Ch 18.1 Bacteria

1. Ch 18.1 Bacteria • one celled prokaryotes (“before nucleus”) • first life on earth and most numerous • divided into two kingdoms

2. 1. Eubacteria • live almost everywhere (soil, air, water, and inside others) • have cell wall of peptidoglycan • some have second cell wall

3. 2. Archaebacteria • have different membrane lipids and ribosome proteins • more like eukaryotes than eubacteria • may be ancestors of eukaryotes • live in harsh environments • thermoacidophiles • halophiles • methanogens

4. Identifying Prokaryotes • by shape - bacilli, cocci, spirilla (spirochete) • By arrangement - diplo, strepto and staphylo

5. by cell wall type- gram positive or gram negative, by way they move –flagella, spiraling, gliding or no movement

6. - by way they obtain energy • Autotrophs capture energy to make food -photoautotrophs called cyanobacteria - chemoautotrophs(break down hydrogen sulfide) • Heterotrophsmust eat to get energy and nutrients - saprobes decompose organic molecules (dead stuff)

7. -by the way they break down molecules in respiration • some need oxygen for respiration – obligate aerobes • some can only live in absence of oxygen – obligate anaerobes • some can live in both – facultative anaerobes

8. Benefits of bacteria 1. Most important role is ecological -breakdown and decomposition of organic matter (decay) - makes nutrients available for others - cleans the environment

9. Other Benefits of Bacteria 2. Nitrogen fixation - converts nitrogen in air, to a useable form for plants (in soil or in nodules on legumes) 3. Food production – cheese, butter, yogurt and pickled products 4. Drug and chemical production thru genetic engineer- ing (growth hormones, insulin, antibiotics) 5. Can digest small oil spills, remove poisons from water 4. Help digest food and production of vitamin K in digestive tract

10. Pathogens – disease causingagents • Examples : pneumonia, diptheria, typhoid, leprosy, strep and staph infection • harm organisms by: 1 direct attack (tuberculosis) 2. releasing harmful toxins (poisons) ie. salmonella and botulism, strep, diptheria

11. Protection against Bacteria: 1. barriers (skin, mucous membranes) 2. white blood cell attack 3. vaccine-weakened or killed bacteria that stimulate the body to produce antibodies 4. antibiotics -penicillin - discovered by Alex Fleming in 1929

12. Growth and Reproduction • Asexual reproduction – binary fission – produces identical daughter cells • Conjugation – genes are passed from one cell to another thru pili - new combinations of genes results in greater diversity • Endospores form in unfavorable conditions – protects DNA for years

13. Double Bonus: Bacteria Eat Pollution, Generate Electricity • Scientists have long studied bacteria that can clean up toxic waste by eating it. Other bacteria have been employed to produce electricity. • Now scientists have found a two-for-one deal in bacteria that will eat toxic chemicals 24/7 and make electricity to boot. • "The bacteria are capable of continuously generating electricity at levels that could be used to operate small electronic devices," says Charles Milliken of the Medical University of South Carolina, who conducted the research with colleague Harold May. "As long as the bacteria are fed fuel they are able to produce electricity 24 hours a day." • The new study involved Desulfitobacteria, already known for their ability to breakdown and detoxify some of the most problematic environmental pollutants, including PCBs and some chemical solvents. • "These bacteria are very diverse in their metabolic capabilities, including the food that they can consume. That means that these bacteria can convert a large number of different food sources into electricity," says Milliken. "The technology could be used to assist in the reclamation of wastewaters, thereby resulting in the removal of waste and generation of electricity." • The bacteria perform their useful tasks while in spore form, a dormant stage of growth that can handle extreme heat, radiation and lack of water -- all useful traits for an organism that might be employed in some of the worst manmade environments.

14. Related News • Talking Bacteria, and How to Shut Them Up • Waste Not: Energy from Garbage and Sewage • Jolted Bacteria Make Hydrogen from Human Waste • Bacteria Uses Sonar-Like Strategy to Probe Environment • Personal Nuclear Power: New Battery Lasts 12 Years • Scientists Make Bacteria Behave Like Computers

15. » Is Antibacterial Soap Really Necessary? » Bacteria Found Nearly 2 Miles Underground » New Approach Disarms Deadly Bacteria » Space Yogurt Made With Astro-Bacteria » Microbots Designed to Swim Like Bacteria » Intestinal Bacteria May Explain Obesity

16. Eureka! Bacteria Have the Midas Touch • » Bacteria & Fungi Ride Dust Across Oceans • » Starving Bacteria Cooperate to Make 'Superstrain' • » Picture Perfect Method to Detect Deadly Bacteria • » Bacteria vs. Bacteria: The New Fight Against Salmonella • » Bacteria in Yogurt Modified to Fight HIV Infection • » Bacteria Thrive in Hostile Human Bellies • » Bacteria Used as Photo Film