)
Medium UsedNitrogen Test Media A
These organisms are called NITROGEN – FIXING BACTERIA
Nitrogen is reduced to ammonia by the enzyme nitrogenase
![Page 18: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/18.jpg)
Medium UsedNitrogen Test Media B
Sodium glutamate or “Vetsin” Organic nitrogen source Exists naturally in all living things One of the building blocks of proteins Found in "free form“, not bound to
other molecules
Growth indicates that bacteria can metabolize ORGANIC nitrogen
![Page 19: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/19.jpg)
Urea Hydrolysis
![Page 20: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/20.jpg)
Purpose
Detects presence of urease enzyme that catalyze the hydrolysis of urea
![Page 21: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/21.jpg)
Medium UsedUrea Broth
Urea – nitrogen sourcePotassium phosphates – bufferYeast extract – vitamins sourcePhenol red – pH indicator
![Page 22: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/22.jpg)
Principle Urea produces ammonia when acted upon by
urease
Ammonia increases the pH of the medium Phenol red: Orange to pink or red color
pH 6.8 to 7 – orange pH 8.1 – pink or red
![Page 23: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/23.jpg)
Results
Color change from orange to dark pink or red
Proteus vulgaris (+)Escherichia coli ()
![Page 24: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/24.jpg)
Results
![Page 25: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/25.jpg)
Indole Production from Tryptophan
![Page 26: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/26.jpg)
Purpose
Test for the ability of the organism to degrade tryptophan with the aid of
the enzyme tryptophanase
![Page 27: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/27.jpg)
Medium UsedTryptone Broth
an enzymatic digest of casein used as nitrogen source
Tryptone – source of tryptophan
![Page 28: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/28.jpg)
Reagent UsedKovac’s Reagent-dimethylaminobenzaldehyde – reacts with indole
Amyl alcohol (Butanol) – acts as solvent
Hydrochloric acid (HCl) – hasten extraction of indole
![Page 29: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/29.jpg)
Principle The enzyme tryptophanase can
degrade tryptophan into indole, ammonia, pyruvic acid
Ammonia and pyruvate is metabolized Indole is not metabolized and stay in
the medium
![Page 30: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/30.jpg)
Principle Upon addition of Kovac’s reagent, the
amyl alcohol (butanol) component dissolves the indole which then reacts with p-dimethylaminobenzaldehyde, producing red rosindole dye
![Page 31: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/31.jpg)
Results
Formation of red colored ring at the surface of the medium after the
addition of Kovac’s reagent
Escherichia coli (+)Proteus vulgaris (+)
Enterobacter aerogenes ()
![Page 32: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/32.jpg)
Results
![Page 33: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/33.jpg)
Phenylalanine Deamination
![Page 34: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/34.jpg)
Purpose
Test for the presence of the enzyme deaminase or amino acid oxidase
![Page 35: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/35.jpg)
PurposeDeamination – oxidation of an amino acid
Principle: Before an amino acid can be used by the cell as an energy source, the amino group must be removed
![Page 36: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/36.jpg)
Medium UsedPhenylalanine Agar
A.K.A. Phenylalanine deaminase medium
Used to differentiate members of the genera Proteus, Morganella (which were originally classified under the genus Proteus), and Providencia from other Enterobacteriaceae
![Page 37: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/37.jpg)
Medium UsedPhenylalanine Agar
DL – phenylalanine Yeast extract – nutrient and vitamin
source for growth Sodium chloride (NaCl) – supplies
essential electrolytes for transport and osmotic balance
Dipotassium hydrogen phosphate (K2HPO4)– buffer
Agar – solidifying agent
![Page 38: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/38.jpg)
Reagent Used10% Ferric chloride (FeCl3)
Oxidizing reagent Acts as an chelating agent (a substance used to reduce the concentration of free metal ion in solution by complexing)
![Page 39: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/39.jpg)
Principle Phenylalanine in the medium is
deaminated by phenylalanine deaminase to phenylpyruvic acid
The enzyme phenylalanine deaminase will remove the amine group (NH2) from phenylalanine and release it as free ammonia (NH3)
![Page 40: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/40.jpg)
Principle This leaves phenylpyruvic acid, which
can be detected by adding an oxidizing reagent such as ferric chloride
10% Ferric chloride (FeCl3) combines with phenylpyruvic acid to form green color
![Page 41: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/41.jpg)
Results
Formation of intense green color upon the addition of 10% Ferric
chloride (FeCl3) solution
Proteus vulgaris (+)Escherichia coli ()
Enterobacter aerogenes ()
![Page 42: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/42.jpg)
Results
![Page 43: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/43.jpg)
Lysine Decarboxylation
![Page 44: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/44.jpg)
Purpose
Test for the presence of the enzyme lysine decarboxylase which converts
lysine to amine (cadaverine)
![Page 45: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/45.jpg)
Purpose Decarboxylation - removal of a carboxyl
group from an organic molecule
![Page 46: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/46.jpg)
Medium Used Lysine Decarboxylase Broth
L – lysineDextrose – fermentable carbohydrate
Yeast extract – vitamins sourcePeptone – nitrogen and nutrient source essential for growth
Bromcresol Purple – pH indicator
![Page 47: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/47.jpg)
PrincipleUnable to ferment dextrose = No color change
Able to ferment the dextrose = Formation of acidic by – products and yellowing of the medium
Low pH and presence of the amino acid will stimulate decarboxylation
![Page 48: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/48.jpg)
Principle Lysine is converted to cadaverine Increase in the pH of the medium
changes its color from yellow back to purple
![Page 49: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/49.jpg)
Results
Red or purple color of the medium
Escherichia coli (+)Proteus vulgaris ()
![Page 50: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/50.jpg)
Results
![Page 51: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/51.jpg)
Nitrate Reduction
![Page 52: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/52.jpg)
Purpose
Detection for the presence of the enzyme reductase
![Page 53: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/53.jpg)
Medium UsedNutrient Broth with 0.1% Potassium Nitrate (KNO3) Nitrate source Nutrients
![Page 54: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/54.jpg)
Reagent UsedNitrate Reagent A
Acetic acid and Sulfanilic acid
Nitrate Reagent B Acetic acid and Alpha – naphthol
![Page 55: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/55.jpg)
Principle If reductase is present in the bacteria,
nitrate present in the broth is reduced to nitrite and furthermore into nitric oxide, nitrous oxide or N2
Denitrification – process of nitrate reduction
![Page 56: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/56.jpg)
Principle Gas inside the Durham tube – mixture of
carbon dioxide (CO2) and nitrogen (N2) released from the reduction of nitrate
![Page 57: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/57.jpg)
Principle The presence of nitrite is detected by the
addition of Nitrate Reagent A and Nitrate Reagent B
![Page 58: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/58.jpg)
Principle The Nitrate Reduction Test is based on
the detection of nitrite and its ability to form a red compound when it reacts with sulfanilic acid (Nitrate Reagent A) to form a complex (nitrite – sulfanilic acid) which then reacts with a – naphthylamine (Nitrate Reagent B) to give a red precipitate (Prontosil)
Zinc dust catalyses the reduction of nitrate to nitrite
![Page 59: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/59.jpg)
![Page 60: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/60.jpg)
Results
![Page 61: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/61.jpg)
Results
![Page 62: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/62.jpg)
Results
![Page 63: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/63.jpg)
Results Gas Production – reduction of nitrate
Upon addition of Nitrate Reagent A and Nitrate Reagent B – red color Presence of nitrite
*** If no color change: Nitrate is not reduced to nitrite Nitrate is reduced to a different form
other than nitrite
![Page 64: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/64.jpg)
ResultsUpon addition of Zinc dust – no color change N2 is present Nitrate is reduced
*** If red color was observed: Nitrate is still present and reduced
by zinc
![Page 65: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/65.jpg)
Results
![Page 66: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/66.jpg)
Hydrogen Sulfide (H2S) Production
![Page 67: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/67.jpg)
Purpose
Detection for the presence of the enzyme cysteine desulfonase which
helps in synthesizing hydrogen sulfide from the peptones in the
medium
![Page 68: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/68.jpg)
Medium Used Lead Acetate Agar
Lead acetate – reacts with hydrogen sulfide (H2S)
Peptone – source of organic sulfur-containing compound cysteine
DextroseSodium thiosulfate – inorganic sulfur source
Agar – solidifying agent
![Page 69: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/69.jpg)
Principle Hydrogen sulfide is produced when
amino acids containing sulfur are metabolized by microorganisms
If the medium contains metallic ions (lead, bismuth , or iron), the hydrogen sulfide formed during growth combines with the metallic ions to form metal sulfide that blackens the medium
![Page 70: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/70.jpg)
Principle Lead acetate in the medium reacts with
H2S forming black precipitate (lead sulfide)
![Page 71: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/71.jpg)
Results
Formation of black or brown precipitate in the medium
Proteus vulgaris (+)Escherichia coli ()
![Page 72: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/72.jpg)
Results
![Page 73: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/73.jpg)
STUDY QUESTIONS
![Page 74: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/74.jpg)
QUESTIONWhat controls the ability of an organism to
utilize certain types of nitrogen sources?
Bacteria vary widely in their ability to utilize various sources of nitrogen for synthesis of proteins
Enzymes present in a bacteria Genetically determined
![Page 75: Exercise 15 - Nitrogen and Sulfur Metabolism](https://reader033.vdocument.in/reader033/viewer/2022061106/54472447b1af9f760a8b4662/html5/thumbnails/75.jpg)
REFERENCES http://www.mesacc.edu/~johnson/labtools/Dbi
ochem/urea.jpg http://biosci.usc.edu/courses/2002-fall/docum
ents/bisc300-lab_Urea_Hydrolysis.jpg http://lh3.ggpht.com/-cC8H3nZwCuU/TDT7FSI
Z0kI/AAAAAAAAALw/dw9IhYM9dsA/INDOLE.JPG
http://academic.missouriwestern.edu/jcbaker/images/PD.jpg
http://www.google.com.ph/#hl=en&gs_nf=1&pq=k2hpo4&cp=9&gs_id=14&xhr=t&q=chelating+agent&pf=p&biw=1280&bih=691&sclient=psy-ab&oq=chelating&aq=0&aqi=g4&aql=&gs_sm=&gs_upl=&gs_l=&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=43e7b3983c4556bc
http://en.wikipedia.org/wiki/Metabolism http://www.cdc.gov/std/gonorrhea/lab/tests/nit
rate.htm