Alya Raphael
Michael Wittig
BSCI223H
May 7, 2003
 
Final Protocol:  Isolation of Nitrogen-Fixing, Filamentous, Photosynthetic Cyanobacteria of the Order Nostocales


Step 1:  Media preparation
Prepared a liter each of cyanobacteria media and trace metal media both for liquid media and solid plates
Cyanobacteria Media
K 2HPO4 1.5 g
MgSO4 · 7H2O 40.0 mg
CaCl2 · H2O 36.0 mg
Citric acid  6.0 mg
Ferric ammonium citrate 6.0 mg
EDTA (disodium salt) 1.0 mg
Na2CO3 20.0 mg
Trace Metals* 1.0 ml
Purified agar (for solid medium) 10.0 g
Distilled Water 1.0 liter

Trace Metal Mix
H3BO3 2.86 g
MnCl2 · 6H2O 1.81 g
ZnSO4 · 7H2O 222 mg
Na2MoO4 · H2O 39 mg
CuSO4 · 5H2O 79 mg
Co(NO3) 2 · 6H2O 49.4 mg
Distilled Water 1.0 liter
Purified agar (for solid medium) 10.0 g

Step 2:  Sample Collection
Collected samples from still pools of water in direct sunlight or from a fish tank in light

Step 3:  Growth of Organism in Lab
Placed samples in liquid media to allow the concentration of organisms to increase
Allowed one week for growth at room temperature under lights (2,000 to 3,000 lux)
50ul taken from each liquid sample and plated onto cyanobacteria and trace metal media
Allowed growth on plates for one week at room temperature under light (2,000 to 3,000 lux)
Plates wrapped in parafilm to prevent excess drying
Appearance of green growth on cyanobacteria plates indicated successful enrichment of culture

Step 4:  Confirmation
Conducted Gram stain to confirm that organism was Gram negative
Conducted extensive microscopy to identify which type of nitrogen-fixing, photosynthetic, filamentous cyanobacteria was isolated
        Procedure for Identification (see below)**
Searched for cell-differentiation in isolated cyanobacteria

**Procedure:  Identifying Genera of the Order Nostocales (filamentous, nitrogen-fixing, photosynthetic cyanobacteria)
If reproduction is by trichome breakage (hormogonia not produced – no developmental stage) or by germination of akinetes (spore like cells), go to 2
1.If reproduction is by hormogonia that are distinguishable morphologically from the trichomes (adult filamentous chains of cells), with reproduction by trichome breakage and akinete germination also possible, go to 4
2.Terminal heterocysts (differentiated, nitrogen-fixing cells), possibly at both ends of trichomes.  Akinetes (if present) are next to heterocysts, genus Cylindrospermum
Heterocysts interspersed or terminal, akinete (if present) location varies, go to 3
Spherical, oval, or cylindrical vegetative cells, genus Anabaena
3.Disk-shaped, wider than they are short vegetative cells, genus Nodularia
4.Terminal heterocysts; tapering in mature trichomes from heterocyst to tip, genus Calothrix
Untapered trichomes, go to 5
Heavily sheathed trichomes, false branch may occur at intercalary heterocyst, heterocysts at one end of hormogonia filaments only, genus Scytonema
5.  Unsheathed trichomes, no false branching, heterocysts at both ends of hormogonia filaments, genus Nostoc

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