Microbes and Producers Ch. 5 and 6

Viruses Considered to be non-living Not made of cells Contain genetic info (DNA or RNA) within a capsid (protein coat) Need a host cell to reproduce, sometimes destroying the host in the process Bacteriophages: viruses that target bacteria

Viral Infection

Viruses and DOM The bursting of cells can contribute to the dissolved organic matter (DOM) which can be a food source for bacteria and small zooplankton

Domains of Life The three domains which include all life are: Eubacteria Archaea Eukarya

Phylogeny

Eukaryotes vs. Prokaryotes

Eukaryotes vs. Prokaryotes

Domain: Eubacteria Eubacteria (Common Bacteria) Bacterial functions Prokaryotes: simple, single-celled, no nucleus Bacterial functions Decay: breaking down wastes and decomposing dead matter into inorganic nutrients; oil-eaters Photosynthesis: using sunlight to produce sugars

Domain: Eubacteria Types of marine eubacteria include: Cyanobacteria (blue-green bacteria) enriched Earth’s atmosphere with O2 Contain pigments: Phycocyanin-blue pigment Phycoerythrin-reddish pigment (the “red” in Red Tides) Purple and Green Bacteria Photosynthesize, but do not produce O2

Cyanobacteria Chains of blue-green Cyanobacteria

Bacterial Photosynthesis

Living Tropical Stromatolites Some of the oldest fossils found (~3 billion years old!) are of stromatolites, calcareous deposits made by cyanobacteria.

Domains of Life Archaea Single-celled prokaryotes, like eubacteria, but genetically similar to eukaryotes. Many are “Extremophiles” Live in extreme environments (hot, cold, high/low pH, high saline, high pressure)

Metabolism Autotrophs: make their own food Photosynthetic: use sunlight, carbon dioxide and water to make sugars Chemosythetic: use chemicals (hydrogen sulfide, ammonium, nitrite, or iron) and oxygen to make carbohydrates

Metabolism Heterotrophs: consume organic matter for energy by performing respiration Aerobic: use oxygen for respiration Anaerobic: do not use oxygen for respiration, they may not even grow in its presence May use sulfate instead of O2, causing a rotten egg smell that you could find in mud flats

Nitrogen Fixation Many bacteria, like cyanobacteria, are nitrogen fixers. They change atmospheric nitrogen into nitrates that can then be used as a nutrient by producers, like phytoplankton.

Nitrogen Fixation

Cycling of nutrients and Matter

Bacterial symbiosis Many bacteria have evolved symbiotic relationships with a variety of marine organisms Chemosynthetic bacteria live within tube worms and clams Some bacteria create toxins that are used by other marine organisms (Pufferfish tetrodotoxin) Some deep-sea or nocturnal animals host helpful bioluminescent bacteria photophores CLICK ME!

Bacterial Symbiosis Bioluminescence Pufferfish Giant tube worms

Domain Eukarya: Protists Protists are a diverse kingdom of organisms that may share similarities with members of the other kingdoms. Due to these similarities, we may classify them as: Plant-like Animal like Fungus-like

Plankton Phytoplankton Zooplankton Plant-like Animal-like Perform photosynthesis Eat food Producers Consumers Autotrophs Heterotrophs Ex. Diatoms Ex. Protozoans, Copepods, etc

Domain Eukarya Eukarya includes all organisms with eukaryotic cells Examples: plants animals fungi algae single-celled animal-like protozoa

Plant-like Protists Algae A green alga with flagella Performs photosynthesis in chloroplasts May have green, red, or brown (kelp) or pigments Lack true leaves, stems, roots, and flowers Maybe be able to swim with flagella A green alga with flagella

Plant-like Protists Diatoms Perform photosynthesis using golden-brown chloroplasts Have glassy shells called frustules made of silica Produce much of the oxygen in our atmosphere Diatoms make thick deposits of biogenous sediment Siliceous ooze Diatomaceous earth: used by humans in filters, as insulators, and as abrasives in toothpaste

Diatoms in Diverse Shapes

Plant-like Protists Dinoflagellates Most perform photosynthesis, but some also eat! Important primary producers in warm waters Maybe red, brown, yellow or other shades Account for about half of all Red Tides Many are bioluminescent (sea glow) Possess two flagella (tails) for locomotion Zooxanthellae have symbiotic relationships with many organisms and help form coral skeletons! Toxic Pfiesteria blooms can cause sores on fish and massive fish kills

A dinoflagellate with wrapped and trailing flagella

Fish kill due to Pfisteria bloom

Red Tide A brief video on a red tide off Florida’s coast.

Bioluminescent Dinoflagellates

Animal-like Protists Protozoans Foraminiferans Radiolarians Ciliates Single-celled heterotrophs Zooplankton Primary Consumers Very diverse, with an estimated 50,000 species Foraminiferans Radiolarians Ciliates

Animal-like Protists Foraminiferans Feed on diatoms using retractable pseudopodia Have shells made of calcium carbonate Become calcareous ooze when they die Can eventually form limestone and chalk beds

Foraminiferans Red Foraminifera skeletons form pink sands on the beaches of Bermuda.

Animal-like Protists Radiolarians Like Foraminiferans, use pseudopodia to capture food Have spherical spiny shells made of silica Make lots of sediment in deep waters because silica doesn’t easily dissolve

Animal-like Protists Ciliates Have lots of hair-like appendages called cilia. Usually found on the seafloor or attached to unusual places Paramecium

Animal-like Protists Ciliates Tintinnids are a type of ciliate that builds its own vase-like case out of sand, called a lorica, to help it float

Domain Eukarya: Fungi Eukaryotic Most are multicellular Have cell walls made of chitin Function as important decomposers May cause disease Live symbiotically with green algae or cyanobacteria to form lichens Lichens on tree bark

Check out this vid! Crash Course Biology Old & Odd: Archaea, Bacteria & Protists