1/4 Soil+Seawater Medium
For some marine and brackish-water algae requiring salinities at 7.5 ppt, glass-distilled water and pasteurized, filtered seawater are combined prior to steaming, such that 1/4 Soil+Seawater contains seawater combined with distilled water 1:3.
Directions
For 200 mL Total
- Combine all components.
- Cover the medium container and steam for 2 consecutive days, 3 hours on each day. Pasteurization is a gradual rising of temperature to approximately 95 °C in 15 minutes. Then increased just over 98 °C for the 3 hour duration. Cooling occurs gradually at room temperature.
- Refrigerate 24 hours or more and bring to room temperature before using.
| # | Component | Amount | Stock Solution Concentration | Final Concentration |
|---|---|---|---|---|
| 1 | Green House Soil | 1 tsp | ||
| 2 | CaCO3 (optional) (Fisher C 64) | 1 mg | 0.05 mM | |
| 3 | Pasteurized Seawater | 50 mL | ||
| 4 | dH2O | 150 mL |
Important Notes To Consider:
- The quality of water, including natural seawater, is important. The term 'dH2O' generally refers to distilled, deionized, distilled/deionized water, Milli-Q water (Millipore Corp.), etc. Natural seawater and natural freshwater should be obtained from a non-polluted source.
- When dissolving chemicals, wait for the first component to dissolve before adding the second. Stirring, and sometimes the addition of heat, is often required to dissolve the chemicals efficiently. Preparation of stock solutions for frequently made algal culture media make preparing media convenient but also necessary to avoid errors from weighing very tiny amounts.
- Attention should be given to the pH of the final medium. In most cases, if pH adjustment is required, this occurs before sterilization. Please note that autoclaving removes carbon dioxide from media lacking carbonate stabilizing buffers. This would make the medium very alkaline soon after removal from the autoclave. In these cases, you should wait approximately 24 hours for gaseous equilibrium before inoculating the medium.
Additional algal culture media recipes can be found at the following other major Collections' websites:
- Culture Collection of Algae and Protozoa (CCAP)
- National Center for Marine Algae and Microbiota (NCMA)
- National Institute for Environmental Studies (NIES) Microbial Culture Collection
- The Pasteur Culture Collection of Cyanobacteria (PCC)
- The Culture Collection of Algae at Goettingen University (SAG)
- Canadian Phycological Culture Centre (CPCC)
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