KINGDOM MONERA AND VIRUSES

 

CHAPTER 17 STERN

 

 

 

I.     Features of the Kingdom Monera:

viruses, bacteria, blue-green bacteria (algae)

A.        Prokazyofic cells - cells have no nucleus, Plastids

  - do have ribosomes, plasmids,

 

           Table 17. 1, pg. 248: prokaryotic cell vs eukaryotic cell

 

B.        Cellular arrangements:

1.    single cells

2.    filaments

3.    clumps

4.    strepto - preflx indicating a chain type colony

5.    staph - prefix indicating a clump type colony

6.    often cell or colony encased by a gelatinous material

 

C.    Nutrition:

1.    extracellular digestion - digestion of food takes place outside of the organism; digestive juices secreted outside of the organism, digestion takes place, digestant is then absorbed

2.    food habit:

saprophytic

parasitic

autotrophic - make their own chemical energy (ATP)

photosynthesis

chemosynthesis

D.    Reproduction:

1.    asexual by:

a)      binary fission

b)      formation of spores

c)      fragmentation

d)      hormogonia

2.    sexual - very primitive (haploid organisms)

bacteria - sex pilus

- transformation

- Umsduction

11. Bacteria:

 

A. two distinct groups:

Archaebacteriobionta - very primitive bacteria

- DNA/RNA distinctly different dm Eubacteria

- lack muramic acid in cell wall

- unique lipids in cell wall

1.      Methane Bacteria:

2.      Salt Bacteria

3.      Sulpholobus Bacteria

Eubacteriobionta - true bacteria

 

B.  about 4000 species

 

C.  occur in almost all habitats (bacteria, microbes, are found everywhere)

 

D. food habit: free living saprophytes, parasites, pathogens, some live symbiotically - mutualism

 

E.  nucleoid - single "chromosome", very condensed DNA ring - no histories

plasmids may also be found in the cell - small, circular, extrachromosomal DNA loops

 

  F.   reproduction:

1. asexual - binary fission

2. sexual:

conjugation - sex pilus

transformation

transduction

 

III.       Cellular Detail and Reproduction

 

A.   Cell Structure

1. Prokaryotic

- no membrane-bound organelles

 

2. Nucleoid

- single chromosome (long, very condensed DNA molecule in ring form)

 

3. Plasmids

- small, circular, extrachromosomal DNA molecules

 

B.  Reproduction

1.      By binary fission

- a bacterium may undergo fission every 10-20 minutes

 

2.    Conjugation

- part of a chromosome is transferred from donor cell to recipient through pilus

 

3.    Transformation

- living cell picks up fragments of DNA released by dead cells

 

4.    Transduction

- fragments of DNA carried from one cell to another by viruses

 

IV.     Size, Form, and Classification

A. Size

- most are less than 2-3 [im in diameter, the smallest being around 0.15 µm

 

B. Form

1. Cocci

spherical

2. Bacilli

  rod-shaped or cylindrical

3. Spirilli

  helical or spiral

 

              C.  Classification:

                             1.  Initial classification based on a reaction to a dye (Gram reaction)

                             2.  Gram reaction: based on differential staining using two different stains

                                           a.  Gram-positive  - stained by the primary stain, crystal violet,  are blue in color

                                           b.  Gram-negative - stained by the secondary stain, saffron,  are red in color

                             3.  Stain named after Christian Gram - made observation in 1884

 

V.  Subkingdom Archaebacteriobionta: the Archaebacteria

              A.  Distinctive characteristics:

                             1.  Unique sequences of bases in RNA

                             2.  metabolism different than other prokaryotes

                             3.  cell wall lacks muramic acid

                             4.  production of distinctive lipids

              B.  3 general categories:

                             1.  Methane Bacteria:

                                           a. Obligate anaerobes (no O2)

                                           b.  Produce methane from CO2 and H2

                             2.  Salt Bacteria:             

                                           a.  Thrive in high salinity

                                           b.  Carry on photosynthesis with the aid of bacterial rhodopsin

                             3.  Sulpholobus Bacteria:

                                           a.  Occur in sulphur hot springs (80-90oC)

                                           b.  acidic environment - pH - <2

                                           c.  thermoplasma - no cell wall

 

VI.  Subkingdom Eubacteriobionta: The true bacteria (Division - Eubacteriophyta)

              A.  Class Eubacteria - the unpigmented, purple, and green sulphur bacteria

                             1.  muramic acid in cell wall

                             2.  Base sequences in RNA like other organisms on earth

                             3.  Food habit:

                                           a) heterotrophic mostly

                                                         (1) saprobes

                                                         (2) parasites

                                           b) autotrophs:

                                                         (1) include the purple sulfur, purple nonsulfur, green sulfur

                                                         (2) sulfur bacteria: photosynthetic bacteria that have bacteriochlorophyll that produces NO O2

                                                                                      (3) other photosynthetic bacteria produce O2, others sulfur

                                                         (4) in photosynthetic bacteria, pigments for photosynthesis located in thylakoids

                                                         (5) chemoautotrophic bacteria:

                                                                        - obtain energy through oxidation of reduced inorganic groups (NH3, H2S, Fe++, H2)

                                                                        - examples: iron bacteria

                                                                                             sulfur bacteria

                                                                                             hydrogen bacteria

                             4.  True bacteria and disease:

                                           a) modes of access

                                                         (1) through the air, ex. Strep throat, chlamydia)

 

 

                                                         (2) through contaminated food or drink

                                                                        Ex.         Salmonella

                                                                                      Staphylococcus food poisoning

                                                                                      Legionnaire’s disease

                                                                                      Botulism

                                                         (3) access through direct contact

                                                                                      Syphilis

                                                                                      Gonorrhea

                                                                                      Anthrax

                                                                                      Brucellosis (undulant fever)

                                                         (4) access through wounds

                                                                                      Tetanus

                                                                                      Gas gangrene

                                                         (5) access through bites of insects or other organisms

                                                                                      Bubonic plague (black death)

                                                                                      Tularemia - ticks, dear flies

                                                                                      Rickettsias - typhus, spotted fever

                                                                                      Pleuropneumonia - like organisms (PPLOs)

                                                                                                    no cell wall

                                                                                                    Penicillin resistant

                                                                                      Lyme disease

              B. Koch’s postulates:

                             1.  Microorganism must be present in all cases of the disease

                             2.  Microorganism must be isolated from the victim in pure culture

                             3.  Microorganism from pure culture, when injected into susceptible host, must produce the disease in the host                                                                                

                             4.  Microorganism must be isolated from the experimentally infected host and grown in pure culture

              C.  True bacteria useful to humans:

                             1.  Biological control:

                                           a) Bacillus thuringiesnsis used in control of caterpillars

                                           b) Bacillus thuringiensis, var. Israelensis, used in control of mosquitoes (genetically engineered)

                                           c) Bacillus popilliae used in control of Japanese beetle grubs

                             2.  Bioremediation (breakdown of toxic wastes and pollution)

                                           a) certain bacillus will break down nitroglycerin and trinitrotoluene

                                           b) Pseudomonas capacia breaks down petroleum pollution

                             3. Dairy industry (mutualism within rumen, 1st stomach of ruminants)

                                           a) cheese

                                           b) yogurt

                             4. Production of metabolic wastes with industrial use

                             5. Food production

 

VII.  Class Cyanobacteriae, the blue-green bacteria (1500 species)

              A.  Pigments:

                             1. Chlorophyll a

                             2. Phycocyanin (blue-green pigment)

                             3. Phycoerythrin (red pigment)

              B. Many can fix nitrogen and produce oxygen

 

              C. Habitat:

                             1. Mostly fresh water

                             2. Few marine species

                             3. Few terrestrial species

              D. Plant body:

                             1. single celled

                             2. cells often occur in chains or hair-like filaments (trichomes)

                             3. some species occur as floating colonies, ex Nostoc

                             4. Color varies depending on pigments present, although most are blue-green

              E. Food storage produce - cyanophycin mostly

                             few store other carbohydrates, and oil

              F. Reproduction: (mostly asexual)

                             1. New cells formed by fission

                             2. Colony reproduction:

                                           Akinetes

                                           Hormogonia

                                           Fragmentation

              G.  Blue-green bacteria/chloroplast/O2:

                             1. Theory supported by ample scientific evidence suggest an endosymbiosis origin of the chloroplast of high plants

                             2. chloroplast had it origin as a free living blue-green bacterium

                                           * blue-green bacteria occur symbiotically and function essentially as chloroplast in host organism

              H.  Importance to man:

                             1.  Occur at bottom of food chain

                             2.  Production of blooms

                             3. Poisons

                             4. Spirulina used as food

                             5. Undesirable effects in human water supplies

                             6.  Nitrogen fixation

 

VIII.  Class Prochlorobacteriae - the Prochlorobacteria

              A. Discovered living in sea squirts in 1976

              B.  Have chlorophyll a & b, but not phycobillins

              C.  Thylakoid membranes double, unlike thylakoids of blue-green bacteria

              D.  One very abundant form found at depth of 100 m in ocean waters

 

IX.  Viruses: