what is microbiology?

week 1

Microbiology

the study of microbes, how microbes interact with environment, humans, and food

Microbes vs microorganism

microbes are everything prokaryotes, eukaryotes, and acellular eg.viruses

acellular

cell free, viroids, prions, viruses

cellular-p

prokaryotes:no nucleus- archaea, bacteria, cyanobacteria

cellular-e

eukaryotes:true nucleus-algae, protozoa, fungi

cellular life

metabolism, growth, reproduction, genetic variation/evolution, adaptation/ response to environment, homeostasis

what is the most abundant macromolecule

polypeptides, subunit-amino acids, enzymes catalyze the vast majority of biochem reactions, about 50% of the cell

categorizing of cellular microorganisms

all cellular life has ribsomes (protein and RNA), more mutation/variations in the SSU rRNA= evolutionary distance between species

Carl Woese

based on the comparison of sequences of small units ribosomal RNA genes (SSU rRNA) (DNA code)

divides microorganisms into 3 domain of life (only cellular)

bacteria, archaea, } prokaryotic, eukarya

phylogenetic tree of life

1) bacteria 2)archaea 3) eukarya

Bacteria

prokaryotes, single-celled, no nuclear membrane, peptidoglycan cell walls, binary fission, uses inorganic, organic or photosynthesis, shapes: bacillus, coccus, spherical, spiral corkscrew, some cause disease

Archaea

prokaryotic, lack peptidoglycan, pseudopeptidoglycan, live in extreme environments, includes: methanogens, extreme halophiles, extreme thermophiles, not known to cause diseases

eukaryotic cells

all contain a nucleus-where genetic material can be contained, have membrane bound organelles

algae

part of eukaryotic group, produce the most oxygen-80%

diatoms

use light as a defense mechanism-lights up when it gets hit

Protozoa

eukaryotes, unicellular, absorb or ingest organic chemicals, may be motile via pseudopods, cilia, or flagella, live freely in water, some live inside animal hosts

fungi

Eukaryotes, chitin cell walls, have a nuclear membrane, uses organic chemicals for energy, molds and mushrooms are multicellular, yeast is unicellular

mold and mushrooms

causes allergies, disease causing

yeast are unicellular

like molds, asexually by budding, useful yeast is saccharomyces, candida albicans-yeast infection

Helminths- foot parasite

microscopic lifecycle-interaction w/ host begins, ingested and grows into multcellular organism in the body

Viruses

not seen until electron microscope in 1932, acellular, consists of DNA or RNA core, surrounded by protein coat, coat may be enclosed in a lipid envelope, can ONLY replicate in a living host cell

naming and classifying

binomial nomenclature system- underlined or italicized

1. the genus- always capitalized

2. the species- not capitalized

3. describes an organism, honors a researcher, or identifies the habitat

Carl Linnaeus

nomenclature for organisms, latinized

writing scientific names

after the first use, the first letter of the genus may be abbreviated

marine microbes

diverse population, thousands more viruses than bacteria, basis of food chain, produce 70-80% of atmospheric oxygen, recycle chemical elements

soil microbes

diverse: 10^6 fungi, 10^9 bacterial cells and 10^10 viruses in one gram of soil, helps break down wastes, incorporate nitrogen gas

human and microbes

trillions of microbes all over the body, more bacterial cells then our own cells

normal microbiota

microbes normally present in and on the normal body, digestive tracts are comprised of dense population of microbes, 10^7-10^12 bacteria stool, symbiotic

effects of human microbes

host nutrition, physiology, immune systems, behavior

autism

diff. microbial biome then children that do not have autism

commensalism

one organism benefits, and the other is unaffected, Staphylococcus

mutualism

both organisms benefit, gut microbes synthesizes vitamin K and vitamin B, large intestines provides home

parasitism

one organism benefits at the expense of the other

biofilms

bacteria secrete sugar, gaining more bacteria, share DNA

biofilm stages

1. attachment

2. growth-encourages adhession and makes biofilm hard to penetrate

3. free-floating cells can be released from the biofilm

Small impact on daily life

common cold, strep throat, ear infections

large historical impacts

yersinia pestis- black death, influenza virus, HIV, Ebola, SARS-CoV-2 caused COVID-19

The black death

killed a third of the population in Europe, Asia, North Africa, a 60 span from 1340 to 1400, started in Asia-trade route,

Alexandre Yersin

identified causative agent of black death from Hong Kong Outbreak

Yersini Pestis

a bacterium that infects rodents and humans, transmitted by flea bites, people- handling bodies, infect animals, inhalation of droplets

Flea and yersinia pestis

1) doesn’t allow for full blood bites 2) throat for good transmission 3)

prefers dry heat

Madagascar endemic

Burial traditions, family handling the deceased, “turning of the bone”

microbial commercial application

Vitamins (vit C- gluconobacter), organic acids, enzymes, alcohols, xanthan gum

Food industry

vinegar, sauerkraut, pickles, soy sauce, cheese yogurt

recombinant DNA techniques plasmid DNA and donor DNA

DNA can be incorporated into linearized plasmid, form a recombinant plasmid, introduced to bacteria, bacteria can express

cell theory

all living things are comprised of cells and come from preexisting cells

Robert Hooke

reported that living things are composed of little boxes, or cells, could only see large cells

antonie van leewenhoek

“father or microbiology,” live microorganisms, first microscope containing glass lenses to magnift specimens

spontaneous generation

the hypothesis that living organisms arise from nonliving matter; a “vital force forms life”

biogenesis

the hypothesis that living organisms arise from preexisting life

francesco redi

decaying meat jars, people believed that fresh air was needed for spontaneous generation(his closed jar had not opening)

John Needham ( famous for being wrong)

heated nutrient broth, poured it into sealed flask, growth occurred from the dirty flask

Lazzaro spallanzani

nutrient both heated in the flask, no growth, Needham said the seal prevented the “vital force”

Louis Pateur

demonstrated that microorganisms are present in the air, S- flasks allowing air to enter but dust and microbes trapped

John Tyndall

showed that if dust is absent nutrient broths remained sterile, even if directly exposed to air

Ferdinand Cohn

heat resistant bacteria could produce endospore (allow bacteria to survive extreme stress)

fermentation

conversion of sugar to alcohol to make beer and wine

yeast converts sugar to alcohol

microbial growth is also responsible for spoilage of food

bacteria that use alcohol and produce acetic acid

spoil wine by turning it into vinegar

pasteurization

is the application of a high heat for a short time, heat beer and wine just enough to kill most of the bacteria but not enough to evaporate the wine

Germ theory of disease

states that microbes cause infectious disease

Ignaz semmelweis

advocate hand washing to prevent transmission of childbed fever

Joseph Lister

used a chemical disinfectant to prevent surgical wound infections

Florence Nightingale

established aseptic techniques in nursing, founder of modern nursing