1. Chapter 5 The Microbial World Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. Learning Targets Today I will learn what a marine virus is Today I will learn what a marine virus is I will learn the difference between a lytic and a lysogenic cycle. I will learn the difference between a lytic and a lysogenic cycle. I will learn how viruses contribute to the overall nutrient content of the oceans. I will learn how viruses contribute to the overall nutrient content of the oceans. Today I will learn Today I will learn the difference between a prokaryote and a eukaryote Today I will learn the different metabolic activities of prokaryotes

3. Viruses Non-cellular infectious agents that have two basic characteristics: Non-cellular infectious agents that have two basic characteristics: –Not capable of reproduction without a host cell –Structure: Nucleic acid core- can be DNA or RNA Nucleic acid core- can be DNA or RNA Capsid (Protein coat)- consists of numerous protein subunits organized into rod-like or many sided shape. Protein coat also contains specific proteins that bind with receptors on host cells (great at mimicry!!) Many glycoprotein spikes extend from coat-these spikes mutate so frequently that our immune system cannot keep up. Capsid (Protein coat)- consists of numerous protein subunits organized into rod-like or many sided shape. Protein coat also contains specific proteins that bind with receptors on host cells (great at mimicry!!) Many glycoprotein spikes extend from coat-these spikes mutate so frequently that our immune system cannot keep up.

5. Viruses Notable Types of Viruses: Notable Types of Viruses: Retroviruses- store genetic information in the form of nucleic acid known as RNA Retroviruses- store genetic information in the form of nucleic acid known as RNA Lysogenic viruses – reproduce by inserting their DNA into the DNA of the host cell Lysogenic viruses – reproduce by inserting their DNA into the DNA of the host cell Bacteriophages – viruses that infect bacteria Bacteriophages – viruses that infect bacteria

6. Viruses Viruses in the Marine Community: Viruses in the Marine Community: –Common in marine waters –Can infect bacteria, plankton, fish, sea turtles and marine mammals –Lysis (bursting) of viral infected cells spills contents and releases large amounts of organic matter that can be utilized by other organisms (dissolved organic matter or DOM)

7. Prokaryotes Archea and Bacteria Archea and Bacteria Characteristics of Archean and Bacterial Cells: Characteristics of Archean and Bacterial Cells: –Prokaryotic - no nucleus –Single chromosome (normally circular) - some also with plasmids –Most with cell wall –Great metabolic diversity

8. Prokaryotes Archea – Archea – –Ancient organisms – fossils found that date back 3.8 billion years –Some live in very extreme environments –Variety of metabolic types –Widely distributed in the marine community –They can tolerate wide ranges in temperature, salinity and even desiccation (drying out) –Can be found in many areas including near hydrothermal vents and salt flats (two very extreme environments)

9. Prokaryotes Special Features of Bacteria: Special Features of Bacteria: A variety of shapes including spirals, spheres, rods and rings A variety of shapes including spirals, spheres, rods and rings Cell wall structure is semi-rigid, but permeable; most with cell wall Cell wall structure is semi-rigid, but permeable; most with cell wall Size is normally microscopic, but a few are large Size is normally microscopic, but a few are large Wide variety of metabolic types Wide variety of metabolic types Very abundant worldwide Very abundant worldwide

10. Prokaryotes Special Features of Bacteria: Special Features of Bacteria: –Bacteria in the marine community breaks down dead organic matter – this forms detritus, which are minute particles of organic matter now available as nutrition for other organisms –Cyanobacteria are a group of photosynthetic bacteria –Stromalites, massive calcareous mounds formed by cyanobacteria, have been found that are billion years old

12. Prokaryotes Metabolic diversity: Metabolic diversity: Photosynthesis – derive energy from light Photosynthesis – derive energy from light Chemosynthetic – derive energy from chemical compounds Chemosynthetic – derive energy from chemical compounds Heterotrophs – derive energy from organic matter by respiration Heterotrophs – derive energy from organic matter by respiration

13. http://www.divediscover.whoi.edu/ vents/light.html http://www.divediscover.whoi.edu/ vents/light.html

14. Formative Assessment Define a virus Define a virus What is the major difference between a Retrovirus, a Lysogenic virus, and a Bacteriophage? What is the major difference between a Retrovirus, a Lysogenic virus, and a Bacteriophage? What are the major differences between Photosynthesis, Chemosynthesis, and respiration? What are the major differences between Photosynthesis, Chemosynthesis, and respiration?

15. Learning Targets Today I will be able to recognize and describe diatoms, dinoflagellates, protists, protozoans, and fungi

16. Diatoms Diatoms: Diatoms: –Photosynthetic –Yellow-brown color photosynthetic pigments, chlorophyll A & C and carotenoids photosynthetic pigments, chlorophyll A & C and carotenoids –Shell of silica called a frustule –Most important primary producer on Earth –Mostly solitary and unicellular –Some can form colonies

18. Diatoms Diatoms Diatoms –Around half of the 12,000 known species are marine –Most are planktonic –Store excess energy as an oil which also aids in buoyancy –Tiny pores in shell used for gas/nutrient exchange –Some produce a toxin, known as domoic acid, that can accumulate in the tissues or organisms that eat diatoms such as shellfish and small fish –Larger organisms that eat these shellfish or small fish can become ill or die from this accumulated toxin

19. Diatoms Diatoms Diatoms –Mainly reproduce by cellular division (a form of asexual reproduction) –In this type of reproduction, the cell divides and each result cell gets one-half of the frustule. –This cell now must secrete the other half of the frustule (smaller piece) –Due to this, diatoms get smaller each time they reproduce –To restore normal size, they must either sexual reproduce or cast off the frustule and secrete an entire new frustule

21. Dinoflagellates Dinoflagellates Dinoflagellates –Most species live in marine environment –Mostly photosynthetic, some can ingest particles –Each species has unique shape reinforced by plates of cellulose –Two flagella in grooves on body that produce motion –Also reproduce by cellular division –Some are bioluminescent (read “Bay of Fire” on pg. 96)

24. Dinoflagellates Dinoflagellates Dinoflagellates –Zooxanthellae are important dinoflagellates that live in a symbiotic relationship with corals, sea anemones and other organisms (many of these host organisms have little or no growth without their symbiotic partner)

25. Algal Blooms Diatoms and dinoflagellates can go through periods of rapid growth known as “blooms” Diatoms and dinoflagellates can go through periods of rapid growth known as “blooms” This is a result of high levels of nutrients in the water This is a result of high levels of nutrients in the water These blooms can be harmful to marine organisms and even people at times These blooms can be harmful to marine organisms and even people at times

26. Dinoflagellates Dinoflagellates –A few species lack chloroplasts and live as parasites in marine organisms –Some species can reproduce in larger numbers and produce “Red Tide” (read “Red Tides and Harmful Algal Blooms, pg. 338) –Pfiesteria is a dinoflagellate that produces very serious toxins that can cause massive fish kills, harm shellfish and impair the nervous system in humans. –Pfiesteria was discovered near the Outer Banks in North Carolina

27. Protists A few more species of phytosynthetic plankton: A few more species of phytosynthetic plankton: –Silicoflagellates Star-shaped internal skeleton of silica Star-shaped internal skeleton of silica Two flagella of varying lengths Two flagella of varying lengths –Coccolithophores Ornate shells of calcium carbonate Ornate shells of calcium carbonate

30. Protozoa Foraminiferans (forams) Foraminiferans (forams) –Exclusively found in marine community –Found on sandy or rocky bottoms –Shells of calcium carbonate –Can be important contributors of calcareous material on coral reefs or sandy beaches –Pseudopods (false feet) extend through pores in the shell where they are used to capture minute food particles such as phytoplankton

32. Protozoa Radiolarians Radiolarians –Planktonic, mostly microscopic, although a few can reach large sizes –Shell of silica –Like forams, they use pseudopods that extend through pores in the shell where they are used to capture minute food particles such as phytoplankton

34. Protozoa Ciliates Ciliates –Cilia present for locomotion –Most live as solitary cells –Some build shells made of organic debris –May live on hard substrate –Some are planktonic

36. Fungi Most of the 1500 species of marine fungi are microscopic Most of the 1500 species of marine fungi are microscopic

37. Fungi Like bacteria, many fungus break down dead organic matter into detritus Like bacteria, many fungus break down dead organic matter into detritus Some fungus live in symbiosis with cyanobacteria, these are known as lichens Some fungus live in symbiosis with cyanobacteria, these are known as lichens Marine lichens often live in wave-splashed areas of rocky shorelines and other hard substrate Marine lichens often live in wave-splashed areas of rocky shorelines and other hard substrate

38. Most Important Characteristics of Marine Microbes

39. Formative assessment Formative assessment Card match Card match