Diversity of Prokaryotes

1. Diversity of Prokaryotes Kathy Huschle Northland Community and Technical College

2. Metabolic Diversity • the use of different compounds to obtain energy required for the organism, allow for occupation in diverse habitats, creating diversity among microorganisms ocean hot springs mud

3. Review of Terms • chemotroph • transfer energy from one compound to another through the process of oxidation-reduction reactions • phototroph • uses light as its energy source • chemoorganotrophs • obtain energy from organic sources • chemolithotrophs • obtain energy from inorganic sources • aerobic • respiration in the presence of oxygen • anaerobic • respiration in the absence of oxygen

4. Metabolic Diversity • anaerobic chemotrophs • habitat includes any that is lacking in oxygen • mud or tightly packed soil • some aquatic environments where high levels of nutrients exist (generally polluted lakes) • increase in nutrients allows for rapid multiplication of oxygen consuming microbes, thus precluding oxygen available for other organisms, such as fish

5. Metabolic Diversity • the human (and other animals) gut is about 99% anaerobic microorganisms • this environment is created by the presence of aerobic organisms which quickly deplete the available oxygen

6. Metabolic Diversity • anaerobic chemolithotrophs • most are members of the Archaea domain • methanogens • generate energy by oxidizing hydrogen • byproduct of this process generates methane gas Methanococcus jannischii

7. Metabolic Diversity • anaerobic chemoorganotrophs • oxidize organic compounds like glucose to obtain energy • sulfur/sulfate-reducing bacteria • use sulfur as energy source • by product is smelly hydrogen sulfide gas • generally live in rich organic mud Desulfovibrio variabrilis

8. Metabolic Diversity • anaerobic chemoorganotrophs • obtain energy using fermentation • byproducts of gases and acids are very easily distinguished and can be used for identification • 2 significant bacteria • clostridiums • lactic acid bacteria Aeromonas hydrophila

9. Metabolic Diversity • Clostridium • gram positive rods capable of forming endospores • commonly found in the soil • Clostridiums of concern • C. tetani • C. botulinum • C. perfringens C. perfringens C. tetani C. botulinum

10. Clostridium tetani • causative agent for tetanus (lockjaw) • spores can be acquired from any type of skin trauma with an infected device • spores than germinate in an anaerobic environment forming active C. tetani cells

11. Clostridium tetani • at the tissue level • an exotoxin is released from the C.tetani cells causing nervous system irregularities resulting in uncontrollable muscle contractions • immunization is available to prevent tetanus

12. Clostridium botulinum • causative agent for botulism • most potent toxin in existence • 1 gm of C. botulinum can kill 225 million people • disease results from ingesting toxin contaminated food • does not result in any noticeable changes in food taste or appearance • organisms generally arise from processing food, most commonly home processiong spore cell

13. Clostridium botulinum • damaged cans should be destroyed • the organism may enter through holes in the cans • bulging cans should be destroyed since they may indicate the production of gas

14. Clostridium botulinum No more discounted canned goods at the grocery store! Even a can with a small dent has the possibility of being contaminated with C. botulinum.

15. Clostridium perfringens • as C. perfringens grow they ferment carbohydrates producing a gas byproduct • infections of C. perfringens can also lead to systemic infections causing severe diarrhea • C. perfringens can also cause food poisoning C. perfringens on sheep blood agar

16. Clostridium perfringens • causative agent for gas gangrene • exotoxin causes necrosis of the tissue • damaged tissue enhances the further growth of more microorganisms • C. perfringens cannot grow in healthy tissue

17. Metabolic Diversity • Lactic Acid bacteria • Gram + • produce lactic acid as the end product of fermentation • significant genus include • Streptococcus • Lactobacillus Lactobacillus Streptococcus

18. Streptococcus • cocci, that generally are found in chains • produce exotoxins that destroy • phagocytic cells • host connective tissue • fibrin: a substance that is essential for the formation of blood clots S. pneumoniae in sputum S. pyrogenes S. mutans

19. Streptococcus • S. pyogenes • causative agent for strep throat, impetigo and scarlet fever

20. Streptococcus • S. pneumoniae • causativie agent for pneumonia, meningitis, otitis media S. pneumoniae onblood agar S. pneumoniae in lung tissue

21. Streptococcus • S. mutans • causative agent for dental caries (tooth decay) • bacteria lives only on the teeth, cannot colonize the mouth without teeth Colonies of S. mutans on MSB agar Tooth decay

22. Lactobacillus • Gram +, rod shaped, single or loosely associated chains • ferment glucose into lactose • a common application is in the dairy industry where there are involved in the production of fermented milk products such as cheese and yogurt Lactobacillus on Rogosa agar

23. Lactobacillus • Lactobacillus are also found in the normal flora of the vagina • they create an acid environment as a result of fermentation • that acidic environment inhibits the growth of many bacterial species and assists the vagina in preventing infection Lactobacillus infection

24. Metabolic Diversity • anoxygenic phototrophs • believed to be among the first organisms inhabiting our planet • photosynthetic process produces carbohydrates but does not generate O2 The purple sulfur bacteriumis Chromatium, the green sulfur bacterium is Chlorobium.

25. Metabolic Diversity • anoxygenic phototrophs • found in aquatic habitats: bogs, upper layers of mud • purple bacteria • green bacteria Purple non-sulfur bacteria Green sulfur bacteria Purple sulfur bacteria

26. Anoxygenic Phototrophs:purple bacteria • purple sulfur bacteria • Gram – bacteria • appear red, orange or purple in color due to pigments for light harvesting • photosynthetic microorganisms, generally found in sulfur rich habitats Purple sulfur bacteria in a microbial mat in Yellowstone Filter on agar

27. Anoxygenic Phototrophs:purple bacteria • purple sulfur bacteria • generally use hydrogen sulfate as energy source • capable of moving up and down in a water column to their preferred water level Purple sulfur bacteria surrounding diatoms

28. Anoxygenic Phototrophs:purple bacteria • purple non-sulfur bacteria • use organic material to acquire energy • extremely versatile organisms, capable of • adapting metabolism similar to purple sulfur bacteria • can grow aerobically in the absence of light Family Rhodospirillaceae Colonies on agar

29. Anoxygenic Phototrophs:green bacteria • green bacteria are Gram – • usually green or brown in color • pigments are found in chlorosomes • green sulfur bacteria • green non-sulfur bacteria Green non-sulfur bacteria Chloroflexus

30. Metabolic Diversity • oxgenic phototrophs • cyanobacteria- earliest known oxygen producer • believed that the chloroplasts found in plants and algae originated from cyanobacteria 6CO2 + 6H2O C6H12O6 + 6O2 • cyanobacteria chemical formula for photosynthesis

31. Oxgenic Phototrophs • cyanobacteria • occupies the role of a primary producer in an ecosystem • diverse genus that can be found in many different environments • freshwater • marine habitat • soil • rock surface Cyanobacteria in hot spring at Yellowstone National Park

32. Metabolic Diversity • aerobic chemolithotrophs • obtain energy by oxidizing substances like sulfur, ammonia, nitrate and hydrogen gas Thiobacillus

33. Metabolic Diversity • aerobic chemoorganotrophs • obtain energy by oxidizing organic compounds • this group contains many medically significant species of bacteria • obligate aerobes include genus • Micrococcus • Mycobacterium • Pseudomonas Micrococcus Mycobacterium Pseudomonas

34. Aerobic Chemoorganotrophs • faculative anaerobes include genus • Corynebacterium • Enterobacteriaceae Corynebacterium Enterobacteriaceae

35. Micrococcus • Gram + cocci • habitat includes soil, dust, inanimate objects, and skin • are airborne bacteria and can easily contaminate lab media Micrococcus lusteus colony

36. Mycobacterium • Gram +, though they stain poorly with a Gram stain • require an acid fast staining procedure due to a waxy lipid in the cell wall of Mycobacterium • are found throughout nature • are the causative agent for tuberculosis and leprosy Mycobacterium Tuberculosis tuber

37. Mycobacterium • M. tuberculosis • causative agent of tuberculosis Colonies on agar M. tuberculosis Tuberculosis is the leading cause of death in the world from a single infectious disease.  Mycobacterium tuberculosis infects 1.7 billion people/year which is equal to 33% of the entire world population. the bacterium is responsible for over 3 million deaths/year.

38. Mycobacterium • M. leprae • causative agent for leprosy In the US, M. leprae is the cause of about 6,000 new cases each year.  Most cases are seen in the southern states.  In total, there are about 5 to 10 million cases worldwide, but mostly in tropical and sub-tropical areas such as Central Africa and Southeastern Asia

39. Pseudomonas • Gram – rods • widespread, generally found in soil and water • most are harmless • medically significant species is • Pseudomonas aeruginosa • Pseudomonas aeruginosa

40. Pseudomonas aeruginosa • opportunistic pathogen • generally infects those who are in a weakened state such as illness, surgical patients, old people • fairly resistant to disinfectants and antimicrobial medications abscess caused by P. aeruginosa infection Pseudomonas aeruginosa

41. Facultative Anaerobes • Corynebacterium • Gram + rods • commonly found in soil and plant surfaces • C. diptheriae is the causative agent for diptheria C. diptheriaeon chocolate agar C. diptheriae

42. C. diptheriae • successfully controlled by immunization Pharnygeal infection, causative agent: C. diptheriae diphtheria cases in the US

43. Enterobacteriaceae Enterobacter • Gram - rods • often called enterics or enterobacteria • “gut” organisms • significant genus include • Enterobacter • Klebsiella • Escheria • Shigella • Salmonella • Yersinia Escheria Shigella Salmonella Klebsiella Yersinia

44. Enterobacter • widely distributed in humans, animals, water, sewage and soil • can cause urinary tract infections and hospital-acquired infections Enterobacter cloacae growing on XLD Agar

45. Klebsiella • commonly found in soil or water • can cause a serious form of pneumonia in humans Pneumonia caused by K. pneumoniae infection lung tissue Klebsiella pneumoniae growing on XLD Agar Characteristic bulging

46. Escheria • one of the most common inhabitants of the human intestinal tract • food digestion: produces vitamin K from undigested material • its presence in water or food is an indication of fecal contamination • generally is harmless but: • can cause urinary tract infections • strain E. coli 0157:H7 can cause serious food poisoning E. coli

47. Escheria Hemorrhagic infection caused by Escheria Click icon to view E. coli infection Click on each of the three parts

48. Shigella • found only in humans • can cause life-threatening dysentary • 2nd only to Escheria in causing “travelers diarrhea” Shigella

49. Salmonella • almost all members of this genus are pathogenic • bacterial food poisoning • transmission through uncooked meat and eggs • widespread presence in poultry products • up to 65% of poultry products contain the pathogen

50. Salmonella Click on icon to view animation. Click on the parts to continue.