Biologic requirements of the bacterial cell

1. BIOLOGIC REQUIREMENTS OF
THE BACTERIAL CELL

2. • I. ATMOSPHERIC REQUIREMENTS---USEFUL IN
IDENTIFYING BACTERIA:
• A. RELATIONSHIP TO OXYGEN:
• 1. OBLIGATE AEROBES---REQUIRE OXYGEN
CONCENTRATIONS COMPARABLE TO THAT
FOUND IN ROOM AIR (20-21% O2)
– * Mycobacteria
– * certain fungi

3. • 2. MICROAEROPHILES---REQUIRE OXYGEN
CONCENTRATION LOWER THAN THAT AT
ROOM TEMP. FOR MULTIPLICATION( 5% O2)
– * Neiserria gonorrheae
– * Campylobacter
3. ANAEROBES---DO NOT REQUIRE OXYGEN
FOR LIFE AND REPRODUCTION; MAY VARY
IN THEIR SENSITIVITY TO OXYGEN

4. – A. OBLIGATE ANAEROBE---CAN GROW IN AN
ENVIRONMENT CONTAINING NO OXYGEN
– B. AEROTOLERANT ANAEROBE---DOES NOT
REQUIRE OXYGEN, GROWS BETTER IN THE
ABSENCE OF OXYGEN BUT CAN SURVIVE IN
ATMOSPHERES CONTAINING MOLECULAR OXYGEN
(AIR/ CO2 INCUBATOR)
– C. FACULTATIVE ANAEROBES---CAPABLE OF
SURVIVING IN EITHER THE PRESENCE OR ABSENCE
OF OXYGEN (0 % O2 TO 20 TO 21% O2)

5. – ***MEMBERS OF ENTEROBACTERIACEAE/
STREPTOCOCCI/ STAPHYLOCOCCI
– D. CAPNOPHILES---GROW BETTER IN THE
PRESENCE OF INCREASED CONCENTRATIONS OF
CO2
– EX. ANAEROBES---BACTEROIDES/FUSOBACTERIUM
– AEROBES----NEISSERIA/CAMPYLOBACTER/
HAEMOPHILUS

6. • II. NUTRITIONAL REQUIREMENTS
• * PROTEINS---COMPRISES 50% OF THE BACTERIAL
CELL
• ***CARBON/HYDROGEN/OXYGEN/SULFUR/PHOS
PHORUS/NITROGEN
• ***POTASSIUM/CALCIUM/IRON/MANGANESE/M
AGNESIUM/COBALT/COPPER/ZINC/URANIUM (
SPECIAL ELEMENTS REQUIRED BY BACTERIA)
• ***FASTIDIOUS----ORGANISMS WITH SPECIALLY
DEMANDING NUTRITIONAL REQUIREMENTS

7. • * GROWTH FACTORS
• * SOURCES OF ENERGY
• ***ALL BACTERIA DERIVE THEIR CARBON AND
NITROGEN FROM ORGANIC MATTER, EXCEPT
THE SAPROPHYTES
• KINDS OF ORGANISMS ACCDG. TO WHERE
NOURISHMENT IS OBTAINED:
• 1. SAPROPHYTES---FROM NON-LIVING
ORGANIC MATTER

8. • *** PARASITES---DEPEND ON LIVING MATTER
FOR SUSTENANCE
• *** FACULTATIVE SAPROPHYTES---USUALLY
OBTAIN NOURISHMENT FROM LIVING MATTER
BUT MAY OBTAIN IT FROM THE DEAD ORGANIC
MATTER.
• ***FACULTATIVE PARASITES---USUALLY OBTAIN
THEIR NOURISHMENT FROM DEAD ORGANIC
MATTER BUT MAY OBTAIN IT FROM LIVING
MATTER.

9. • ***HETEROTROPHS/ ORGANOTROPHS--- OBTAIN
THEIR NUTRIENTS BY BREAKING DOWN ORGANIC
MATTER INTO SIMPLER INORGANIC SUBSTANCES.
• MOISTURE___75-80 % OF BACTERIAL CELL IS
WATER; NEEDED TO DISSOLVE FOOD MATERIALS
IN THE ENVIRONMENT
• DRYING---DETRIMENTAL TO BACTERIA GROWTH

10. • TEMPERATURE:
• *** OPTIMUM TEMP----BEST TEMP FOR
GROWTH
• *** MINIMUM TEMP.---LOWEST TEMP. AT
WHICH SPORES WILL GROW.
• ***MAXIMUM TEMP. HIGHEST TEMP AT
WHICH GROWTH IS POSSIBLE.

11. • *** 42-45 DEGREES CELCIUS IS THE HIGHEST
TEMP WHERE BACTERIA CAN STILL MULTIPLY;
20 DEGREES CELCIUS---LOWEST TEMP AT
WHICH THEY CAN MULTIPLY
• ***THERMOPHILES---HEAT-LOVING SPECIES;
CAN GROW ABOVE 45 DEGREES CELCIUS
TEMP.

12. • PSYCHROPHILES/CRYOPHILES---COLD-LOVING
SPECIES;CAN GROW AT TEMP JUST ABOVE THE
FREEZING POINT
• ***COLD RETARDS OR STOPS BACTERIAL
GROWTH THUS EMPLOYED IN THE PROCESS
OF REFRIGERATION IN ORDER TO PROLONG
THE SPOILAGE OF FOOD

13. Ph---refers to the acidity/alkalinity of
the medium
• ***PREFERRED PH IS BETWEEN 6-8
• **BEST PH FOR PATHOGENS IS PH 7
(NEUTRAL)
• OXYGEN REQUIREMENT:
• ***AEROBES--- GROW IN THE PRESENCE OF
FREE ATMOSPHERIC OXYGEN

14. • OBLIGATE AEROBES---CANNOT DEVELOP IN THE
ABSENCE OF FREE OXYGEN
• * ANAEROBES---OBTAAIN THEIR OXYGEN FROM
OXYGEN CONTAINING COMPOUNDS LIKE
INORGANIC SULFATES, NITRATES, CARBONATES
OR FROM ORGANIC COMPOUNDS
• * OBLIGATE ANAEROBES---ORGNISMS WHOSE
ENZYME SYSTEMS ARE INACTIVATED BY
ATMOSPHERIC OXYGEN

15. • * FACULTATIVE ORGANISMS---ADAPTABLE
EITHER TO THE PRESENCE OR ABSENCE OF
ATMOSPHERIC OXYGEN
• * MICROAEROPHILES---ORGANISMS THAT CAN
GROW EVEN IIN LOWERED OXYGEN CONTENT
IN THE AIR
• * CAPNOPHILES---NEED 3-10 % INCREASE IN
CARBON DIOXIDE CONTENT IN THE AIR TO
INITIATE DEVELOPMENT

16. LIGHT REQUIREMENTS:
• RED/ YELLOW----LITTLE BACTERICIDAL EFFECT
• *GREEN---HAVE LESS KILLING ACTION
• *VIOLE/ULTRAVIOLET/ BLUE---LIGHT
WAVELENGTHS THAT ARE HIGHLY
DESTRUCTIVE TO THE BACTERIAL CELL
• ** SOME SAPROPHYTIC SPECIES USE LIGHT
FOR AUTOTROPHIC ACTIVITY

17. BY-PRODUCTS OF BACTERIAL GROWTH
• BACTERIAL METABOLISM---DEPLETES FOOD
SUPPLY & RELEASE PRODUCTS THAT INHIBIT
FURTHER BACTERIAL GROWTH
• EX. PRODUCTION OF ORGANIC ACIDS &
OTHER PRODUCTS
• ***ELECTRICITY & RADIANT ENERGY---INHIBIT
BACTERIAL GROWTH

18. • **CHEMICALS---DESTROY & INHIBIT THE
GROWTH OF BACTERIA
• CHEMOTAXIS---RESPONSES TO CHEMICALS;
POSITIVE OR NEGATIVE RESPONSES
• **OSMOTIC PRESSURE----MOST BACTERIA
RESIST SMALL CHANGES IN OSMOTIOC
PRESSURE

19. • ** BACTERIA CAN BE KILLED BY HIGH
CONCENTRATIONS OF SALT OR SUGAR THUS
EMPLOYED IN FOOD PRESERVATION
• ***OSMOPHILES----PREFER HIGH SALT
CONCENTRATIONS; CLASSIFIED AS
HALOPHILES OR SALT LOVERS WHERE THEY
CAN TOLERATE HIGH CONCETRATIONS OF
SALT

20. BACTERIAL INTER- RELATIONS
• SYMBIOSIS---BACTERIA GROWING WELL
TOGETHER; BOTH PARTIES ARE BENEFITTED
• 1. SYNGERGISTIC RELATIONSHIP BETWEEN
STAPHYLOCOCCI & THE INFLUENZA BACILLI
• 2. LEGUMES & THE NITROGEN-FIXING
BACTERIA---NITROSOMONAS/ NITROBACTER
• ***ANTAGONISM---PRESENCE OF 1
ORGNAISM INHIBITS THE OTHER DUE TO
SUBSTANCES THAT ARE SECRETED

21. MAJOR METABOLIC ACTIVITIES
• ENZYMES----PLAY AN IMPT ROLE IN THE
METABOLLIC ACTIVITIES OF BACTERIA
• 2,000-3,000 ENZYMES IN THE BACTERIAL CELL
UNDER THE CONTROL OF THE DNA
APPARATUS
• CHEMOSYNTHESIS---PROCESSING OF ENERGY
FROM THE CHEMICAL ALTERATION OF
SUBSTANCES AT HAND

22. • 1. BACTERIAL DIGESTION---MAKES USE OF
HYDROLASES (ENZYMES) & HYDROLYSIS---
PROCESS INVOLVING THE ADDITION OF
WATER
• 2. ABSORPTION---VIA DIFFUSION & ACTIVE
TRANSPORT OF MOLECULES
• 3. OXIDATION---PREPARATION OF MOLECULES
FOR A POSSIBLE BONDING OR CHEMICAL
COMBINATION

23. • ---STARTS WITH PHOSPHORYLATION
• INVOLVES
OXIDASES/DEHYDROGENASES/COENZYMES
OF THE CYTOCHROME SYSTEM
• INVOLVES TRANSFER OF ELECTRONS
RESULTING IN AN OXIDIZED OR REDUCED
PRODUCT WHERE ENERGY IS LIBERATED OR
TRAPPED

24. CLASSES OF BIOLOGIC OXIDATION:
• A. AEROBIC---ULTIMATE HYDROGEN
ACCEPTOR IS MOLECULAR OXYGEN
• B. ANAEROBIC---HYDROGEN ACCEPTOR IS
INORGANIOC NITRATE, SULFATE OR
CARBONATE
• FERMENTATION---HYDROGEN ACCEPTOR IS
AN ORGANIC COMPOUND; USES ORGNANIC
COMPOUNDS BOTH AS DONORS & ELECTRON
ACCEPTORS

25. MEDICALLY RELATED ACTIVITIES:
• ***TOXIGENICITY---TOXIN PRODUCTION
• ***TOXICITY---POTENCY OF THE TOXINS
• A. EXOTOXINS---PROTEINS IN NATURE
• ------ANTIGENIC; PRODUCES ANTITOXIN
• -----SPECIFIC---CAUSES 1 DISEASE & NOTHING
ELSE
• ANATOXINS/ TOXOIDS---MODIFIED TOXINS THAT
CAN NO LONGER CAUSE DISEASE BUT CAN STILL
PRODUCE IMMUNITY TO THE DISEASE

26. • B. ENDOTOXINS---MADE UP OF COMPLEX
LIPOPOLYSACCHARIDES
• ---DO NOT PROMOTE ANTITOXIN FORMATION
• ---NON-SPECIFIC
• ---CANNOT BE CONVERTED INTO TOXOIDS
• EX. SALMONELLA TYPHI
• NEISSERIA MENINGITIDES

27. HARMFUL METABOLLIC PRODUCTS
• ---MAY NOT BE DIRECTLY TOXIC BUT RELATED
SIGNIFICANTLY TO DISEASE
• 1. HEMOLYSINS---CAUSE LYSIS OF THE RED
BLOOD CELLS
• 2 TYPES OF BACTERIAL HEMOLYSINS:
• A. FILTRABLE
• B. THOSE THAT ARE DEMONSTRATED ABOUT
THE BACTERIAL COLONY ON A CULTURE
MEDIUM CONTAINING RBCs

28. • & HEMOLYSINS ---- NAMED AFTER THE BACTERIA
THAT GIVES RISE TO THEM
• EX. STAPHYLOLYSIN
• STREPTOLYSINS
• 2. LEUKOCIDINS---DESTROY
POLYMORPHONUCLEAR NEUTROPHILIC
LEUKOCYTES
• ***FORMED BY PNEUMOCOCCI,STREPTOCOCCI &
STAPHYLOCOCCI

29. • 3. COAGULASE---ACCELERATE COAGULATION OF
BLOOD
• EX. STAPHYLOCOCCI
• COAGULASE TEST---USED TO DIFFERENTIATE
PATHOGENIC FROM NON-PATHOGENIC BACTERIA
• 4. BACTERIAL KINASES---ACT ON CERTAIN
COMPONENTS OF THE BLOOD TO LIQUIFY FIBRIN;
INTERFERE WITH BLOOD COAGULATION

30. • EX. STREPTOKINASE/FIBRINOLYSIS---
PRODUCED BY MANY HENOLYTIC
STREPTOCOCCI, STAPHYLOCOCCI & OTHER
BACTERIA
• ---USED TO DISSOLVE BLOOD CLOTS & TO
PREVENT THE FORMATION OF ADHESIONS
THAT WOULD BE LAID DOWN ON THE FIBRIN
PRECIPITATED IN THE BODY CAVITIES

31. • -5. HYALURONIDASE---MAKE TISSUES MORE
• PERMEABLE TO THE BACTERIA ELABORATING
IT
• EX. PNEUMOCOCCI & STREPTOCOCCI
• 6. BACTERIOCINS---BACTERIAL PROTEIN OR
POLYPEPTIDE SUSBTANCES PRODUCED BY
STRAINS OF A FAMILY OF MICROBES

32. • 7. COLICINS----PRODUCED BY THE FAMILY
ENTEROBACTERIACEAE; WILL ACT ON THE
BACTERIAL MEMBRANE
• OTHER EFFECTS:
• 1. PIGMENT PRODUCTION---IMPT. IN THE
IDENTIFICATION OF ORGANISMS BUT NOT
RELATED TO DISEASE PRODUCTION

33. • ***PRODUCED BY BOTH PARASITIC &
SAPROPHYTIC BACTERIA
• EX. STAPHYLOCOCCUS AUREUS---GOLD COLOR
• PSEUDOMONAS AERUGINOSA---PRODUCES
THE BLUE-GREEN PIGMENT
• HALOBACTERIUM HALOBIUM---PRODUCES
RED PIGMENT
• SERRATIA MARCESCENS---RED PIGMENT

34. • 2. HEAT PRODUCTION----RESULTS IN THE
HEATING OF DAMP HAY
• 3. LIGHT PRODUCTION
• EX. BIOLUMINESCENCE---EXHIBITED BY
BACTERIA THAT LIVE IN SALT WATER; EMITS
LIGHT AS THEY OPEN THEIR MOUTHS; LIGHT
PRODUCERS ARE GENERALLY NON-
PATHOGENIC

35. • 4. PRODUCTION OF ODORS---DUE TO
DECOMPOSITION OF THE MATERIAL WHERE
THE BACTERIA IS GROWING