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45 Cards in this Set
- Front
- Back
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What are cyanobacteria (formerly known as blue green algae) |
Photosynthetic non-flagellated organisms |
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What do cyanobacteria resemble |
Eukaryotic algae except in their cytology and genetics |
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Why does cyanobacteria enrichment conditions differ greatly from those for all other photosynthetic bacteria? |
Because tey evolve O2 in photosynthesis (using H2O as an electron donor) |
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What are the three groups of cyanobacteria |
1) Unicellular forms with no specialized cells and little or no motility 2) Unbranched filamentous forms with no specialized cells and which move by gliding except when surrounded by an obvious sheath 3) Filamentous forms which produce occasional or numberous heterocyts sometimes resting spores and with gliding motility seen only periodically in special short filaments |
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What are heterocyts
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Clearer, thciker walled cells |
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What are the major photosynthetic harvesting pigments of the cyanobacteria? |
Chlorophyll and blue pigment phycocyanin |
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What is something else that cyanobacteria carry |
Red pigment phycoerythrin |
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Each species of cyanobacteria is usually restricted in type of ______
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Habitat |
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Any inoculum of cyanobacteria contains what |
A limited number of species |
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What are the sources for cyanobacteria |
Winogradsky or hot spring colums
Damp soil samples Pond or lake water or mud Hot spring mats Damp shaded rocks Estuarine and marine sediments Hypersaline mats etc |
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What is the basal medium |
BG-11 or SWBG-11 |
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Why is BG-11 a "mineral" medium |
Will nto support heterotrophs due to absence of organic carbon |
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What is the enrichment for cyanobacteria? |
Inoculate a flask of medium with a few drops or loops of source water or mud and incubate in light |
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What does addition of 5.6 mg of amphoteracin B per liter of medium do |
Initiatlly inhibit the growth of most eukaryotic algae, thus selecting for the cyanobacteria in the inoculum |
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How can many non-motile unicellular cyanobacteria be isolated |
By standard manual dilution methods (IE streaking, plating, surface-pour, shake cultures, etc)
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Many filamentous forms exhibit ______ |
Gliding motility
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For the filamentous forms that exhibit gliding motility will they isolate themselves on agar plates |
Yes |
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For fast moving types what isolation needs to be made |
Manual isolation may have to be made within a few to several hours after inoculation; otherwise isolation is done in one of the a few days |
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Are motil filaments that have moved across or through the agar and are farthest from the source the least or most likely to carry heterotrophic bacteria or other contaminants |
Least |
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Other filaments may do what |
Slowly outgrow contaminents on or within the agar |
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How do you isolate the slowly outgrowing contaminents filaments |
Cutting off the tips of the spreading filaments under the dissecting scope using a watchmaker's forceps |
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For incubation temperatures of 50 C or above, where to enclose plates
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ZipLok bags |
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What position should plates be incubated in |
Inverted |
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When will visible colonies from single cells or small groups of cells appear
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A few weeks |
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Should process be repeated |
Yes
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What does the enrichment we use during the purple non-sulfur bacteria (rhodospirillaceae) provide for |
The photoheterotrophic growth of various purple non-sulfur bacteria and selects against other phototrophs
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What carbon sources are rhodospirillaceae use |
Organic |
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What is concentration of sulfate kept at for the purple non-sulfur bacteria |
Kept low
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What does DCMU select against |
Cyanobacteria |
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How does DCMU select against cyanobacteria |
By inhibiting photosystem II Also the high organic concentration inhbiits most cyanobacteria |
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What are the varaibles in the series of enrichments |
Carbon source pH |
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the base medium 1 used during the rhodospirillaceae conains what |
DCMU Vitamins |
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The complete medium will have either _____ or ____ as _____ |
*Malate (M) *Citrate (C) *Non-fermentable carbon source |
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What does the non-fermentable carbon source prevent |
Competition form heterotrophic fermentative bacteria |
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How do we insure anoxic conditions |
By adding a drop or two of sodium ascorbate solution before sealing
The ascorbate consumes O2 |
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What are we checking after a week for |
red, organge or yellow growth |
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For isolation fo rhodospirillaceae what isolation |
Using an agar-solidified medium of the same compositon, streak and incubate in illuminated GasPaks |
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If your enrichment is heavily inoculated what should you do |
Start a second enrichment by transferring a few drops of the first enrichment to the same medium and streaking form this enrichment later |
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What is R. palustris |
One of the few photoheterotrophic bacteria that can utilize the aromatic compounds benzoic acid or cinnamic acid as sole carbon sources |
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What is the process of R palustris like |
Stirctly anaerobic
Light dependent |
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What does metabolism of either benozic acid or cinnamic acid involve |
Complete reduction of the benzene ring followed by opening to form pimelyl CoA and then acetyl CoA |
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What kind of bacterium is Rhodomicrobium vannielii |
Photosynthetic bacterium |
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The single cells of rhodomicrobium vannielii produce what |
Elongate tubes (hyphae) into which replicated nucleoid migrates; a new cell then buds, which may detach as a flagellated swarmer cell |
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R vannielii has been used for the study of what |
Sequential gene expression; the growing branching phase alternates with the swarm cells in which there is no DNA or rRNA synthesis and much reduced rate of transcription and translation |
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What is the carbon source for R vannielii
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Malate |
