F1 Introduction into microbiology Flashcards
what is biotechnology?
integration of natural sciences and engineering, technological application that uses biological systems, living organisms, or derivates thereof, to make or modify products and process for specific use
red / green / white / blue biotechnology
red = medical green = agricultural white = industrial blue = marine
first / second / third / fourth era of biotechnology
The first era: food products through fermentation (alcohol, cheese)
The second era: organic acids and solvents from microorganisms (from 1890)
The third era: antibiotics (from 1940ies)
The fourth era: genetic engineering (from 1980ies)
microbial production, the proces
substrate -> microorganism (yeast etc) -> product
microbes as cell factories
- engineering of metabolic processes to produce new or modified products
- improved substrate specificity or robustness
- improved transport processes (inside and outside of the cells) to increase the yield of product
- genetic engineering to obtain new products (recombinant products)
what is microbiology?
study of microorganisms
fungi, protist, bacteria and archaea are … microorganisms
cellular
viruses, viroids, satellites and prions are… microorganisms
acellular
taxonomy
science of naming, describing and classifying organisms
phylogeny
study of relationships among different groups of organisms and their evolutionary development
advantages of being small microorganism
- fast growth
- fast nutrient uptake
- one chromosome -> faster mutation rate -> faster evolution
- small enough to colonize any environment (parasites, intracellular)
- minimal cell size 0.2-0.4 µm
prokaryots vs eukaryotes
prokaryotes
- bacteria, archaea
- single-celled organism that lacks a nucleus (cellkärna)
- small
- have a peptidoglycan cell wall (with few exceptions)
- have one haploid chromosome, packed by nucleoid-associated proteins
- have 70S ribosomes
- unicellular
- have no membrane-enclosed organelles
eukaryotes
- organisms whose cells have a nucleus
- may have a cellulose (plants) or chitin cell wall (fungi)
- may have multiple chromosomes, packed by histones and located in the nucleus
- have 80S ribosomes
- multicellular
- have a variety of organelles (mitochondria, chloroplasts)
bacterial morphology
four basic shapes: spherical (cocci), rod-shaped (bacilli), arc-shaped (vibrio), and spiral (spirochete)
common prokaryotic cell arrangements
coccus, diplococcus, tetrad, streptococcus, straphylococcus, bacillus, streptobacillus
bacterial biofilms
En biofilm är ett aggregat eller kluster av mikroorganismer, till exempel bakterier, som gemensamt bildar en skyddande film där bakterierna kan samarbeta metaboliskt
adhesion -> slime formation (EPS) -> biofilm maturation -> release
cells in a biofilm may have different
jobs, still single cells!
archea
- prokaryotes
- similar to bacteria on first sight, but evolutionary closer to eukaryotes
- Pseudopeptidoglycan major cell wall component
- ether-linked phospholipids
- monolayer lipids
- unique metabolism
- often found in extreme environments (unique robust membranes and proteins -> biotechnology!)
- often resistant to antibiotics
examples of yeast
Saccharomyces cerevisiae (baker’s yeast) Candida albicans (pathogen)
examples of algae
Euglena gracilis (model organism) Dinoflagellates (red tide)
examples of protist
Plasmodium flaciparum (malaria) Trypanosoma brucei (sleeping sickness)
eukaryotes (four types)
plants, animals, fungi, protists
use of bacteria in biotechnology
- recombinant production of a range of products, e.g. insulin, antibiotics, amino acids, ethanol
- fermentation applications, e.g. cheese production
use of archaea in biotechnology
source of robust enzymes, e.g. heat-stable DNA polymerases (PCR)
use of fungi in biotechnology
- recombinant production of many products that need a eukaryotic system for production, e.g. glycoproteins
- fermentation applications, e.g. brewing and baking
use of algae in biotechnology
- production of biofuels, e.g. bioethanol
- production of food products and additives
use of protists in biotechnology
source of bioactive molecules, e.g. enzymes
Gram-positive vs Gram-negative bacteria
differences in the cell wall
Gram-positive
- thick peptidoglycan layer
- no outer membrane
- resistant to mechanical stress
Gram-negative
- thin peptidoglycan cell wall
- outer membrane
- robust, difficult to diffuse through
- resistant to chemical stress
- sensitive to freezing
outer membrane is highly …
impermeable
-> Gram-negative bacteria are much more difficult to treat with antibiotics than Gram-positive bacteria
lipopolysaccharides cause strong immune reactions, toxic
transport barrier
Gram staining
fixation -> crystal violet -> iodine treatment (binds to crystal violet and traps it in the cell) -> decolorization (with ethanol or acetone) -> counter stain with Safranin
Gram-positive: purple
Gram-negative: pink
the cytoplasmic membrane
phospholipid bilayer
60% protein
membrane functions
permeability barrier energy metabolism sensing communication motility (= rörlighet) exchange with surrounding
What is the relevance of the cell envelope for biotechnology?
- uptake of nutrients and precursors
- secretion of products and (unwanted) side products
- genetic engineering towards improved uptake/secretion depending on the application
What is the specific relevance of the outer membrane, cell wall, and inner membrane?
- outer membrane: impermeability for chemicals -> chemical resistance, e. g. antibiotics
- cell wall: mechanical robustness -> resistance towards pressure and osmotic shifts, also influences cell disruption for harvesting non-secreted products
- inner membrane: chemical barrier, but much less so than outer membrane; harbors many important processes that need to be functioning for the cells to be healthy/grow/survive stress/take up or secrete products etc.
What could be the advantages and diadvantages of using a Gram-positive bacterium, Gram-negative bacterium, or yeast in biotechnology?
• Gram-positive: fast growth, easy uptake of chemicals, harder to disrupt
• Gram-negative: fast growth, high chemical resilience, easy to disrupt, risk of endotoxin contamination
• yeast: eukaryotic system, expression of eukaryotic gene products, grows slower than many typical industrially
used bacteria
