1. The Eukaryotes: Fungi, Algae, Protozoa, and Helminths Part 2
Chapter 12
The Eukaryotes: Fungi, Algae, Protozoa, and Helminths
Part 2

2. Economic Effects of Fungi
Used in biotechnology, biological pest controls vs. undesirable effects
Gypsy moth control
Entomorphaga
Ceratocystis ulm (Dutch elm disease)
Taxol production
Taxomyces
Cryphonectria parasitica (chestnut blight)
Cellulose used for juices and fabric
Trichoderma
Food spoilage
Negative Effects
Bread, wine, beer
Saccharomyces
Positive Effects
Fungi

3. Lichens
Mutualistic combination of an alga (or cyanobacterium) & fungus
Classified according to the fungal partner (most often an ascomycete)
Mutualism: a type of symbiosis in which both organisms or populations are benefited
Alga produces and secretes carbohydrates (via photosynthesis), fungus provides holdfast (enclose alga)
Some of the slowest growing organisms on Earth

4. Lichens
Figure 12.10

5. Lichens
Often the first life forms to colonize newly exposed soil or rock
Colonize habitats that are unsuitable for either the alga or the fungus alone
Grouped into 3 morphologic categories
Crustose, foliose, and fruiticose
Used as dyes for clothing, an antimicrobial agent, the dye in litmus paper; cause allergic contact dermatitis

6. Algae Unicellular, filamentous, or multicellular
Mostly aquatic (in cool temperate waters); some found in soil or on trees
Eukaryotic photoautotrophs (lack tissues)
Oxygenic photosynthesis
Chlorophyll a and accessory pigments
Absorb nutrients from water
Identification by microscopic examination

7. Algae
Classification by rRNA sequences, structures, pigments, and other qualities
Reproduce asexually (fragmentation and cell division) and some can reproduce sexually (triggered by environmental condition)
Selected Phyla of Algae
Brown algae (kelp), red algae, green algae, diatoms, dinoflagellates, and water molds

8. Figure 12.11a

9. Phaeophyta Brown algae (kelp) Multicellular; macroscopic
Cellulose + Alginic acid cell walls
Chlorophyll a and c, xanthophylls
Store carbohydrates
Harvested for algin
Figure 12.11b

10. Rhodophyta Red algae Grow at deeper depth in ocean
Cellulose cell walls
Most multicellular
Chlorophyll a and d, phycobiliproteins
Store glucose polymer
Harvested for agar and carrageenan
Figure 12.11c

11. Chlorophyta Green algae Cellulose cell walls
Unicellular or multicellular; most are microscopic
Chlorophyll a and b
Store glucose polymer (starch)
Gave rise to terrestrial plants
Figure 12.12a

12. Bacillariophyta Diatoms Pectin and silica cell walls
Unicellular or filamentous algae
Chlorophyll a and c, carotene, xanthophylls
Store oil
Fossilized diatoms formed oil
Produce a neurotoxin (domoic acid)
Figure 12.13

13. Dinoflagellata Dinoflagellates Cellulose in plasma membrane
Unicellular; collectively called plankton
Chlorophyll a and c, carotene, xanthins
Store starch
Cause red tide (Alexandrium)
Neurotoxins cause paralytic shellfish poisoning & ciguatera
Figure 12.14

14. Oomycota Water molds Cellulose cell walls Multicellular
Chemoheterotrophic
Produce zoospores
Decomposers and plant parasites
Phytophthora infestans responsible for Irish potato blight
P. cinnamomi infects Eucalyptus
P. ramorum causes sudden oak death
Figure 12.15

15. Roles of Algae in Nature
Important part of aquatic food chain (fix CO2 into organic molecules that can be consumed by chemoheterotrophs) = primary producer
Primary producer: an autotrophic organism, either chemotroph or phototroph, that converts CO2 into organic compounds
Estimated that 80% of the Earth’s O2 is produced by planktonic algae

16. Roles of Algae in Nature
Seasonal red tide (blooms of dinoflagellates) and algal blooms
Much of world’s petroleum formed from fossil remains of diatoms and other planktonic organisms
Symbiotic relationship between unicellular algae and animals e.g. giant clam

17. Protozoa Unicellular and mostly aerobic Eukaryotic chemoheterotroph
Inhabit water and soil; some are part of the normal microbiota of animals
Vegetative form is a trophozoite (feeding and growing stage)
Trophozoite feeds upon bacteria and small particulate nutrients
Asexual reproduction by fission, budding, or schizogony (multiple fissions)

18. Protozoa
Sexual reproduction by conjugation (protozoan) e.g. Paramecium
Some produce cysts
Allows organisms to survive under adverse condition or outside a host
Oocyst: reproductive structure in which new cells are produced asexually
Figure 12.16

19. Protozoa Some have a protective covering (pellicle)
Ciliates take in food by waving their cilia toward a mouth like opening (cytostome)
Amoebas engulf food by extending pseudopods around it and phagocytize it
Digestion occurs in membrane-enclosed vacuoles
Waste eliminated through plasma membrane or through anal pore

20. Archaezoa No mitochondria Multiple flagella Giardia lamblia
Trichomonas vaginalis (no cyst stage)
Figure 12.17b-d

21. Microspora No mitochondria Nonmotile due to lack of microtubules
Obligate intracellular parasites
Cause of a number of human diseases, esp.. in AIDS patients
Nosema

22. Rhizopoda (amoebas) Move by pseudopods Entamoeba Acanthamoeba
Figure 12.18a

23. Apicomplexa Nonmotile in their mature form Intracellular parasites
Characterized by the presence of a complex of special organelles at the tips of their cells
Complex life cycles
definitive host (harbors sexually mature adult) and intermediate host (harbors the larval or asexual stage)
Plasmodium, Babesia, Cryptosporidium, & Cyclospora

24. Ciliophora (ciliates)
Move by cilia
Complex cells
Balantidium coli is the only human parasite
Figure 12.20

25. Euglenozoa Move by flagella Lack sexual reproduction Photoautotrophs
Euglenoids (pellicle)
Chemoheterotrophs
Naegleria
Flagellated and amoeboid forms, meningoencephalitis
Trypanosoma
Undulating membrane, transmitted by vectors
Leishmania
Flagellated form in sand fly vector, ovoid form in vertebrate host

26. Euglenozoa
Figure 12.21

27. Slime Molds Have fungal and amoebal characteristics
Cellular slime molds
(Fig )
Resemble amoebas, ingest fungi & bacteria by phagocytosis
Cells aggregate into stalked fruiting body.
Some cells become spores
Plasmodial slime molds (Fig )
Multinucleated large cells (protoplasm)
Cytoplasm separates into stalked sporangia
Nuclei undergo meiosis and form uninucleate haploid spores

28. Helminths Free-living worms and parasitic worms
Flatworms or roundworms
Eukaryotic multicellular animals
Adult can be monoecious (hermaphroditic) or diecious (two separate sexes)
Parasitic helminths
Lack a digestive system
Have reduced nervous system
Have reduced or completely lacking means of locomotion

29. Helminths Helminths (parasitic worms)
Complex reproductive system (definitive and intermediate hosts)
Helminths (parasitic worms)
Phylum: Platyhelminthes (flatworms)
Class: Trematodes (flukes) (Fig )
Class: Cestodes (tapeworms) (Fig )
Both classes absorb nutrients through nonliving outer covering (cuticle)
Cause disease in a wide varieties of animals
Phylum: Nematodes (roundworms)
Have a complete digestive system
Either eggs can be infective (pinworm) or larva can be infective (adult hookworms)

30. Trematodes (flukes)
Figure 12.25

31. Cestodes (tapeworms)
Figure 12.27

32. Nematodes: Eggs Infective for Humans
Figure 12.29

33. Nematodes: Larvae Infective for Humans
Figure 25.26

34. Arthropods as Vectors Kingdom: Animalia
Phylum: Arthropoda (segmented bodies, exoskeleton, jointed legs)
Insecta (6 legs)
Lice, fleas, mosquitoes, flied, bees
Arachnida (8 legs)
Mites, ticks, spiders
May transmit diseases (vectors)
Crustacea (4 antennae)
Crabs, crayfish
Figure 12.31, 32

35. Arthropods as Vectors
Vectors: arthropods that carry pathogenic microorganisms
Some parasites multiply in their vectors
Some vectors are a mechanical means of transport
a few arthropods suck blood and transmit microbial diseases while doing that
Elimination of vectorbone disease by eradication of the vectors

36. Chapter Review
Table 12.1

37. Chapter Review
Eukaryotic microorganisms: fungi, lichens, algae, protozoa, slime molds, and helminths
I. Fungi
Mycology: the study of fungi
Eukaryotic (yeast, molds, mushrooms, etc.)
Aerobic to facultative anaerobic
Chemoheterotrophic
Few are plant and human pathogens

38. Fungi Usually grow better in acidic environment (about pH = 5)
Require less nitrogen for growth
More resistant to osmotic pressure (high salt or sugar concentration)
Can grow on a very low moisture surface
Capable of metabolizing complex carbohydrates

39. Fungi
Most decompose organic matter (dead plant matter) to inorganic molecules
Recycle vital elements
Absorb nutrients instead of ingestion
Molds and fleshy fungi
Multicellular; aerobic
In a clinical lab, identified by 1) colony morphoogy, 2) type of phyphae (septate or coenocytic), and 3) type of asexual spores formed (at the tip of aerial hyphae)

40. Fungi
For taxonomy (classification), type of sexual spores are used
Yeasts
Unicellular; facultative anaerobe
Fermentation used in brewing, wine-making, and baking
Yeast identification in a clinical laboratory based on biochemical tests
Pathogenic dimorphic fungi have yeastlike form at 37 oC and moldlike form at 25oC

41. Fungi Fungal Diseases (Mycoses) Effects of Fungi
Tend to be chronic (long-lasting) due to slow growth and harder to treat since fungi are eukaryotes
Effects of Fungi
Used in biotechnology & biological pest controls; cause food spoilage
Used as foods; used to produce foods or drugs
Human pathogens (4 phyla): Zygomycota, Ascomycota, Basidiomycota, & Anamorphs (formerly Deuteromycota); plant pathogens

42. Lichens
Mutualistic combination of an alga (or cyano- bacterium) and fungus (most often an ascomycete)
Mutualism: a type of symbiosis in which both organisms or populations are benefited
Alga produces and secretes carbohydrates & fungus provides protection & holdfast
Classified according to their fungal partner
Used as dyes for clothing, dye in litmus paper, an antimicrobial agent; cause allergic contact dermatitis

43. Algae Unicellular, filamentous, or multicellular
Mostly aquatic (in cool temperate waters); some found in soil or on trees
Eukaryotic photoautotrophs (lack tissues); absorb nutrients from water
Oxygenic photosynthesis
Reproduce asexually (fragmentation and cell division) and some can reproduce sexually (triggered by environmental condition)

44. Algae
5 Phyla of Algae
Brown algae (kelp): macroscopic; in coastal waters; harvested for Algin (thickner for foods, rubber tires and hand lotion)
Red algae: grow at deeper depth in ocean; provide agar (used in microbial media) & carrageenan (a thickening ingredient in evaporated milk, ice cream, and pharmaceutical agents)
Green algae: believed to have given rise to terrestrial plants

45. Selected Phyla of Algae
Diatoms: unicellular or filamentous algae with complex cell walls (pectin & silica); store energy captured through photosynthesis as oil; some produce a neurotoxin (domoic acid)
Dinoflagellates: unicellular algae collectively called plankton (free-floating organisms); cause red tide; some produce neurotoxins (cause ciguatera and paralytic shellfish poisoning)
Water molds (oomycota): decomposers; form cottony masses on dead algae and animals (in fresh water); terrestrial oomycotes are plant parasites

46. Algae Roles of Algae in Nature
Important part of aquatic food chain; primary producers (fix CO2 into organic molecules that can be consumed by chemoheterotrophs)
Estimated that 80% of the Earth’s O2 is produced by planktonic algae
Much of world’s petroleum formed from fossil remains of diatoms and other planktonic organisms
Cause red tide
Symbiotic relationship between unicellular algae and animals (e.g. giant clam)

47. Protozoa Unicellular, eukaryotic chemoheterotrophic organisms
Inhabit water and soil; some are part of the normal microbiota of animals
Trophozoite: the feeding and growing stage; feeds upon bacteria and small particulate nutrients
Reproduce asexually by fission, budding, or schizogony (multiple fission)

48. Protozoa
Some reproduce sexually (e.g. Paramerium via protozoan conjugation)
Some produce a protective capsule (cyst) under certain adverse conditions
Encystment allows organisms to survive when food, moisture, or oxygen are lacking
Also allows a parasitic species to survive outside a host
oocyst: reproductive structure in which new cells are produce asexually

49. Protozoa Medically Important phyla
Archaezoa: lack mitochondria; many live as symbionts in the digestive tracts of animals; most have two or more flagella
Microspora: lack mitochondria & microtubules; obligate intracellular parasites; cause of a number of human diseases, esp. in AIDS patients
Rhizopoda (amoebas): pseudopods used for movement and engulfing food; some are pathogenic

50. Protozoa
Apicomplexa: non-motile, and obligate intracellular parasites in their mature forms; complex life cycle (definitive and intermediate hosts) e.g. Plasmodium (cause malaria)
Definitive host: harbors sexually mature adult parasite vs. Intermediate host: harbors the larval or asexual stage
Ciliophora (ciliates): have cilia that are moved in unison to propel the cell for movement and to bring food particles to the mouth; e.g. Balantidium coli (human pathogen)
Euglenozoa: have flagella and lack sexual reproduction

51. Slime Molds
Have fungal and amoebal characteristics (more closely related to amoeba)
Two phyla: cellular and plasmodial slime molds
Cellular slime molds: resemble amoebas; asexual reproduction only; large numbers of amoeboid cells aggregate to form a single structure that is enclosed in a slimy sheath (slug) (Fig )
Plasmodial slime molds: exists as a mass of protoplasm with many nuclei (multinucleated); sexual and asexual reproduction

52. Helminths Free-living worms and parasitic flatworms or roundworms
Multicellular eukaryotic animals
Parasitic helminths generally lack a digestive system (exception does exist); have reduced nervous system; have reduced or completely lacking means of locomotion; complex reproductive system; need definitive and intermediate hosts

53. Helminths Platyhelminthes (flatworms): flukes & tapeworms
Cause disease in a wide variets of animals
Absorb nutrients through nonliving outer covering (cuticle)
Use suckers for attachment
Humans can be definitive or intermediate hosts
Nematoda (roundworms)
Have a complete digestive system
Human infection: either egg is infective or larva is infective

54. Arthropods as Vectors
Arthropods: characterized by segmented bodies, hard external skeletons, and jointed legs; largest phylum in the animal kingdom
Representative classes of arthoropods
Arachnida: spiders, mites, ticks
Crustacea: crabs, crayfish
Insecta: bees, flies, lice
Vectorborne diseases is eliminated through eradication of the vectors

55. Arthropods as Vectors
Vectors: arthropods that carry pathogenic microorganisms
a few arthropods suck the blood of humans and other animals and can transmit microbial diseases while doing that
Some vectors are just a mechanical means of transportation e.g. houseflies
Some parasites multiply in their vectors & parasites accumulate in the vectors feces or saliva e.g. Lyme disease & West Nile virus, Plasmodium

56. Chapter Review
Know these terms: mycology, mycoses definitive host, intermediate host, vector (arthropod), and trophozoite.
Know the roles of fungi in nature and characteristics of fungi. Also know why fungal disease are harder to treat than bacterial diseases
Know characteristics of lichens.

57. Chapter Review Know the roles of algae in nature.
Know the function of cyst or encystment for protozoa. Know the characteristics of medically important protozoa.
Know the characteristics of slime molds.
Know the characteristics of parasitic helminths.