Bacteria and Archaea Prokaryotic organisms
description
Transcript of Bacteria and Archaea Prokaryotic organisms
![Page 1: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/1.jpg)
Bacteria and ArchaeaProkaryotic organisms
Premedical - Biology
![Page 2: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/2.jpg)
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
![Page 3: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/3.jpg)
• They are able to adapt in structure and
function, in nutrition and metabolism
• Reproduction, mutation and genetic
recombinatoin promote genetic diversity
![Page 4: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/4.jpg)
Bacterial structure
![Page 5: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/5.jpg)
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
![Page 6: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/6.jpg)
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)
![Page 7: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/7.jpg)
Gram positive and Gram negative
![Page 8: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/8.jpg)
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
![Page 9: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/9.jpg)
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)
![Page 10: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/10.jpg)
Movement• 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 cellThe flagella of prokaryotes and eukaryotes differ in function and structure
![Page 11: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/11.jpg)
• motility of spirochetes
– two or several helical
filaments under the outer
sheath of the cell
• taxis movement – toward
or away from stimulus
chemotaxis
phototaxis
![Page 12: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/12.jpg)
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
![Page 13: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/13.jpg)
![Page 14: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/14.jpg)
Division• binary fission – „division in half“
generation time is measured in minutes or hours• bacterial chromosome is attached to the plasma membrane
![Page 15: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/15.jpg)
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
![Page 16: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/16.jpg)
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.
(1, 4) central endospore; 2, 3, 5) terminal endospore; (6) lateral endospore
![Page 17: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/17.jpg)
Sporulation
![Page 18: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/18.jpg)
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
![Page 19: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/19.jpg)
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
![Page 20: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/20.jpg)
![Page 21: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/21.jpg)
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
![Page 22: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/22.jpg)
Bacterial conjugation
• Donor’s plasmid F+ passes into acceptor’s cell F-,
• Conjugation by cytoplasmatic conjugative bridge
• there is the exchange of homologous parts
![Page 23: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/23.jpg)
How an organism obtain two resources for
synthesizing organic compounds: energy and a
source of carbon
![Page 24: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/24.jpg)
plants algae
Certain prokaryotes
Marine and halophilic prok.
Fungi, animals, most protist,
![Page 25: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/25.jpg)
Photoautotrophs 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
![Page 26: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/26.jpg)
• 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
Metabolism
![Page 27: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/27.jpg)
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
Many prokaryotes are symbiotic
![Page 28: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/28.jpg)
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
![Page 29: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/29.jpg)
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,
![Page 30: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/30.jpg)
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
![Page 31: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/31.jpg)
Prokaryotes, Archae and Eubacteria
Common ancestor 3,5 bilion years ago
![Page 32: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/32.jpg)
– 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.
Archae
![Page 33: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/33.jpg)
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
![Page 34: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/34.jpg)
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.
Gram stain of yogurt, 1000xwith Lactobacillus acidiphilus
![Page 35: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/35.jpg)
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
Most widely known pathogenic bacteria:
![Page 36: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/36.jpg)
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
![Page 37: Bacteria and Archaea Prokaryotic organisms](https://reader035.fdocuments.net/reader035/viewer/2022062309/56814611550346895db31edd/html5/thumbnails/37.jpg)
Campbell, Neil A., Reece, Jane B., Cain Michael L., Jackson, Robert B., Minorsky, Peter V., Biology, Benjamin-Cummings Publishing Company, 1996 –2010.