bold_basal_medium (CultureMech:000034)

Overview

External ontology

UTEX:bold-basal-medium (source link unavailable) — Bold Basal Medium

Applications

Algae cultivation
Phytoplankton culture
Microalgae research

Notes

UTEX prepares Bold Basal Medium from the six Bristol mineral stocks plus one drop each of BBM EDTA, Iron, Boron, and Bold Trace stocks.

Composition

flowchart LR
    CultureMech_000034["bold_basal_medium"]
    ing0_dH2O["dH2O"]
    CultureMech_000034 --> ing0_dH2O
    CHEBI_15377["CHEBI:15377"]
    ing0_dH2O -.-> CHEBI_15377
    ing1_NaNO3["NaNO3"]
    CultureMech_000034 --> ing1_NaNO3
    CHEBI_63005["CHEBI:63005"]
    ing1_NaNO3 -.-> CHEBI_63005
    ing2_CaCl2_x_2_H2O["CaCl2 x 2 H2O"]
    CultureMech_000034 --> 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_000034 --> ing3_MgSO4_x_7_H2O
    CHEBI_31795["CHEBI:31795"]
    ing3_MgSO4_x_7_H2O -.-> CHEBI_31795
    ing4_K2HPO4["K2HPO4"]
    CultureMech_000034 --> ing4_K2HPO4
    CHEBI_131527["CHEBI:131527"]
    ing4_K2HPO4 -.-> CHEBI_131527
    ing5_KH2PO4["KH2PO4"]
    CultureMech_000034 --> ing5_KH2PO4
    CHEBI_63036["CHEBI:63036"]
    ing5_KH2PO4 -.-> CHEBI_63036
    ing6_NaCl["NaCl"]
    CultureMech_000034 --> ing6_NaCl
    CHEBI_26710["CHEBI:26710"]
    ing6_NaCl -.-> CHEBI_26710

Ingredients (7)

#	Ingredient	Concentration	Ontology	Notes
1	dH2O H2O 18.015 g/mol		CHEBI:15377 water	UTEX starts the 1 L Bold Basal Medium recipe with approximately 900 mL dH2O.
2	NaNO3 NO3.Na 84.994 g/mol Fisher BP360-500	2.94 MILLIMOLAR	CHEBI:63005 sodium nitrate	UTEX adds 10 mL/L of a 10 g/400 mL dH2O stock, for 2.94 mM final.
3	CaCl2 x 2 H2O Ca.2Cl.2H2O 147.014 g/mol Sigma C-3881	0.17 MILLIMOLAR	CHEBI:86158 calcium chloride dihydrate	UTEX adds 10 mL/L of a 1 g/400 mL dH2O stock, for 0.17 mM final.
4	MgSO4 x 7 H2O 7H2O.Mg.O4S 246.473 g/mol Sigma 230391	0.3 MILLIMOLAR	CHEBI:31795 magnesium sulfate heptahydrate	UTEX adds 10 mL/L of a 3 g/400 mL dH2O stock, for 0.3 mM final.
5	K2HPO4 HO4P.2K 174.174 g/mol Sigma P 3786	0.43 MILLIMOLAR	CHEBI:131527 dipotassium hydrogen phosphate	UTEX adds 10 mL/L of a 3 g/400 mL dH2O stock, for 0.43 mM final.
6	KH2PO4 H2O4P.K 136.084 g/mol Sigma P 0662	1.29 MILLIMOLAR	CHEBI:63036 potassium dihydrogen phosphate	UTEX adds 10 mL/L of a 7 g/400 mL dH2O stock, for 1.29 mM final.
7	NaCl Cl.Na 58.443 g/mol Fisher S271-500	0.43 MILLIMOLAR	CHEBI:26710 sodium chloride	UTEX adds 10 mL/L of a 1 g/400 mL dH2O stock, for 0.43 mM final.

Preparation

To approximately 900 mL dH2O, add the six Bristol mineral stocks and one drop each of EDTA, Iron, Boron, and Bold Trace stocks.
Bring the total volume to 1 L with dH2O.
Transfer the medium to a 2 L Erlenmeyer flask and cover.
Autoclave the covered Bold Basal Medium.

Solutions

EDTA Stock

Dose: 0.05 ML_PER_L

Stock composition
Ingredient	Concentration	Notes
dH2O		UTEX brings BBM EDTA Stock Solution to 1 L with dH2O.
EDTA	50 G_PER_L	UTEX lists 50 g EDTA acid form per liter.
KOH	31 G_PER_L	UTEX lists 31 g KOH per liter.

UTEX adds one approximately 0.05 mL drop per liter of Bold Basal Medium.

Iron Stock

Dose: 0.05 ML_PER_L

Stock composition
Ingredient	Concentration	Notes
dH2O		UTEX brings BBM Iron Stock Solution to 1 L with dH2O.
H2SO4	10 ML_PER_L	UTEX adds 10 mL H2SO4 and makes this iron stock up to 1 L. The inspected HTML and PDF do not specify acid strength; no density or molarity conversion is assumed.
FeSO4 x 7 H2O	5 G_PER_L	UTEX lists 5 g FeSO4 x 7 H2O per liter.

UTEX adds one approximately 0.05 mL drop per liter of Bold Basal Medium.

Boron Stock

Dose: 0.05 ML_PER_L

Stock composition
Ingredient	Concentration	Notes
dH2O		UTEX brings BBM Boron Stock Solution to 1 L with dH2O.
H3BO3	11 G_PER_L	UTEX lists 11 g H3BO3 per liter.

UTEX adds one approximately 0.05 mL drop per liter of Bold Basal Medium.

Bold Trace Stock

Dose: 0.05 ML_PER_L

Stock composition
Ingredient	Concentration	Notes
dH2O		UTEX brings BBM Bold Trace Stock Solution to 1 L with dH2O.
H2SO4	10 ML_PER_L	UTEX lists 10 mL concentrated H2SO4 per liter.
ZnSO4 x 7 H2O	8.82 G_PER_L	UTEX lists 8.82 g ZnSO4 x 7 H2O per liter.
MnCl2 x 4 H2O	1.44 G_PER_L	UTEX prints MnCl with tetrahydrate in this stock row, without the second chloride. The existing MnCl2 identity and 1.44 g/L amount are retained unverified; no final-medium conversion is made.
MoO3	0.71 G_PER_L	UTEX lists 0.71 g MoO3 per liter.
CuSO4 x 5 H2O	1.57 G_PER_L	UTEX lists 1.57 g CuSO4 x 5 H2O per liter.
Co(NO3)2 x 6 H2O	0.49 G_PER_L	UTEX lists 0.49 g Co(NO3)2 x 6 H2O per liter.

UTEX adds one approximately 0.05 mL drop per liter of Bold Basal Medium.

Target organisms and growth evidence

These are curated observations and conditions for named organisms; they do not imply universal growth suitability.

Preferred term
Scenedesmus quadricauda
Term
Id
NCBITaxon:3089
Label
Scenedesmus quadricauda
Strain
CPCC-158
Growth metrics
- Measurement conditions
  BBM culture in aerated 250 mL Erlenmeyer flasks during an 11-day 17β-estradiol exposure experiment; pH was adjusted to 7.0.
  Evidence
  Reference
  PMID:35807621
  Supports
  SUPPORT
  Snippet
  E2 promoted the growth of S. quadricauda and L. minor
  Explanation
  The source reports Scenedesmus quadricauda growth responses in BBM-based experimental cultures.
Evidence
- Reference
  PMID:35807621
  Supports
  SUPPORT
  Snippet
  Scenedesmus quadricauda (CPCC-158)
  Explanation
  Kozlova and Levin used Scenedesmus quadricauda CPCC-158 in BBM and measured algal cell-density growth over an 11-day experiment.

Recipe variants

Name
bbm_estradiol_exposure_assay
Description
Study-specific BBM stock-culture and estradiol assay conditions. The study cites Stein 1973 for BBM; exact equivalence to this UTEX parent formulation is not established.
Modifications
- Adjust pH to 7.0 before use.
- Aerate 250 mL Erlenmeyer flask cultures during the 11-day experiment.
- Test separate 17-beta-estradiol treatments at 0.25, 0.75, 2.50, 5.0 and 15.0 ng/L, with a no-hormone control.
- Maintain the pre-experiment Scenedesmus quadricauda stock culture in modified BBM containing 4.5 ppm NH4Cl; do not assert this as a universal final assay-medium dose.
Purpose
Experimental hormone-exposure growth assay using BBM as the base medium.
Evidence
- Reference
  PMID:35807621
  Supports
  SUPPORT
  Snippet
  The study was conducted using three types of media: Bold Basal Medium (BBM)
  Explanation
  The paper explicitly used BBM as one of three media for the Scenedesmus quadricauda CPCC-158 growth experiment.
- Reference
  doi:10.3390/plants11131669
  Supports
  SUPPORT
  Snippet
  0.25, 0.75, 2.50, 5.0, and 15.0 ng/L
  Explanation
  variants[0].modifications[0:4]: the listed E2 levels are discrete active-estradiol concentrations, with a no-hormone control, not chemical-powder concentrations. Separately inspected Methods 2.1 excerpts: "NH4Cl was added to 4.5 ppm" (pre-experiment stock culture; unspecified ppm basis) and "250 mL Erlenmeyer flasks" (vessel capacity, not culture volume). Methods 2.2 states "adjusted to 7" for assay-medium pH. The study cites Stein 1973 for BBM; no exact equivalence to the UTEX parent or universal NH4Cl assay dose is asserted. Locator: Methods 2.1-2.3; reference 45.

Provenance

Timestamp	Curator	Action	Notes
2026-01-28	utex-import	Imported from UTEX Culture Collection	Source ID: bold-basal-medium, URL: https://utex.org/products/bold-basal-medium
2026-03-13T06:18:52.974585Z	culturemech-id-assigner-v1.0	Assigned CultureMech ID	Assigned stable identifier: CultureMech:000034
2026-03-17T19:45:03.934229+00:00	normalize_media_names_to_snake_case.py	NAME_NORMALIZED	Normalized name from "Bold Basal Medium" to "bold_basal_medium" for consistent matching
2026-05-09T19:07:13Z	culturemech-agentic-curation	ADDED_GROWTH_EVIDENCE	Added Scenedesmus quadricauda CPCC-158 BBM growth evidence and modeled pH/aeration/estradiol assay conditions as a BBM variant.
2026-05-16T09:02:55.861551+00:00	migrate_legacy_fields.py	MIGRATED_LEGACY_FIELDS	category->lowercase=1
2026-05-16T09:11:01.072242+00:00	migrate_preparation_steps.py	MIGRATED_PREPARATION_STEPS	instruction->action+description for 9 step(s)
2026-08-06T00:58:02.497461+00:00	curate_organism_culture_type.py	SET_ORGANISM_CULTURE_TYPE	Inferred isolate: 1 specific strain(s) named, no community signal (#142)
2026-08-30T00:58:30.632073+00:00	repair_utex_ingredients.py	REPAIRED_UTEX_COMPOSITION	Restored 10 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_bristol_bold_score35.py	RESOLVED_UTEX_BRISTOL_BOLD_SCORE35	UTEX prepares Bold Basal Medium from the six Bristol mineral stocks plus one drop each of BBM EDTA, Iron, Boron, and Bold Trace stocks.
2026-10-10T03:53:28.828041+00:00	codex	CURATED_UTEX_BRISTOL_BBM_INGREDIENT_AND_PREPARATION_EVIDENCE	The BBM trace source prints MnCl with tetrahydrate; its intended chemical identity and the existing MnCl2 amount remain unverified. Added node evidence supports only that source-spelling conflict. BBM trace concentration columns and stock-page parenthetical micromolar values conflict with explicit stock preparation amounts. Preserve inspected Amount-per-litre stock recipes, not those incompatible columns; no new final-medium conversions. The BBM iron stock does not specify acid strength. No density, purity or molarity is assumed. The BBM study cites Stein 1973; exact equivalence with the current UTEX parent is unverified. NH4Cl ppm basis and culture working volume remain unspecified; no numerical conversion or aliquot inference. Bristol-NaCl uses an unfinished parent preparation; its table one-litre row is not certified as a working dose of completed Bristol. The reference and explicit stage notes are retained without a fabricated dose. Optional agar formulations are not silently added to these liquid records. No new taxa-media associations, IDs or growth/role assertions are curated. Supplier-catalog identities, generic incubation/light claims and unrelated preexisting organism evidence are not blanket-certified by this ingredient review.