Microbio Exam 1 Week 1

Microbiology

the study of microscopic organisms

come from different environments/habitats

ubiquitous : found everywhere

extremophiles : can live in extreme environments

How do Microbes Benefit Us?

improve food safety

preserve food

add flavor

Microbial Ecology

study of the relationship between microorganisms and their environment

microorganisms are primarily responsible for converting carbon, nitrogen, oxygen, sulfur, and phosphorous into forms plants and animals can use

Martinus Beijerinck & Sergei Winogradsky

first to show how bacteria help recycle vital elements between the soil and the atmosphere

ex: algae cyanobacteria plants use co2 for photosynthesis to make carbohydrates- this co2 is fixed by bacteria and fungi who decompose into the environment

Bioremediation

microbial cleanup of oil, toxic chemicals, or other environmental pollutants

Bioenhancers

dumped ordinary nitrogen and phosphorus plant fertilizers, aka: a mixing of microbes to enhance a wanted trait or effect

ex: increase in oil-degrading bacteria

Bioaugmentation

genetically modified bacteria

specially adapted to metabolize petroleum products

Microorganisms and Agriculture

legumes (beans, peas) live in close association with bacteria and form nodules on their roots

these bacteria convert atmospheric nitrogen (N2) into ammonia (NH3)

used as a nitrogen source for plant growth

ruminants such as cattle and sheep graze on cellulose rich plants, bacteria in the rumen ferment the cellulose

Microorganisms and Industry

naturally occurring microorganisms are grown on a massive scale to make large amount of products at a low cost

ex: antibiotics, enzymes, and certain chemicals

Biotechnology

employs genetically engineered microorganisms to synthesize products of high value

ex: insulin or other human proteins but usually on a smaller scale

Microbiota

microbes present in and on the human body

complex carbohydrates (can represent 10-30% of food energy) are digested by gut microbiome

prevents growth of pathogens

Pathogens

microbes that cause disease

Mycotoxins

fungal toxins

Healthcare Associated Infections

infections acquired by patients (immunocompromised host) while in a hospital or other clinical care facility

affect up to 2 million individuals a year with a 5% mortality rate

sources:

1. catheter associated UTIs

2. surgical site infections

3. central line bloodstream infections

4. C-diff and multidrug resistance infections

5. animate sources - staff, patients, visitors

6. inanimate sources - flowers, food, computers

Where Did Life Come From?

earth is about 4.6 billions years old

microbial cells first appeared 3.7-4.3 billion years ago

atmosphere was anoxic (no oxygen) with few gases present

first autotrophs were anoxygenic (cant produce oxygen)

Cyanobacteria

the earliest O2 producing organisms (oxygenic phototrophs)

arrived 2 billion years ago

Stromatolites

provides evidence of microbes preserved in structures

date back to 3.6 billion years ago

fossilized microbial formations, sticky mats of microbes trap

cyanobacteria-like fossils found in rocks that are 3-3.5 billion years old

LUCA

last universal common ancestor

examination of genes found all three domains have descended from a common ancestor

Stanley Millers Experiment

sent an electrical charge through a flask of a chemical solution of methane, ammonia, hydrogen, and water

replicated what early atmosphere was like

this created organic compounds like amino acids

Fermentation

turning sugars into alcohol using yeast or other microorganisms

first beer factory was created centuries before microorganisms were discovered

Early Notions of Disease

first believed diseases were caused by invisible forces

bad air: miasmatic odors

cloaca maxima: the greatest sewer, ran through ancient rome to carry sewage away from the city

Hippocrates

father of western medicine

dismissed the idea that disease was caused by supernatural forces, thought diseases were caused by internal natural causes from patients or their environment

made hippocratic oath: oath of ethics taken by doctors

Antonie Van Leeuwenhoek

credited as being the first person to observe microbes, including bacteria, which he called animalcules and wee little beasties

Louis Pasteur

credited with numerous innovations including the microbial basis of fermentation, work on spontaneous generation, and development of vaccines like rabies

Robert Koch

first to demonstrate the connection between a single, isolated microbe and a known human disease

ex: anthrax, cholera, and tuberculosis

Taxonomy

classification, description, identification, and naming of living organisms

system of categorizing and naming using a standard format was made by Carolus Linnaeus

Binomial Nomenclature

every organism is assigned two names- a genus name and a specific epithet (species) name

both names are printed underlined or italicized

genus name is always capitalized, species name is lowercase

Prokaryotic

no true nucleus or nuclear membrane

include bacteria and archaea

smaller in size

Eukaryotes

have a true nucleus

microbes include fungi, protozoa, and algae

bigger in size

Bacteria

prokaryotes

found in nearly every habitat on earth, including in humans

cell walls contain peptidoglycan

diverse in appearance and function

common shapes are coccus, bacillus, or spirillum

Archaea

first isolates came from hot, salty, or acidic sites

associated with extreme environments- but not all

lacks any pathogens or diseases

Methanogenic Archaea

common in guts of animals (also humans)

responsible for methane production which can be measured in clinical methane breath analysis

Fungi

eukaryotes

can be unicellular or multicellular

can reproduce sexually or asexually

chitin cell walls

ex: Yeast

• unicellular

• causes bread to rise and fermentation

• diseases like vaginal yeast and thrush

ex: Molds

• multicellular and filamentous

• decompose dead plants and animals

  • causes allergies by producing disease-causing metabolites called mycotoxins

Protists

informal grouping of eukaryotes that are not plants, animals, or fungi

ex: algae and protozoa

Algae

photosynthetic

can be either unicellular or multicellular

cellulose cell walls

Protozoa

very diverse, some are free living or parasitic

photosynthetic, some feed on organic material

mostly harmless, some are disease causing pathogens

move by pseudopods (false feet), flagella (tail), or cilia (hair like)

Helminths

multicellular parasitic worms

eukaryotes

2 major groups: flatworms and roundworms

most are large enough to see without a microscope

dracunculus medinensis (guniea worm)

• caused by nematode roundworm parasite

  • occurs after drinking water containing larvae

Viruses

not cells, acellular

not found on the tree of life

either DNA or RNA, but never both

so small that most can only be seen with electron microscope

obligate parasite: can only replicate within cytoplasm of host

ex: influenza and ebola

Prions

not cells, acellular and not on tree of life

misfolded rogue form of a normal protein (PrPc) found in cells, cant be killed at high temps

genetic mutation or occurs spontaneously, can be infectious, stimulating other endogenous normal proteins to become misfolded forming plaques

cause various forms of transmissible spongiform encephalopathy (TSE)

ex: mad cow disease

Six Rules To Be A Living Organism

1. metabolism: cell is an open system

2. reproduction: cell division

3. differentiation: cell structure such as a spore

4. communication

5. movement: flagella or cilia

6. evolution: indiscriminate use of antibiotics, horizontal gene transfer - transfer of genetic material from donor to recipient