Overview
- Applications
-
- Algae cultivation
- Phytoplankton culture
- Microalgae research
- Notes
- Full recipe available at http://sagdb.uni-goettingen.de/culture_media/19 Z-Medium for Cyanos.pdf Composition verified against https://sagdb.uni-goettingen.de/culture_media/19%20Z-Medium%20for%20Cyanos.pdf on 2026-08-25 (SHA-256 4a1c1aa967637b9212a814bd01ebffa554338105e8c1a1bee7d03a93cd07b6d6).
Composition
flowchart LR
CultureMech_000218["z_medium_for_cyanos"]
ing0_NaNO3["NaNO3"]
CultureMech_000218 --> ing0_NaNO3
CHEBI_63005["CHEBI:63005"]
ing0_NaNO3 -.-> CHEBI_63005
ing1_Ca_NO3_2_x_4_H2O["Ca(NO3)2 x 4 H2O"]
CultureMech_000218 --> ing1_Ca_NO3_2_x_4_H2O
CHEBI_86159["CHEBI:86159"]
ing1_Ca_NO3_2_x_4_H2O -.-> CHEBI_86159
ing2_K2HPO4["K2HPO4"]
CultureMech_000218 --> ing2_K2HPO4
CHEBI_131527["CHEBI:131527"]
ing2_K2HPO4 -.-> CHEBI_131527
ing3_MgSO4_x_7_H2O["MgSO4 x 7 H2O"]
CultureMech_000218 --> ing3_MgSO4_x_7_H2O
CHEBI_31795["CHEBI:31795"]
ing3_MgSO4_x_7_H2O -.-> CHEBI_31795
ing4_Na2CO3["Na2CO3"]
CultureMech_000218 --> ing4_Na2CO3
CHEBI_29377["CHEBI:29377"]
ing4_Na2CO3 -.-> CHEBI_29377
ing5_Deionized_or_distilled_water["Deionized or distilled water"]
CultureMech_000218 --> ing5_Deionized_or_distilled_water
CHEBI_15377["CHEBI:15377"]
ing5_Deionized_or_distilled_water -.-> CHEBI_15377
Ingredients (6)
| # | Ingredient | Concentration | Ontology | Notes |
|---|---|---|---|---|
| 1 |
NaNO3
NO3.Na 84.994 g/mol
|
467.0 MG_PER_L |
CHEBI:63005
sodium nitrate
|
|
| 2 |
Ca(NO3)2 x 4 H2O
Ca.4H2O.2NO3 236.146 g/mol
|
59.0 MG_PER_L |
CHEBI:86159
calcium nitrate tetrahydrate
|
|
| 3 |
K2HPO4
HO4P.2K 174.174 g/mol
|
31.0 MG_PER_L |
CHEBI:131527
dipotassium hydrogen phosphate
|
|
| 4 |
MgSO4 x 7 H2O
7H2O.Mg.O4S 246.473 g/mol
|
25.0 MG_PER_L |
CHEBI:31795
magnesium sulfate heptahydrate
|
The source prints H20; interpreted as the heptahydrate used throughout the SAG recipes. |
| 5 |
Na2CO3
CO3.2Na 105.988 g/mol
|
21.0 MG_PER_L |
CHEBI:29377
sodium carbonate
|
|
| 6 |
Deionized or distilled water
H2O 18.015 g/mol
|
1 L |
CHEBI:15377
water
|
Preparation
- Prepare the stock solutions and combine them at the stated amounts.
- Autoclave at 121 C for 15 minutes following the SAG general preparation guidance.
- The nitrogen-free Z 45/4 variant is listed separately and is not asserted here.
Solutions
Z-medium Fe-EDTA complex
Dose: 10.0 ML_PER_L
| Ingredient | Concentration | Notes |
|---|---|---|
| FeCl2 x 6 H2O | 0.27 G_PER_L | |
| Disodium EDTA | 0.372 G_PER_L | The source specifies the disodium salt without a hydration state. |
| Deionized or distilled water | 1 L |
Calculated from 5 mL each of source primary stocks (27 and 37.2 g/L) made to 500 mL.
Z-medium micronutrient solution
Dose: 0.08 ML_PER_L
| Ingredient | Concentration | Notes |
|---|---|---|
| H3BO3 | 3100 MG_PER_L | |
| MnSO4 x 4 H2O | 2230 MG_PER_L | |
| Na2WO4 x 2 H2O | 33 MG_PER_L | |
| (NH4)6Mo7O24 x 4 H2O | 88 MG_PER_L | |
| KBr | 119 MG_PER_L | |
| KI | 83 MG_PER_L | The PDF prints KJ; interpreted as potassium iodide from the formula context. |
| ZnSO4 x 7 H2O | 287 MG_PER_L | |
| Cd(NO3)2 x 4 H2O | 154 MG_PER_L | |
| Co(NO3)2 x 6 H2O | 146 MG_PER_L | |
| CuSO4 x 5 H2O | 125 MG_PER_L | |
| NiSO4(NH4)2SO4 x 6 H2O | 198 MG_PER_L | No exact MediaIngredientMech SSSOM mapping was available. |
| Cr(NO3)3 x 7 H2O | 37 MG_PER_L | |
| VOSO4 x 2 H2O | 20 MG_PER_L | |
| Al2(SO4)3K2SO4 x 24 H2O | 474 MG_PER_L | No exact MediaIngredientMech SSSOM mapping was available. |
| Deionized or distilled water | 1 L |
Source amounts per 100 mL were normalized to concentrations per litre.
Target organisms
No target organisms are recorded.
Provenance
| Timestamp | Curator | Action | Notes |
|---|---|---|---|
| 2026-01-28T00:00:00+00:00 | sag-import | Imported from SAG Culture Collection | Source ID: Z-Medium_for_Cyanos, PDF URL: http://sagdb.uni-goettingen.de/culture_media/19 Z-Medium for Cyanos.pdf |
| 2026-02-03T00:00:00+00:00 | schema-defaulter-v1.0 | Applied schema defaults and normalizations | Added placeholder ingredients for missing composition |
| 2026-02-03T11:26:43.812617 | quality-tagger-v1.0 | Added data quality flag | Marked as incomplete_composition due to placeholder ingredients |
| 2026-03-13T06:18:53.583676Z | culturemech-id-assigner-v1.0 | Assigned CultureMech ID | Assigned stable identifier: CultureMech:000218 |
| 2026-03-17T19:45:04.506245+00:00 | normalize_media_names_to_snake_case.py | NAME_NORMALIZED | Normalized name from "Z-Medium_for_Cyanos" to "z_medium_for_cyanos" for consistent matching |
| 2026-05-16T09:02:57.151009+00:00 | migrate_legacy_fields.py | MIGRATED_LEGACY_FIELDS | curation_history.date->timestamp=2; references.reference_id->reference=2; category->lowercase=1 |
| 2026-08-06T07:56:36.069058+00:00 | curate_placeholder_composition.py | REMOVED_PLACEHOLDER_INGREDIENT | Removed the 'See source for composition' placeholder ingredient; the record carries no imported composition and is flagged incomplete (#175). |
| 2026-08-25T00:00:00-07:00 | repair_sag_missing_compositions.py | RESTORED_SAG_SOURCE_COMPOSITION | Restored the formulation from the reviewed SAG PDF, preserving final-medium and stock-solution boundaries. Calculated stock concentrations are documented in-place. Ingredient identities were selected from the MediaIngredientMech SSSOM. |
| 2026-09-07T00:00:00-07:00 | repair_sag_missing_compositions.py | TAGGED_SAG_RESTORED_COMPOSITION_CURATED | Marked the reviewed SAG source formulation as curated and ontology-mapped after the original restoration left only the ingredient identities and did not add the scoring flags. |
| 2026-09-13T00:00:00-07:00 | repair_sag_sources_score10.py | NORMALIZED_SAG_SOURCE_SCORE10 | Copied the SAG source identity from references and the original sag-import event into the structured sources slot recognized by review scoring. |