Cultures maintenance, media
Cultures maintenance conditions
- Strains are kept in tubes or in 100 ml Erlenmeyer flasks placed in racks with glass shelves.
- The cultures are maintained in air-conditioned rooms, with a temperature regime of 21°C (some strains, mainly cyanobacteria, freshly prepared cultures for customers) or 16°C (most cyanobacteria and algae strains for long-term maintenance). Polar strains are maintained in glass fridges at temperatures around 10°C.
- The cultures are irradiated by a panels of LED light tubes that gives cca 15 - 35 μmol photons m−2 s−1, light is controlled to 12h/12h light/dark cycle.
- Strains are transferred to fresh media in cca 3-4 months intervals.
Media receipts
-
Any nutrient solution can be used as liquid, or solidified by 1.5% of agar. In this case medium is labeled "agar".
Galdieria medium - modified
Authors: Gross, W. & Schnarrenberger, 1995
Dissolve chemicals in 500 ml of distilled water. Add 2,07 ml of Fe-EDTA solution and 2,00 ml trace metal solution. Make up to 1000 ml. Autoclave.
Component |
Quantity Used |
---|---|
(NH4)2SO4 | 1,5 g |
MgSO4.7H2O | 0,3 g |
KH2PO4 | 0,3 g |
CaCl2.2H2O | 0,02 g |
Fe-EDTA (see following recipe) | 2,07 ml |
Trace metals solution (see following recipe) | 2,00 ml |
Fe-EDTA solution
To 50 ml od dH2O add following component and fill in with dH2O do 100 ml.
Component |
Quantity Used |
---|---|
KOH (1 N solution) | 5,4 ml |
FeSO4.7H2O | 0,5 ml |
EDTA (no Na-EDTA!) | 0,52 g |
Trace metals solution
Component |
Quantity Used |
---|---|
H3BO3 | 0,31 g |
MnSO4.4H2O | 0,223 g |
Na2WO4.2H2O | 0,003 g |
(NH4)6Mo7O24.4H2O | 0,0088 g |
KBr | 0,0119 g |
KI | 0,0083 g |
ZnSO4.7H2O | 0,0287 g |
Cd(NO3)2.4H2O | 0,0154 g |
Co(NO3)2.6H2O | 0,0146 g |
CuSO4.5H2O | 0,0125 g |
NiSO4(NH4)2SO4.6H2O | 0,0198 g |
Cr(NO3)2.7H2O | 0,0037 g |
V2O4(SO4)3.16H2O | 0,0035 g |
Al2(SO4)3K2SO4.24 H2O | 0,0474 g |
Literautre:
- Gross, W. & Schnarrenberger, C. 1995. Heterotrophic Growth of Two Strains of the Acido-Thermophilic Red Alga Galdieria sulphuraria. Plant Cell. Physiol. 36(4): 633 - 638.
S medium
Dissolve the chemicals in 500 ml of distilled water, add 1 ml of trace metals solution and make up to 1000 ml. Autoclave.
Component |
Quantity Used |
---|---|
KCl | 1,0 g |
NaHCO3 | 16,8 g |
K2HPO4 | 0,5 g |
NaNO3 | 2,5 g |
K2SO4 | 1,0 g |
NaCl | 30,0 g |
MgSO4.7H2O | 0,18 g |
FeSO4.7H2O | 0,018 g |
EDTA | 0,08 g |
Trace metal solution | 1 ml |
Trace metals solution
Component |
Stock solution |
Quantity Used |
---|---|---|
H3BO3 | - | 2,860 g |
MnCl2.4H2O | - | 1,810 g |
ZnSO4.7H2O | - | 0,220 g |
CuSO4.5H2O | 79,0 | 1 ml |
Na2MoO4.2H2O | - | 0,391 g |
Co(NO3)2.6H2O | 49,4 | 1 ml |
Z medium
Authors: Zehner & Staub 1961
For most of cyanophytes.
Into 900 ml of dH2O add 10 ml of first six stock solutions. Add 1 ml of rest solutions. Autoclave. The final pH should be 6,6
Component |
Stock Solution |
Quantity Used |
---|---|---|
NaNO3 | 46,7 | 10 ml |
Ca(NO3)2.4H2O | 5,9 | 10 ml |
K2HPO4 | 3,1 | 10 ml |
MgSO4.7H2O | 2,5 | 10 ml |
Na2CO3 | 2,1 | 10 ml |
Fe-EDTA solution | see following recipe | 0,2 ml |
Trace metals sollution | see following recipe | 0,08 ml |
Fe-EDTA solution
Component |
Quantity Used |
---|---|
HCl (35%) | 2,2 ml |
dH2O | 250 ml |
FeCl3.6H2O | 4,5 g |
Na2EDTA | 4,65 g |
Trace metals solution
Component |
Quantity Used |
---|---|
H3BO3 | 0,31 g |
MnSO4.4H2O | 0,223 g |
Na2WO4.2H2O | 0,003 g |
(NH4)6Mo7O24.4H2O | 0,0088 g |
KBr | 0,0119 g |
KI | 0,0083 g |
ZnSO4.7H2O | 0,0287 g |
Cd(NO3)2.4H2O | 0,0154 g |
Co(NO3)2.6H2O | 0,0146 g |
CuSO4.5H2O | 0,0125 g |
NiSO4(NH4)2SO4.6H2O | 0,0198 g |
Cr(NO3)2.7H2O | 0,0037 g |
V2O4(SO4)3.16H2O | 0,0035 g |
Al2(SO4)3K2SO4.24 H2O | 0,0474 g |
Literature:
- ANDERSEN, R.A. [ed.] 2005. Algal culturing techniques. Elsevier, Amsterdam, 578 pp.
- ZEHNDER in STAUB, R. 1961. Ernährungphysiologish-autökologische Untersuchung an den planktonischen Blaualge Oscillatoria rubescens DC. Schweizerische Zeitschrift für Hydrologie 23: 82-198.
Dunaliella medium
Author: Schlösser 1982
The cultivation of halophilic algae.
Mix 20 ml of the stock macroelements solution with 910 ml of artificial seawater and 30 ml of seawater soil extract.
Component |
Stock Solution |
Quantity Used |
---|---|---|
KNO3 | 10,00 g | 10 ml |
K2HPO4 | 1,00 g | 10 ml |
MgSO4.7H2O | 1,00 g | 10 ml |
soil extract | see following recipe | 30 ml |
artificial seawater | see following recipe | 930 ml |
Soil extract
1/3 of 6 litre flask fill with garden or leaf soil (not too great humus or clay content), and deionized water until it stands 5cm above the soil. Sterilize by heating in a steamer one hour, twice in a 24h interval. Separate the decanted extract by centrifugation. Fill into small containers, autoclave 20 minutes/1 atmosphere; store in refrigerator.
Artificial seawater
Component |
Quantity Used |
---|---|
NaCl | 30,0 g |
MgSO4.7H2O | 31,0 g |
KCl | 1,5 g |
CaSO4 | 2,0 g |
Literature:
- Andersen, R.A. [ed.] 2005. Algal culturing techniques. Elsevier, Amsterdam, 578 pp.
- Schlösser, U.G., 1982. Sammlung von Algenkulturen. - Ber.Dt.bot.Ges. 95: 181-276.
Czurda medium
The receipt is not awailable at this moment
Spirulina medium
Authors: Aiba and Ogawa 1977, Schlösser 1994
For culturing Spirulina.
Prepare Solutions I and II. Autoclave separately and cool; asepticilly combine the two solutions. Aseptically add 1 ml of cyanocobalamin (B12) solution.
Component |
Stock Solution |
Quantity Used |
---|---|---|
Solution I. (500 ml) | ||
NaHCO3 | - | 13,61 g |
Na2CO3 | - | 4,03 g |
K2HPO4 | - | 0,50 g |
Solution II. (500 ml) | ||
NaNO3 | - | 2,5 g |
K2SO4 | - | 1,0 g |
NaCl | - | 1,0 g |
MgSO4.7H2O | - | 0,2 g |
CaCl2.2H2O | - | 0,04 g |
FeSO4.7H2O | - | 0,01 g |
Na2EDTA.2H2O | - | 0,08 g |
Trace metals solution | see following recipe | 5 ml |
Vitamins solution | see following recipe | 1 ml |
Trace metals solution
Component |
Stock Solution |
Quantity Used |
---|---|---|
Na2EDTA.2H2O | - | 0,5 g |
FeSO4.7H2O | - | 0,7 g |
ZnSO4.7H2O | 1,0 | 1 ml |
MnSO4.7H2O | 2,0 | 1 ml |
H3BO3 | 10,0 | 1 ml |
Co(NO3)2.6H2O | 1,0 | 1 ml |
Na2MoO4.2H2O | 1,0 | 1 ml |
CuSO4.5H2O | 0,005 | 1 ml |
Vitamin Solution
Dissolve the cyanocobalamin in 1 liter dH2O. Filter-sterilize and store frozen.
Component |
Quantity Used |
---|---|
Cyanocobalamin (vit. B12) | 5 mg |
Literauture:
- AIBA, S., and OGAWA, T. 1977. Assessment of growth yield of a blue-green alga:Spirulina platensis in axenic and continuous cultur. J. Gen. Microbiol. 102: 179 - 182.
- ANDERSEN, R.A. [ed.] 2005. Algal culturing techniques. Elsevier, Amsterdam, 578 pp.
- SCHLÖSSER, U.G. 1994. SAG-Sammlung von Algenkulturen at the University of Göttingen Catalogue of Strains 1994. Bot. Acta 107: 111 - 186.
Jaworski’s Medium
Author: Schlösser 1982
For freshwater algae.
Dissolve stock solutions 1 - 9 (1 ml each) in 1 litre of distilled water.
Component |
Stock Solution |
Quantity Used |
---|---|---|
Ca(NO3)2.4H2O | 20,0 | 1 ml |
KH2PO4 | 12,4 | 1 ml |
MgSO4.7H2O | 50,0 | 1 ml |
NaHCO3 | 15,9 | 1 ml |
EDTA solution | see following recipe | 1 ml |
Trace metals solution | see following recipe | 1 ml |
NaNO3 | 80,0 | 1 ml |
Na2HPO4.12H2O | 36,0 | 1 ml |
Vitamin solution | see following recipe | 1 ml |
EDTA-solution
Component |
Quantity Used |
---|---|
FeNa-EDTA | 0,45 g |
Na2EDTA | 0,45 g |
Trace metals solution
Component |
Quantity Used |
---|---|
H3BO3 | 0,496 g |
MnCl2.4H2O | 0,278 g |
(NH4)6Mo7O24.4H2O | 0,20 g |
Vitamins solution
Component |
Quantity Used |
---|---|
cyanocobalamin | 0,008 g |
thiamine HCl | 0,008 g |
biotin | 0,008 g |
Literature:
- ANDERSEN, R.A. [ed.] 2005. Algal culturing techniques. Elsevier, Amsterdam, 578 pp.
- SCHLÖSSER, U.G., 1982. Sammlung von Algenkulturen. - Ber.Dt.bot.Ges. 95: 181-276.
WC medium
Authors: Guillard & Lorenzen, 1972
For planktonic algae and cyanobacteria.
Combine 1 ml of stock solution and add TRIS buffer. Autoclave. Add sterille vitamin solution do cool medium.
Component | Stock Solution | Quantity Used |
---|---|---|
CaCl2.2H2O | 36,8 g | 1 ml |
MgSO4.7H2O | 37,0 g | 1 ml |
NaHCO3 | 12,6 g | 1 ml |
K2HPO4.3H2O | 5,7 g | 1 ml |
NaNO3 | 42,5 g | 1 ml |
Na2SiO3.5H2O | 21, 2 g | 1 ml |
trace metal solution | see bellow | 1 ml |
vitamins solution | see bellow | 1 ml |
TRIS | - | 0,115 g |
Trace metals solution
Component | Quantity Used |
---|---|
Na2EDTA | 4,360 g |
FeCl3.6H2O | 3,150 g |
CuSO4.5H2O | 0,010 g |
ZnSO4.7H2O | 0,022 g |
CoCl2.6H2O | 0,010 g |
MnCl2.4H2O | 0,180 g |
Na2MoO4.2H2O | 0,006 g |
H3BO3 | 1,000 g |
Vitamins solution
Sterile by filtration
Component | Quantity Used |
---|---|
thiamin | 0,1 g |
biotin | 0,0005 g |
cyanokabalamin | 0,0005 g |
Literature:
- GUILLARD, R.R.L., LORENZEN, C.J. (1972): Yellow-green algae with chlorophyllide C. Journal of Phycology 8: 10-14
Porphyridium medium
Authors: Brody & Emerson 1959, modif. Pekárková (pers. comm.)
Mix Solution 1 with 0,5 ml of Solution 2 and 0,5 ml of Solution 3 and autoclave.
Solution 1.
Component |
Quantity Used |
---|---|
KCl | 4,00 g |
NaCl | 3,13 g |
KNO3 | 1,24 g |
MgSO4.7H2O | 2,50 g |
K2HPO4 | 0,66 g |
Ca(NO3)2.4H2O | 0,17 g |
KI | 0,05 g |
KBr | 0,05 g |
Solution 2.
Component |
Quantity Used |
---|---|
Fe-EDTA | 4,6 g |
Solution 3.
Component |
Quantity Used |
---|---|
H3BO3 | 3,09 mg |
MnSO4.4H2O | 1,20 mg |
CoSO4.7H2O | 1,40 mg |
CuSO4.5H2O | 1,24 mg |
ZnSO4.7H2O | 1,43 mg |
(NH4)6Mo7O24.4H2O | 1,84 mg |
Literature:
- BRODY,M. & EMERSON,R. (1959): The effect of wavelength and intensity of light on the proportion of pigments in Porphyridium cruentum. - Am.J.Bot. 46: 433-440.
Euglena medium
Suitable for most axenic cultures of Euglena and Chlorogonium.
To approximately 950 ml of dH2O, add each of the components in the order specified while stirring continuously.
Bring the total volume to 1 l with dH2O.
Component |
Quantity Used |
---|---|
Na-acetate | 1 g |
Beef extract | 1 g |
Tryptone | 2 g |
Yeast extract | 2 g |
CaCl2.2H2O | 0,01 g |
Literature:
- ANDERSEN, R.A. [ed.] 2005. Algal culturing techniques. Elsevier, Amsterdam, 578 pp.
Brackish water
Component |
Stock Solution |
Quantity Used |
---|---|---|
KNO3 | 1,00 | 20 ml |
K2HPO4 | 0,1 g | 20 ml |
MgSO4.7H2O | 0,1 g | 20 ml |
Soil extract | see following recipe | 30 ml |
Trace metal solution | see following recipe | 5 ml |
dH2O | - | 450 ml |
Artificial seawater | see following recipe | 450 ml |
Soil extract
1/3 of 6 litre flask fill with garden or leaf soil (not too great humus or clay content), and deionized water until it stands 5cm above the soil. Sterilize by heating in a steamer one hour, twice in a 24h interval. Separate the decanted extract by centrifugation. Fill into small containers, autoclave 20 minutes/1 atmosphere; store in refrigerator.
Trace metals solution
Component |
Quantity Used |
---|---|
ZnSO4.7H2O | 8,82 g |
MnCl2.4H2O | 1,44 g |
MoO3 | 0,71 g |
CuSO4.5H2O | 1,57 g |
Co(NO3)2.6H2O | 0,49 g |
Artificial seawater
Component |
Quantity Used |
---|---|
NaCl | 30,0 g |
MgSO4.7H2O | 10,0 g |
KCl | 1,5 g |
CaSO4.2H2O | 2,0 g |
MASM
The receipt is not awailable at this moment
1/2 SŠ medium
Authors: Zachleder & Šetlík, 1982
Combine 970 ml of dH2O and 10 ml of each stock solution. Autoclave. After cooling add 1,5 ml of 1N NaOH (=10g NaOH in 250 ml of dH2O.
For Euhalothece add 100g of Na2CO3 to 1 litre of medium.
Component |
Stock Solution |
Quantity Used |
---|---|---|
Stock solution 1. |
||
MgSO4.7H2O | 98,8 g | 10 ml |
Trace metals elements (see following recipe) | 100 ml | |
Stock solution 2. |
||
KNO3 | 202,0 g | 10 ml |
CaCl2.6H2O | 1,1 g | |
Fe-EDTA | 1,8 g | |
Stock solution 3. |
||
KH2PO4 | 34,0 g | 10 ml |
Trace metals solution
Component |
Quantity Used |
---|---|
H3BO3 | 3,086 g |
MnSO4.4H2O | 1,18 g |
CoSO4.7H2O | 1,404 g |
CuSO4.5H2O | 1,244 g |
ZnSO4.7H2O | 1,43 g |
(MN4)6Mo7O24.4H2O | 1,84 g |
Literature:
- ZACHLEDER, V. & ŠETLÍK, I. 1982. Effect of Irradiance on the Course of RNA Synthesis in the Cell Cycle of Scenedesmus quadricauda. Biologia Plantarum 24(5): 341 - 353.
HS medium for Chlamydomonas
Author: Sueoka 1960
Into 500 ml of dH2O add quantity of stock solutions (see belowe) fill in 990 mililitre with dH2O. Autoclave. After cooling add 10 ml od stock solution no. 5.
Component |
Stock Solution |
Quantity Used |
---|---|---|
Stock stolution 1. |
||
NH4Cl | 50,00 | 10 ml |
CaCl2.2H2O | 2,00 | |
Stock solution 2. |
||
MgSO4.7H2O | 20,00 | 10 ml |
FeNa-EDTA | 1,84 | |
Stock solution 3. |
||
Na2MoO4.2H2O | 5,00 (or 0,5 g to 100 ml dH2O) | 0,5 ml |
Stock solution 4. |
||
Trace metals solution | see following recipe | 1 ml |
Stock solution 5. |
||
Add after autoclaving! | ||
KH2PO4 | 72,00 | 5 ml |
K2HPO4 | 134,00 |
Trace metals solution
Component |
Quantity Used |
---|---|
H3BO3 | 3,086 g |
MnSO4.4H2O | 1,180 g |
CoSO4.7H2O | 1,404 g |
CuSO4.5H2O | 1,244 g |
ZnSO4.7H2O | 1,430 g |
(NH4)6Mo7O24.4H2O | 1,840 g |
Literature:
- Sueoka, N. 1960. MITOTIC REPLICATION OF DEOXYRIBONUCLEIC ACID IN CHLAMYDOMONAS REINHARDI. PNAS 46(1): 83-91.
Medium for non-seed plants
Authors: Baslerová & Dvořáková 1962
Liverworts, ferns and duckweeds are maintained in 250 ml Erlenmayer's flasks on agar medium in the air conditioned room at 12-15°C. They are irradiated similarly as other strains (see above).
Into 900 ml of dH2O add quantity of stock solutions (see belowe) fill in 1 litre with dH2O. Autoclave.
Component |
Stock Solution |
Quantity Used | |
---|---|---|---|
Mosses (M) |
Liverworts & ferns (JKL) |
||
NH4NO3 | 80,00 | 1.5 ml | 2.5 ml |
KH2PO4 | 136,00 | 0.5 ml | 0.75 ml |
MgSO4.7H2O | 120,00 | 0.5 ml | 0.4 ml |
CaCl2.2H2O | 110,00 | 0.2 ml | 1,0 ml |
FeCl3.6H2O | 16.20 | 0.2 ml | 0.16 ml |
Literature:
- Baslerová, M. & Dvořáková, J. 1962. Algarum, Hepaticarum Muscurumque in cultiris collectio. NCSAV, Praha, 59 pp.
Gorham’s solution
Authors: Koeman & Hoek 1980
In 1000 ml distilled water dissolve the following chemicals and add 2 ml of soil extract.
Component |
Quantity Used |
---|---|
NaNO3 | 160 mg |
K2HPO4 | 17,5 mg |
TRIS buffer | 200 mg |
MgSO4.7H2O | 153,6 mg |
CuSO4.5H2O | 0,0156 mg |
CaCl2 | 35 mg |
Na2SiO3 | 11,63 mg |
Na2CO3 | 20 mg |
Fe-citrate | 3 mg |
Citric acid | 3 mg |
Na-EDTA (Chelaton III) | 600 mg |
Na2MoO4.2H2O | 0,00705 mg |
ZnSO4.7H2O | 0,0392 mg |
CoCl2 | 0,0183 mg |
MnCl2.4H2O | 0,283 mg |
Soil extract
1/3 of 6 litre flask fill with garden or leaf soil (not too great humus or clay content), and deionized water until it stands 5cm above the soil. Sterilize by heating in a steamer one hour, twice in a 24h interval. Separate the decanted extract by centrifugation. Fill into small containers, autoclave 20 minutes/1 atmosphere; store in refrigerator.
Literature:
- KOEMAN,R.P.T. & HOEK,C. van den (1980): The taxonomy of Ulva (Chlorophyceae) in the Netherland. - Brit.Phycol.J. 16: 9-53.
BBM medium
Authors: Bold 1949, Bischoff and Bold 1963
Useful for many algae, especially chlorococcalea algae, volvocalean algae (e.g.Chlamydomonas), filamentous green alga Klebsormidim flaccidum, xanthophycean alga Heterococcus endolithicus etc. (Andersen, 2005).
Into 900 ml of dH2O add 10 ml of first six stock solutions. Add 1 ml of rest solutions. Autoclave. The final pH should be 6,6
Component |
Stock Solution |
Quantity Used |
---|---|---|
NaNO3 | 25,00 | 10 ml |
CaCl2.2H2O | 2,50 | 10 ml |
MgSO4.7H2O | 7,50 | 10 ml |
K2HPO4 | 7,50 | 10 ml |
KH2PO4 | 17,50 | 10 ml |
NaCl | 2,50 | 10 ml |
EDTA solution | see following recipe | 1 ml |
Acidifed iron solution | see following recipe | 1 ml |
H3BO3 | 11,42 g | 1 ml |
Trace metals solution | see following recipe | 1 ml |
EDTA solution
Component |
Quantity Used |
---|---|
EDTA | 50,00 g |
KOH | 31,00 g |
Acidified Iron Solution
Component |
Quantity Used |
---|---|
FeSO4.7H2O | 0,498 g |
H2SO4 (96%) | 0,1 ml |
Trace metals solution
Component |
Quantity Used |
---|---|
ZnSO4.7H2O | 8,82 g |
MnCl2.4H2O | 1,44 g |
MoO3 | 0,71 g |
CuSO4.5H2O | 1,57 g |
Co(NO3)2.6H2O | 0,49 g |
Literature:
- ANDERSEN, R.A. [ed.] 2005. Algal culturing techniques. Elsevier, Amsterdam, 578 pp.
- BISCHOFF, H.W., and BOLD, H.C. 1963.Phycological Studies IV. Some Soil Algae From Enchanted Rock and Related Algal Specie. University of Texas, Austin, 6318: 1 - 95.
- BOLD, H.C. 1949. The morphology of Chlamydomonas chlamydogama sp. nov.. Bull. Torrey Bot. Club. 76: 101 - 108.
BG11 medium
Authors: Allen 1968, Allen and Stainer 1968, Rippka et al. 1979
For culture of freshwater, soil, thermal and marine cyanobacteria (Andersen, 2005).
Component |
Stock Solution |
Quantity Used |
---|---|---|
Fe-citrate solution | see following recipe | 1 ml |
NaNO3 | - | 1,5 g |
K2HPO4.3H3O | 40 | 1 ml |
MgSO4.7H2O | 75 | 1 ml |
CaCl2.2H2O | 35 | 1 ml |
Na2CO3 | 20 | 1 ml |
Na-EDTA | 1,0 | 1 ml |
Trace metals solution | see following recipe | 1 ml |
Fe-citrate solution
Component |
Stock Solution |
Quantity Used |
---|---|---|
Citric acid | 6 | 1 ml |
Ferric ammonium citrate | 6 | 1 ml |
Trace metals solution
Component |
Stock Solution |
Quantity Used |
---|---|---|
H3BO3 | - | 2,860 g |
MnCl2.4H2O | - | 1,810 g |
ZnSO4.7H2O | - | 0,220 g |
CuSO4.5H2O | 79,0 | 1 ml |
Na2MoO4.2H2O | - | 0,391 g |
Co(NO3)2.6H2O | 49,4 | 1 ml |
Literature:
- ALLEN, M.M. 1968. Simple conditions for growth of unicellular blue-green algae. J. Gen. Microbiol. 51: 199 - 202.
- ALLEN, M.M., and STAINER, R.Y. 1968. Studies with Cyanidium caldarium, an anomalously pigmented chlorophyte. Arch. Mikrobiol. 32: 270 - 277.
- ANDERSEN, R.A. [ed.] 2005. Algal culturing techniques. Elsevier, Amsterdam, 578 pp.
- RIPKA, R., DERUELLES, J., WATERBURY, J.B., HERDMAN, M., and STAINER, R.Y. 1979. Generic assignment, strain histories and properties of pure cultures of cyanobacteria. J. Gen. Microbiol. 111: 1 - 61.