ldm_medium

CultureMech:000173 algae COMPLEX LIQUID
Original name: LDM Medium

Overview

External ontology
UTEX:ldm-medium (source link unavailable) — LDM Medium
Applications
  • Algae cultivation
  • Phytoplankton culture
  • Microalgae research
Notes
UTEX prepares LDM Medium from 30 ppt seawater, Bristol-family macronutrient stocks at one-tenth strength, P-IV Metal Solution, Tryptone, Vitamin B12, and Biotin Vitamin Solution.

Composition

flowchart LR
    CultureMech_000173["ldm_medium"]
    ing0_Seawater__30_ppt_["Seawater (30 ppt)"]
    CultureMech_000173 --> ing0_Seawater__30_ppt_
    ing1_NaNO3["NaNO3"]
    CultureMech_000173 --> ing1_NaNO3
    CHEBI_63005["CHEBI:63005"]
    ing1_NaNO3 -.-> CHEBI_63005
    ing2_CaCl2_x_2_H2O["CaCl2 x 2 H2O"]
    CultureMech_000173 --> ing2_CaCl2_x_2_H2O
    CHEBI_86158["CHEBI:86158"]
    ing2_CaCl2_x_2_H2O -.-> CHEBI_86158
    ing3_MgSO4_x_7_H2O["MgSO4 x 7 H2O"]
    CultureMech_000173 --> ing3_MgSO4_x_7_H2O
    CHEBI_31795["CHEBI:31795"]
    ing3_MgSO4_x_7_H2O -.-> CHEBI_31795
    ing4_K2HPO4["K2HPO4"]
    CultureMech_000173 --> ing4_K2HPO4
    CHEBI_131527["CHEBI:131527"]
    ing4_K2HPO4 -.-> CHEBI_131527
    ing5_KH2PO4["KH2PO4"]
    CultureMech_000173 --> ing5_KH2PO4
    CHEBI_63036["CHEBI:63036"]
    ing5_KH2PO4 -.-> CHEBI_63036
    ing6_NaCl["NaCl"]
    CultureMech_000173 --> ing6_NaCl
    CHEBI_26710["CHEBI:26710"]
    ing6_NaCl -.-> CHEBI_26710
    ing7_Tryptone["Tryptone"]
    CultureMech_000173 --> ing7_Tryptone

Ingredients (8)

# Ingredient Concentration Ontology Notes
1 Seawater (30 ppt) 1000 ML_PER_L ENVO:00002149
sea water
 UTEX starts with 950 mL and brings LDM Medium to 1 L with seawater at 30 ppt.
2 NaNO3
NO3.Na 84.994 g/mol
Fisher BP360-500
0.29 MILLIMOLAR CHEBI:63005
sodium nitrate
 UTEX adds 1 mL/L of a 10 g/400 mL dH2O stock, for 0.29 mM final.
3 CaCl2 x 2 H2O
Ca.2Cl.2H2O 147.014 g/mol
Sigma C-3881
0.017 MILLIMOLAR CHEBI:86158
calcium chloride dihydrate
 UTEX adds 1 mL/L of a 1 g/400 mL dH2O stock, for 0.017 mM final.
4 MgSO4 x 7 H2O
7H2O.Mg.O4S 246.473 g/mol
Sigma 230391
0.03 MILLIMOLAR CHEBI:31795
magnesium sulfate heptahydrate
 UTEX adds 1 mL/L of a 3 g/400 mL dH2O stock, for 0.03 mM final.
5 K2HPO4
HO4P.2K 174.174 g/mol
Sigma P 3786
0.043 MILLIMOLAR CHEBI:131527
dipotassium hydrogen phosphate
 UTEX adds 1 mL/L of a 3 g/400 mL dH2O stock, for 0.043 mM final.
6 KH2PO4
H2O4P.K 136.084 g/mol
Sigma P 0662
0.129 MILLIMOLAR CHEBI:63036
potassium dihydrogen phosphate
 UTEX adds 1 mL/L of a 7 g/400 mL dH2O stock, for 0.129 mM final.
7 NaCl
Cl.Na 58.443 g/mol
Fisher S271-500
0.043 MILLIMOLAR CHEBI:26710
sodium chloride
 UTEX adds 1 mL/L of a 1 g/400 mL dH2O stock, for 0.043 mM final.
8 Tryptone
Sigma T 9410
1 G_PER_L MICRO:0000182 (source link unavailable)
Tryptone
 UTEX lists 1 g/L Tryptone, Sigma T 9410.

Preparation

  1. To approximately 950 mL seawater at 30 ppt, add each component except vitamins in the order specified while stirring continuously.
  2. Bring the total volume to 1 L with non-pasteurized seawater.
  3. Cover and autoclave the medium.
  4. Allow the medium to cool, then add sterile vitamins.
  5. Store at refrigerator temperature.

Solutions

P-IV Metal Solution

Dose: 6 ML_PER_L

Stock composition
IngredientConcentrationNotes
dH2O 1000 ML_PER_L UTEX brings P-IV Metal Solution to 1 L with dH2O.
Na2EDTA x 2 H2O 0.75 G_PER_L UTEX lists 0.75 g/L Na2EDTA x 2 H2O, 2 mM final, and dissolves it fully before the other P-IV components.
FeCl3 x 6 H2O 0.097 G_PER_L UTEX lists 0.097 g/L FeCl3 x 6 H2O, for 0.36 mM final.
MnCl2 x 4 H2O 0.041 G_PER_L UTEX lists 0.041 g/L MnCl2 x 4 H2O, for 0.21 mM final.
ZnCl2 0.005 G_PER_L UTEX lists 0.005 g/L ZnCl2, for 0.037 mM final.
CoCl2 x 6 H2O 0.002 G_PER_L UTEX lists 0.002 g/L CoCl2 x 6 H2O, for 0.0084 mM final.
Na2MoO4 x 2 H2O 0.004 G_PER_L UTEX lists 0.004 g/L Na2MoO4 x 2 H2O, for 0.017 mM final.
UTEX adds 6 mL P-IV Metal Solution per liter.

Vitamin B12

Dose: 1 ML_PER_L

Stock composition
IngredientConcentrationNotes
dH2O 1000 ML_PER_L UTEX prepares the Vitamin B12 stock in 200 mL HEPES buffer.
HEPES buffer pH 7.8 12 G_PER_L Converted from 2.4 g/200 mL in the UTEX Vitamin B12 stock.
Vitamin B12 0.135 G_PER_L Converted from 0.027 g/200 mL in the UTEX Vitamin B12 stock.
UTEX adds 1 mL Vitamin B12 stock per liter.

Biotin Vitamin Solution

Dose: 1 ML_PER_L

Stock composition
IngredientConcentrationNotes
dH2O 1000 ML_PER_L UTEX prepares the biotin stock in 200 mL HEPES buffer.
HEPES buffer pH 7.8 12 G_PER_L Converted from 2.4 g/200 mL in the UTEX biotin stock.
Biotin 0.025 G_PER_L Converted from 0.005 g/200 mL in the UTEX biotin stock.
UTEX adds 1 mL Biotin Vitamin Solution per liter.

Target organisms

No target organisms are recorded.

Provenance

TimestampCuratorActionNotes
2026-01-28T00:00:00+00:00 utex-import Imported from UTEX Culture Collection Source ID: ldm-medium, URL: https://utex.org/products/ldm-medium
2026-03-13T06:18:53.412786Z culturemech-id-assigner-v1.0 Assigned CultureMech ID Assigned stable identifier: CultureMech:000173
2026-03-17T19:45:04.348280+00:00 normalize_media_names_to_snake_case.py NAME_NORMALIZED Normalized name from "LDM Medium" to "ldm_medium" for consistent matching
2026-05-16T09:02:56.021070+00:00 migrate_legacy_fields.py MIGRATED_LEGACY_FIELDS curation_history.date->timestamp=1; references.reference_id->reference=2; category->lowercase=1
2026-05-16T09:11:01.225356+00:00 migrate_preparation_steps.py MIGRATED_PREPARATION_STEPS instruction->action+description for 9 step(s)
2026-08-30T00:58:30.841457+00:00 repair_utex_ingredients.py REPAIRED_UTEX_COMPOSITION Restored 11 ingredient name(s) and amount(s) from a re-fetched UTEX capture. The original fetcher read fixed column positions, so the row ordinal was stored as the ingredient name, the component name as the amount, and the Amount column was never read; concentration was then filled in as G_PER_L regardless. Source: https://utex.org/pages/algal-culture-media, captured 2026-08-29T17:46:40.207779.
2026-09-06T00:00:00-07:00 repair_utex_modified_ldm_score35.py RESOLVED_UTEX_MODIFIED_LDM_SCORE35 UTEX prepares LDM Medium from 30 ppt seawater, Bristol-family macronutrient stocks at one-tenth strength, P-IV Metal Solution, Tryptone, Vitamin B12, and Biotin Vitamin Solution.