Types of Heterotrophic Nutrition

Methods of Feeding Saprophytic Nutrition Parasitism Predation feed on dead organic matter, get energy from it, and recycle it back into the environment. decomposers. Parasitism organism (parasite) feeds off of another (host) at the expense of the host. Predation - organism (predator) hunts, kills, and eats another organism (prey).  Scavenging feed on organisms killed by something else.

Kingdoms Archaebacteria & Eubacteria (Formerly Monera)

What are Bacteria? Bacteria are PROKARYOTES The smallest known living cells They are found everywhere!! Bacteria on head of a pin Starr, 317 Did you know? There are over 80 species of bacteria in your mouth! Bacteria in dental plaque microbeworld.org

Obtaining Energy Autotrophs (make energy) Photoautotrophs- capture energy from light Ex- cyabobacteria Chemoautotrophs- obtain energy from chemical reactions with inorganic molecules (ammonia, hydrogen sulfide, nitrites, sulfur, Iron) make glucose using energy from chemical compounds Ex. Ocean vent bacteria

Cyanobacteria bloom

Obtaining Energy cont… Heterotrophs- most bacteria obtain their energy from organic molecules These bacteria are often feeding in, on and around us… Some bacteria are photoheterotrophs Capture sunlight and digest organic molecules

Releasing Energy Bacteria can use both cell respiration and fermentation Many bacteria have different oxygen requirements: Obligate aerobes- must have oxygen for respiration Facultative anaerobes- can function with or without oxygen Obligate anaerobes- poisoned by oxygen (use fermentation)

Three basic shapes of Bacteria Spherical – coccus Rod – bacillus Coiled - spirillum Schraer, 633

Shapes of Bacteria

Coccus Spheres Cocci (plural) a variety of arrangements 11

Bacillus Cylindrical or rod-shape Bacilli (plural) Variations in cell arrangement Diplobacillus (paired) 12

Spirillium Spiral or “squiggle” shaped bacteria Vibrio Spirillum Spirochete 13

Simple Colonies Staphylo = clusters Strepto = chains Diplo = double Bacterial colony shapes have specific names that are used as A prefix that combines with the name of their shape. Staphylo = clusters Strepto = chains Staphylococcus wisc.edu Diplo = double Diplococcus cat.cc.md.us Streptobacillus

Many can MOVE Some have flagella - made of rope-like proteins, not microtubules. Some slide on a slimy secretion. Many can form dormant cells called endospores to survive harsh conditions. Salmonella www.iwate.jp Streptomyces spores

Bacterial Reproduction Bacterial cells reproduce asexually through fission which is the splitting of a cell into two new cells.

Bacterial Reproduction cont… Some bacteria utilize conjugation to exchange pieces of genetic information to increase variation *Not considered sexual reproduction- not complete exchange of DNA, no offspring made

Bacterial Cells Their Structure

Structure of a Bacterial Cell Cell Wall Outside membrane- maintains cell structure May have cell wall + capsule (second wall) Protects the cell Eubacteria-composed of peptidoglycan, a polymer of sugars and amino acids Plasma Membrane Controls what enters and exits, selectively permeable phospholipid bilayer surrounding cell contains proteins that play a role in transport of ions, nutrients, and wastes Flagella (not found in all bacteria) tail-like structure used for locomotion http://en.wikipedia.org/wki/Image:Average_prokaryote_cell-_en.svg

Structure of a Bacterial Cell Nucleoid region DNA is found in prokaryotes single double-stranded circular chromosome Contains all genetic information Plasmid (some bacteria) small circular chromosome carrying special genes may carry an antibiotic resistance gene Can be exchanged through conjugation Ribosomes site of protein synthesis (translation) http://en.wikipedia.org/wiki/Image:Average_prokaryote_cell-_en.svg Life Sciences-HHMI Outreach. Copyright 2008 President and Fellows of Harvard College.

Bacterial Structure Respiratory Enzymes Cytoplasm Use enzymes in the cytoplasm to undergo respiration Cytoplasm Fluid filling cell

Two Kingdoms of Bacteria Kingdom Archaebacteria - “Ancient”, most primitive earliest known form of life - Fluorescent micrograph of an archaeon microbeworld.org Kingdom Eubacteria - includes bacteria and cyanobacteria (blue-green)

Eubacteria

EUBACTERIA the “true” bacteria- more common

Cell Walls eubacterial cells have two different cell wall structures. A technique called gram staining can distinguish between: Gram-positive: cell wall containing mainly peptidoglycan- stains purple Gram-negative: bacterial cell has a second, outer layer of lipids and carbs- stains pink

Kingdom Eubacteria Photosynthetic – 2 groups 1) cyanobacteria (aerobes) Have chlorophyll a and phycocyanin (blue) Other colors, too Most live in fresh water Others live in salt water, soil and lichens Starr, 315 Nostoc Schraer, 637

- colors range from pink to black - photosynthesize without water More photosynthetics 2) green-sulfur and purple bacteria - anaerobic - colors range from pink to black - photosynthesize without water - make no oxygen - live in pond and sea mud

Cyanobacteria This is a group of bacteria that includes some that are single cells and some that are chains of cells. You may have seen them as "green slime" in your aquarium or in a pond. Cyanobacteria can do "modern photosynthesis", which is the kind that makes oxygen from water. All plants do this kind of photosynthesis and inherited the ability from the cyanobacteria.

Cyanobacteria were the first organisms on Earth to do modern photosynthesis and they made the first oxygen in the Earth's atmosphere.

Biologic Importance of Bacteria Essential to nutrient cycling Decomposers – in soil, inside animals Enterobacteria – live inside us, break down waste, make vitamins vitamin K is essential to blood clot formation. Process foods – cheese, yogurt etc.. Some MAKE antibiotics (streptomyacin)

Bacterial uses cont. 6) Help with sewage treatment Break down wastes 7) Can be utilized in genetic engineering, molecular research… Insert foreign genes into new organism Can be used to make specialized products like insulin 8) Indicate pollution levels Provide visual clue to presence of pollution

9) Nitrogen Fixation Still other Bacteria live on the roots of certain plants, converting atmospheric nitrogen into a usable form.

Some cause disease We call these “pathogens” Anthrax, as seen by Koch microbeworld.org But most are beneficial Bacteria ferment cheese Schraer, 641

Kingdom Archaebacteria Why a separate kingdom? Archae differ chemically from other bacteria. 1) cell wall - different amino acids and sugars. Eubacteria have peptidoglycan Archaebacteria have varied polysaccharides but not peptidoglycan. 2) unique membrane lipids 3) ribosomes 4) enzymes - - - - - - - - - - - - > 5) gene sequences . . . And MORE RNA polymerase

Archaebacteria Lack important carbohydrate found in cell walls Have different lipids in their cell membrane Different types of ribosomes Very different gene sequences Archaebacteria can live in extremely harsh environments They do not require oxygen and can live in extremely salty environments as well as extremely hot environments.

Archae are extremophiles Live in habitats like early earth Too harsh for most organisms 1) methanogens – decomposers, live in intestines, swamps & bogs sewage treatment 2) Halophiles – “love salt” Great Salt Lake, Dead Sea 3) Thermophiles – hot springs, geysers 4) Acidophiles – acidic environments Starr,635

Archaea, the “extremophiles” methanogens, thermophiles, halophiles

Nitrogen-fixing Chemosynthetic Eubacteria and Archaebacteria make glucose using energy from chemical compounds **Mostly archae Tube worms at ocean vent Fed by chemoautotrophs Starr, 745 Nitrogen-fixing Fix nitrogen in special cells called heterocysts Legume roots – nodules contain nitrogen-fixing bacteria Starr, 314