1. Bacteria and Archaea Prokaryotic organisms
Premedical - Biology

2. They are (almost) everyvwhere!
Their history starts 3,5 billions years ago
Dominate the biosphere
Inhabit the human mouth or skin, digestive system – 500 – 1,000 species
Only minority ot them cause disease in humans or any other organism

3. They are able to adapt in structure and function, in nutrition and metabolism
Reproduction, mutation and genetic recombinatoin promote genetic diversity

4. Bacterial structure

5. Prokaryotes unicellular groups of two or more cells, true colonies
sphere (cocci)
rods (bacilli),
helices (spirilla, spirochetes)
0.5-5μm
(10-100μm for eukaryotic cells)
Staphylococcus aureus

6. Cell walls protection (hypotonic enviroment)
would die in hypertonic medium (heavily salted meat)
different from plant, fungi, protists cell walls
peptidoglycan (polymers of sugar cross-linked by short
peptides that vary from species to species)
Tool in microbial taxonomy is Gram stain – separate
into two groups based on differencies in cell walls
Gram positive – large amount of peptidoglycan
Gram negative – less peptidoglycan, outer membrane
of lipopolysaccharides (LPS), carbohydrates bonded
to lipids, Lipoteichoic acids (LTA)

7. Gram positive and Gram negative
krystalová violeť, lugoluův roztok, alkohol a karbolfuchsin: Gramm staining
Violet dye, iodine, alcohol and red dye
Gram pozitive are blue or violet
Gram negative are red

8. Patogenity Gram negative are more threatening
LPS of negative are often toxic
Outer membrane is protect against hosts and antibiotics
Antibiotics, like penicillins, inhibit synthesis of cross-
links in peptidoglykan and prevent the formation
Capsule - adherention to substrate, protection, gelatinous
glue the cells to colonies
Pili, pilus - adherention, to mucous
membrane, conjugation – DNA transfer
some product antibiotics

9. Pathogenic prokaryotes
Cause about one half of all human diseases
Some pathogen are opportunistic
– normal residents of a host, but can cause illness,
when the host‘s defences are weakened.
Pathogen caused illnesses by producing
Exotoxins: proteins secreted by prokaryotes, (botulism, cholera)
Endotoxins – components of the outer membranes of certain Gram-negative bacteria (Salmonella)

10. Movement second Flagelar action - most common mechanism, scattered
directional movement – 100 times their body length per
second
Flagelar action - most common mechanism, scattered
over the entire cell surface or at one or both
ends of the cell
The flagella of prokaryotes
and eukaryotes differ
in function and structure
Half of prokaryotes prokaryotic flagella are one-tenth the width of those of eukaryotes and are not covered by plasma membrane
When filaments rotate, the cell movers like a corkscrew,
disks rotate in the opposite direction

11. motility of spirochetes – two or several helical
filaments under the outer
sheath of the cell
taxis movement – toward
or away from stimulus
chemotaxis
phototaxis
                                                                   
Spirochetes – helical shaped bacteria,
undulating membrane

12. Genomic organization Not true nuclei enclosed by membranes
Not compartmentalization by internal membrane systems
DNA is concentrated in nucleoid region – prokaryotic
chromosome – one double stranded molecule
in the form of ring
essential functions programmed by chromosome
small rings of DNA – plasmids – resistance to
antibiotics, metabolism of unusual nutrients
Replicate independently of the main chromosome
Infoldings of membrane functionin in cellular respiration
Thylakoid membrane systém in photosynthesis
Join on chromosome

14. Division binary fission – „division in half“
generation time is measured in minutes or hours
bacterial chromosome is attached to the plasma membrane
Synthesize DNA almost continuously

15. Grow of populations
temperature, pH, salt concentrations, nutrient sources
More multiplication of cells than to the enlargement of individual cells
Generation time in the range of 1 to 3 hours, number of cells doubling with each generation
During lag phase, bakteria adapt
themselves to growth conditions
Exponential phase is a period
characterized by cell doubling
During stationary phase,
a result of nutrient depletion
and accumulation of toxic products
At death phase, bacteria run out of nutrients and die
Aplied to prokaryotes

16. Endospores
The ability of some prokaryotes to withstand hard conditions
The cell replicates chromosome, the copy became surrounded by a durable wall, outer cell disintegrates, endospore contained survives all sorts of trauma:
lack of water, nutrients, extreme heat or cold, almost poisons
Clostridium tetani
Bacillus cereus, Bacillus subtilis.
Germination
Boiling water in a relatively short length of time is not hot enough
Sometimes the endospore can be so large the cell can be distended around the endospore, this is typical of Clostridium tetani.
(1, 4) central endospore; 2, 3, 5) terminal endospore; (6) lateral endospore

17. Sporulation
nucleoid gets fibrous shape, instead of the originally spherical; nucleoid division and cell division septum in two differently sized parts, the larger (parent) is the sporangium and the smaller is the future of the spore; future spore move in a larger parent cells, the process of sporulation is irreversible; in the space between two membranes arises peptidoglycan cortex, accumulate calcium; outer membrane protein forms of housing cover; spore acquires the typical characteristics - dehydration, resistance to external factors; lysis (destruction) of the parent cells, the spore is released; as the zero stage in the vegetative stage indicates the (original) cell.

18. Grow of populations prokaryotes lack sexual cycle, important source
of genetic variation
Three mechanisms of genetic recombination
Transformation – genes are taken up from surrounding
environment
Conjugation – genes are transferred directly from one
to another
Transduction – genes are transferred
between prokarytoes
by viruses
The union of haploid nuclei

19. Bacterial transformation
naked DNA passess into recipient cells,
Griffith (1928) 1. experiment
Avery, McLeod, McCarthy
(1944) – the same effect with isolated DNA
finally homologous recombination:
the exchange of homologous parts

21. Transduction Bacteriophages transmit spontaneously bacterial genes
Special – restrictions mistakes within cutting out of bacteriophage from bact. genome
General – into small parts of phages particles is packed bacterial DNA instead of phages one

22. Bacterial conjugation
Donor’s plasmid F+ passes into acceptor’s cell F-,
Conjugation by cytoplasmatic conjugative bridge
there is the exchange of homologous parts

23. How an organism obtain two resources for synthesizing organic compounds: energy and a source of carbon

24. Marine and halophilic prok. plants algae Certain Fungi, animals,
Phototroph - use light energy
Chemotroph – energy from chemicals from environment
Certain
prokaryotes
Fungi, animals,
most protist,

25. Photoautotrophs Photoheterotrophs Chemoheterotrophs
use light-energy to drive synthesis of organic compounds from carbon dioxide; internal membranes with light-harvesting pigment systems; Chemoautotrophs
need only CO2 as a carbon source, obtain energy by oxidizing inorganic substances: hydrogen sulfide (H2S), ammonia (NH3), ferrous ions (Fe2+)
Photoheterotrophs
use light-energy to generate ATP, but must obtain carbon in organic form;
Chemoheterotrophs
must consume organic molecules for both energy and carbon

26. Metabolism
Metabolic diversity is greater among prokaryotes than all eukaryotes combined.
Able to use various organic and inorganic molecules from the atmosphere (CO2, N2)
Primary metabolism: anaerobic, heterotrophic
than autotrophic
Anaerobic bacteria - some disappeared, inhabition anaerobic environments, symbiosis, parasitism

27. Many prokaryotes are symbiotic
Symbiosis „living together“- ecological relationships between organissm of different species that are in direct contact; symbionts – if one is much larger than the other, the larger is termed host
Mutualism - both symbionts benefit
Commensalism - one symbionts receive benefits while neither harming nor helping the other in any significant way
Parasitism – one symbiont, called a parasite, benefits at the expense of the host; patogene

28. Metabolic relantioship to oxygen
Obligate aerobs – cellular respiration
Facultative anaerobs – if it is present, use it. They use fermentation in an anaerobic enviroment
Obligate anaerobs are poisoned by oxygen, use fermentation or extract energy
by anaerobic respiration – inorganic molecules accept electrons
fakultativ

29. Autotrophic Bacteria
organism that makes organic compounds from inorganic sources
synthesize organic compounds from carbon dioxide and other inorganic elements (CO2, H2S) or molecules
using either light energy or chemical energy.
green sulphur bacteria, purple sul-phur bacteria and the purple norisulphur bacteria,

30. Heterotrophic Bacteria
the majority are chemoheterotrophs
organism that cannot make organic compounds from inorganic sources.
They depend on small or large molecules which they have to absorb.
There are three types of heterotrophic bacteria : saprophytic or saprobic, parasitic and symbiotic.
Pseudomonas, Staphylococus, Escherichia coli

31. Prokaryotes, Archae and Eubacteria
Common ancestor 3,5 bilion years ago

32. Archae
Two branches of prokaryotic evolution were identified by comparing ribosomal (16S-rRNA) RNA and completely sequences genomes of several extant species.
Archaea inhabit extreme inviroments, hot springs and salt ponds
Archea have at least as much in common with eukaryotes as they do with bacteria; have many unique traits.

33. Phylogeny of prokaryotes
domain Archea
Methanogens – unique form of energy metablism, H2 is used to reduce CO2 to methane CH4. Oxygen is a poison. Live in swamps and marshes and other species inhabit the gut of animals.
Extreme halophiles – live in saline places as the Great Salt Lake and the Dead sea
Extreme thermophiles – thrive in hot enviroments, temperatures are of 60°C to 80°C, thermal springs

34. domain Bacteria – five groups of Bacteria (based mainly on comparision of sequences in ribosomal RNA
1. Proteobacteria
purple bacteria – photoautotrophs, photoheterotrophs
with bacteriochlorophylls, obligate anaerobes
chemoautotrophic proteobacteria – free-living and
symbiotic species, nitrogen fixation
chemoheterotrophic proteobacteria – enteric
bacteria, facultative anaerobes
(Salmonella, E. coli)
Black colonies with methal shine, Endo agar with the red lactose-positive colonies
Mikrobial tampon from swab,
Single, separate
nutritive plating media, agars selective differential and non-selective

35. 2. Gram-positive bacteria
Some are gram-negative, some are photosynthetic,
most are chemoheterotrophs (Clostridium, Bacillus)
Mycoplasmas
– the smallest of known cells,
μm, only bacteria that lack cell walls
Actinomyces
Soil bacteria resemble fungi,
commercial sources of antibiotics

36. 3. Cyanobacteria 4. Spirochetes
Photoautrophs with plant-like photosynthesis,
fresh water, marine species, symbionts,
single-cell from, colonies and truly multicellular organisms
4. Spirochetes
Helical chemoheterotrophs, some are very long (up to 0.25mm), internal flagelar-like filments providing corkscrew-like movement, Treponema pallidum, Borrelia Burgdorferi
(jukariəts), (saiənəbæktiəriə),(helikl) ( kórkskrú)
Rod = kind
Druh = sort, kind
Subspecies = třída
Not on solid medium, need liquid special medium
Dark-field microspoce, light refraction

37. 5. Chlamydias
Obligate intracellular parasites of animals, obtain ATP from the host cell, gram-negative, Chlamydia trachomatis cause blindness and sexually transmitted disease

38. Research and technology
Simple model systems
Escherichia coli – the prokaryotic „ white rat“
Soil bacteria called pseudomonas decompose pesticides, petroleum componeds and other.
The food industry uses bacteria to convert milk to yogurt and various kind of cheese.
magnification
Gram stain of yogurt, 1000x with Lactobacillus acidiphilus

39. Most widely known pathogenic bacteria:
Borrelia burgdorferi – Lyme disease
Treponema pallidum - syphilis
Neisseria gonorrhoeae - gonorrhoea
Neisseria meningitis – cerebro-spinal meningitis
Salmonella typhi – typhus
Bordetella pertusis – whooping cough
Staphylococcus aureus – skin suppuration
Staphylococcus pneumonie – pneumonia
Streptococcus pyogenes – angina, sore throat
Streptococcus pneumonie – pneumonia

40. Clostridium tetani - tetanus Clostridium botulinum- botulism
Bacillus anthracis - anthrax
Mycoplasma pneumonie – pneumonia
Shigella dysenterie- red pestilence, dysentery
Vibrio cholerae – cholera
Mycobacterium leprae - leprosy
Mycobacterium tuberculosis - tuberkulosis
Corynebacterium diphterie - diphtheria
Haemophilus influenzae – inflammation of airways
Rickettsia prowazeki - spotted fever
Pasteurella (Versinia) pestis – plague
Francisella tularensis - tularemia
Liprosy, diptiria

41. Campbell, Neil A. , Reece, Jane B. , Cain Michael L
Campbell, Neil A., Reece, Jane B., Cain Michael L., Jackson, Robert B., Minorsky, Peter V., Biology, Benjamin-Cummings Publishing Company, 1996 –2010.