(bkgd)Comstock Images/PictureQuest Chapter 7 The Microbial World (bkgd)Comstock Images/PictureQuest  Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.

(bkgd)Comstock Images/PictureQuest Viruses Infectious particle not made up of a cell: Not capable of reproduction without a host cell Structure: Nucleic acid core – DNA or RNA Capsid (protein coat) – (bkgd)Comstock Images/PictureQuest  

(bkgd)Comstock Images/PictureQuest Viruses Common in the marine environment Can infect marine bacteria, plankton, invertebrates, fishes, sea turtles, and mammals ROLE: Lysis (bursting) of cells infected with viruses releases large amounts of dissolved organic matter (DOM) that can be used by other organisms (bkgd)Comstock Images/PictureQuest  

Tiny Plankton Drift with ocean currents & waves, the ”wanderers” Represents All kingdoms Types: Phytoplankton (photosynthetic algae) Zooplankton (small animals) Bacterioplankton (bacteria) Meroplankton (larval stage of benthic & nektonic animals) The 1st three are Holoplankton- ALWAYS plankton form

(bkgd)Comstock Images/PictureQuest Prokaryotes Archaea: Ancient organisms – fossils found that date 3.8 bya *1st bacteria on Earth They can tolerate wide ranges in temperature, salinity, and even desiccation (drying out). Extremophiles Can be found in many “hostile” areas including near hydrothermal vents Thermus aquaticus Deinococcus radiodurans (bkgd)Comstock Images/PictureQuest  

Prokaryotes Marine Bacteria: Break down dead organic matter forming detritus, making them available as food for other organisms Cyanobacteria -1st photosynthetic bacteria *gave us Oxygen on Earth Most abundant Picoplankton (very small) Single cell or colonial

(bkgd)Comstock Images/PictureQuest HOW THEY GET ENERGY Metabolic diversity of Archaea and Bacteria: Photosynthesis – derive energy from light Chemosynthesis – derive energy from chemical compounds Heterotrophs – derive energy from organic matter by means of respiration Nitrogen fixation – converting gaseous nitrogen (N2) into ammonium (NH4+) (bkgd)Comstock Images/PictureQuest  

7.3 Unicellular Algae (Phytoplankton) microscopic Single celled Color (green, brown, or red) results from photosynthetic pigments Examples: algae, diatoms, dinoflagellates (bkgd)Comstock Images/PictureQuest  

Phytoplankton Lives Matter ROLES (add to notes) They form an essential part of the marine food chain. Regulate the amount of carbon in the atmosphere.

(bkgd)Comstock Images/PictureQuest Diatoms (add to chart) Most efficient at photosynthesis has frustule - cell wall made of silica, a (glass-like shell) Produces oil (float) (bkgd)Comstock Images/PictureQuest  

(bkgd)Comstock Images/PictureQuest Marine Diatoms They store excess energy as an oil that also aids in buoyancy. Some produce a toxin, that can accumulate in the tissues or organisms that eat them such as shellfish and small fishes. Larger organisms that eat these shellfish or fishes can become ill or die from the accumulated toxin. (bkgd)Comstock Images/PictureQuest  

Why we like dead diatoms (Diatomaceous Earth) Used in filters Clarifying beer Temperature and sound insulators Mild abrasives in toothpaste (bkgd)Comstock Images/PictureQuest 

Dinoflagellates (add to chart) Two flagella for motion Migrate up during sunlight portion of day Migrate down at night for protection Cell wall Made of cellulose. Some are bioluminescent Rapidly reproduce (bkgd)Comstock Images/PictureQuest  

(bkgd)Comstock Images/PictureQuest Algal Blooms Diatoms and dinoflagellates can go through periods of rapid growth known as blooms. Causes red tides when conditions right (nutrients) Can create a Harmful algal bloom (HAB) Some produce strong neurotoxins which are harmful to marine animals (death) and humans (respiratory) (bkgd)Comstock Images/PictureQuest  

Marine Dinoflagellates (add to chart) Zooxanthellae are important dinoflagellates that live in a symbiotic relationship with reef corals, some sea anemones, and other organisms. Many of these host organisms can’t grow without zooxanthellae. (bkgd)Comstock Images/PictureQuest  

Other Unicellular Algae (add to chart) Coccolithophorids photosynthetic spherical cells calcium carbonate plates Fossils in chalk sediments White Cliffs of Dover Emiliania huxleyi This Photo by Unknown Author is licensed under CC BY-SA (bkgd)Comstock Images/PictureQuest  

(bkgd)Comstock Images/PictureQuest Fungi (add to chart) Cell wall cellulose or chitin Decomposers Cause diseases symbiotic with cyanobacteria to form lichens (bkgd)Comstock Images/PictureQuest  

Protozoans (add to chart) Foraminiferans : heterotrophs, animal-like Shells of calcium carbonate important contributors of calcareous material on coral reefs or sandy beaches. Have test (shell) made of CaCO3 Have Pseudopods (false feet) extend through pores in the shell where they capture food particles (bkgd)Comstock Images/PictureQuest  

(bkgd)Comstock Images/PictureQuest Protozoans Ciliates: Hair-like cilia for locomotion and feeding Most live as solitary cells. (bkgd)Comstock Images/PictureQuest  

Most Important Characteristics of Marine Microbes (bkgd)Comstock Images/PictureQuest