Associative Nitrogen-Fixing Bacteria Medium - BioReagent

Cat. No.: A1528584

GRADE & PURITY BioReagent

Storage

Room temperature

Shipped In

Normal

Vue d’ensemble

For the cultivation of Azospirillum

Specifications

Spécifications et pureté

BioReagent

Conditions de stockage de stockage

Room temperature

Expédié en

Normal

Grade

BioReagent

Product Line

Produits biologiques

Application Protocols

Item-specific facts (from Product Data)

• Manufacturer Applications: Not specified in the Product Data.

General protocols (literature; adapt to your organism; not product specifications)

• Preparation (broth):
  1. Weigh the dehydrated medium per label directions (concentration not specified; refer to CoA/Spec Sheet).
  2. Add to high-purity water with stirring until dissolved. Adjust pH as required.
  3. Autoclave at 121 °C for 15–20 min. Cool; aseptically add heat-labile supplements if needed.
• Semi-solid/agar plates:
  • If using an agar-supplemented variant, autoclave and pour plates at ~50–55 °C. For semi-solid assays, use low agar (literature: ~0.2–0.5%) to visualize pellicles/graduated motility associated with nitrogen fixation under microaerobic conditions.
• Inoculation and incubation:
  • Inoculate aseptically. Incubate at organism-appropriate temperature (many diazotrophs 25–32 °C) and oxygen regime (microaerophilic or static).
• Verification:
  • Confirm nitrogen fixation by acetylene reduction assay or molecular markers (nifH PCR) rather than growth alone.

Controls and QC

• Include negative controls (non-diazotroph) and nitrogen-supplemented controls to benchmark selectivity. Record lot number, pH, sterilization conditions, and incubation parameters for reproducibility.

Biological Roles

General biological context (not product specifications)

• Associative nitrogen-fixing bacteria are diazotrophs that colonize plant rhizospheres and tissues without forming specialized nodules. They reduce atmospheric N2 to NH3 via the nitrogenase enzyme complex (MoFe- and Fe-proteins), supplying assimilable nitrogen under nitrogen-limited conditions.
• These organisms commonly utilize microaerophilic niches and rely on respiratory protection or spatial strategies to protect nitrogenase from O2 inactivation. Trace metals (Fe, Mo, sometimes V) and energy from carbon catabolism are essential.

Medium’s functional role (general)

• A selective pressure is created by limiting combined nitrogen while supplying an accessible carbon source and essential minerals, thereby enriching for true diazotrophs. Some media incorporate pH buffering near neutrality, Mg/Ca for enzymatic functions, and trace elements for metalloenzyme assembly.
• When used with appropriate assays (e.g., acetylene reduction), growth on such media can support the inference of nitrogen-fixation capability, although genetic confirmation (nif gene markers) is recommended.

Applicability and scope

• Suitable target groups in literature include Azospirillum spp. (rhizosphere-associated), Herbaspirillum spp. (endophytes), and related taxa. Specific growth responses and optimal conditions vary by species/strain; consult organism-specific protocols.

Item-specific note

• This section provides biological background only. No claims are made regarding performance for specific strains because the Product Data do not include organism-specific validations. For research use only.

Buffer Applications

Applicability note

• This product is a culture medium rather than a classical buffer. However, buffering capacity and pH control are critical to successful cultivation of diazotrophs.

General guidance (literature; not product specifications)

• Typical target pH at 25 °C for associative nitrogen-fixation media: ~6.5–7.2. Exact value depends on organism and carbon source (e.g., malate-based media may tolerate slightly acidic pH).
• Common buffering systems: phosphate buffers (mixes of KH2PO4/K2HPO4) or Good’s buffers at low concentrations to avoid excess nitrogen input. Bicarbonate/CO2 systems are used when cultivating under controlled atmospheres.
• Practical tips:
  • Adjust pH before sterilization; re-check after autoclaving and fine-tune aseptically if needed.
  • Avoid high concentrations of ammonium or nitrate in the buffer salts, which would defeat nitrogen-limitation selectivity.
  • Use calibrated pH electrodes compatible with low-ionic-strength solutions.

Item-specific note

• No buffer composition or target pH is specified for this item; consult the CoA/Spec Sheet or your lab’s validated protocol. If heat-labile buffers or vitamins are used, filter-sterilize and add post-autoclave.

Green Alternatives

Context

• While culture media are not solvents, sustainability considerations apply to preparation, sterilization, and waste handling.

Greener practice options (general)

• Energy-efficient sterilization: Optimize autoclave loads and cycles (validated 121 °C, 15–20 min) to reduce energy consumption; avoid double-autoclaving sugar-rich media to limit degradation.
• Reusable materials: Use glass media bottles and stainless steel caps where feasible; employ autoclavable cultureware to reduce single-use plastics.
• Right-sizing: Prepare only the volume required to minimize expired waste. Aliquot and store as appropriate to avoid repeated heat cycles.
• Water stewardship: Utilize closed-loop or recirculating chillers for autoclave vacuum/condensers where available; verify local policies.
• Waste management: Autoclave biological waste prior to disposal; segregate nutrient media from solvent/chemical waste streams.

Comparison table (general)

• Dehydrated medium vs ready-to-use liquid:
  • Dehydrated: lower shipping mass/volume, reduced packaging, longer shelf life prior to reconstitution; requires in-house sterilization.
  • Ready-to-use: higher convenience and sterility assurance; increased transport emissions due to water weight and often cold-chain for some formats (not specified here).

Item-specific limitations

• No composition details are provided for this item; consult the CoA/Spec Sheet for any statements regarding sustainable sourcing of components or additives.

Pharmaceutical Uses

Applicability note

• This product is a research-grade culture medium. It is not an excipient and is not intended for pharmaceutical formulation, clinical diagnostics, or therapeutic use.

Potential roles in pharmaceutical R&D (general, non-clinical)

• Microbial cultivation studies in discovery research (e.g., microbiome-related evaluations of diazotroph interactions with plants—outside the clinical domain).
• Method development for environmental monitoring or process microbiology in non-sterile manufacturing environments, if relevant to agricultural biotechnology research.

Compliance and documentation

• BioReagent grade is for research use only. For cGMP, clinical, or compendial applications, media would require additional qualifications (e.g., USP/EP monographs, sterility validations, growth promotion tests) that are not specified for this item.

Item-specific statement

• No pharmacopeial status, excipient role, or clinical application is provided in the Product Data. Use strictly for research per the Research Use Note.

Physical Properties

Item-specific facts (from Product Data)

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Physical form: Not specified for this item; refer to CoA/Spec Sheet (commonly supplied as powdered dehydrated medium or as a ready-to-use liquid; confirm on label/CoA).

Quantitative specifications

• Boiling point, melting point, density, refractive index, pH, osmolality: Not specified for this item; refer to CoA/Spec Sheet.

General/literature context (not product specifications)

• Dehydrated culture media are typically free-flowing powders hygroscopic to varying degrees; they dissolve in purified water with stirring and are sterilized by autoclaving (121 °C) or filtration for heat-labile supplements.
• Working pH for associative nitrogen-fixation media is commonly adjusted near neutral (typical literature range ~6.5–7.2 at 25 °C), but exact setpoint is formulation- and organism-dependent. Do not infer for this product—verify on CoA/protocol.
• Solubility: Formulated to be water-soluble/dispensable; turbidity may persist until sterilization if agar or poorly soluble components are included (general observation).

Notes

• Because this is a multi-component mixture, single-number physicochemical properties (e.g., logP, pKa) are not applicable.

Quality and Grades

Item-specific facts (from Product Data)

• Grade: BioReagent.
• Purity: Not specified for this item; refer to CoA/Spec Sheet.

What BioReagent grade implies (general)

• BioReagent-grade materials are suitable for biological research workflows, emphasizing consistency, low bioburden (prior to intentional inoculation), and controlled levels of impurities that could interfere with microbial growth or biochemical assays. They are not validated for clinical or diagnostic use.

Quality controls typically associated with culture media (general)

• Growth promotion testing: Media are often qualified by demonstrating expected growth/enrichment of representative organisms (e.g., associative diazotroph strains) under specified conditions.
• Physicochemical checks: Appearance, moisture content, pH after preparation, and clarity/turbidity (for broths) or gel strength (for agars) are commonly monitored.
• Trace component control: For nitrogen-fixation studies, background fixed-nitrogen (e.g., ammonium, nitrate) is critical and typically minimized/controlled; verify on CoA if relevant to your application.

Stabilizers and additives

• Stabilizers, indicators, or dyes: Not specified for this item; refer to CoA/Spec Sheet.

Documentation and lot traceability

• For regulated research environments, retain the CoA and lot information. Record preparation parameters (water quality, pH adjustment, sterilization cycle) to ensure run-to-run reproducibility.

Reaction and Applications

Scope (general; microbiology applications)

• Designed for cultivation and enrichment of associative nitrogen-fixing bacteria (diazotrophs) that colonize plant rhizospheres and tissues. Typical genera in literature include Azospirillum, Herbaspirillum, Gluconacetobacter, Azoarcus, and Burkholderia (sensu lato). The medium’s low fixed-nitrogen content favors organisms capable of N2 reduction via nitrogenase.

Common laboratory uses

• Enrichment/selective cultivation from environmental or plant-associated samples.
• Isolation on semi-solid or solidified variants to observe pellicle formation indicative of microaerophilic N2 fixation.
• Pre-culture for downstream physiological assays (acetylene reduction assay, nitrate assimilation controls) and genomic/transcriptomic studies.
• Enumeration using MPN techniques under microaerobic conditions.

Practical tips (general)

• Oxygen regime: Nitrogenase is O2-sensitive; microaerobic conditions (e.g., soft agar stabs, gas-permeable closures, controlled headspace) often improve expression.
• Trace metals: Molybdenum and iron are essential cofactors for MoFe nitrogenase; avoid chelating contaminants and verify supplement strategy if your protocol calls for defined trace solutions.
• Carbon sources: Diazotrophs often prefer organic acids (e.g., malate) or certain sugars; match the carbon source to the target organism per literature protocols.
• Controls: Include a non-diazotrophic control and nitrogen-supplemented control medium to verify selectivity.

Item-specific note

• Manufacturer Applications field: Not provided in Product Data. Use cases above are generalized from literature for associative N-fixers. Confirm suitability for your organism/assay.

Reaction Conditions

Not typically applicable to chemical reactions

• This section refers to conditions for chemical transformations (solvents, catalysts, yields), which are not relevant to a culture medium.

Microbiological preparation conditions (general, literature; not product specifications)

• Reconstitution: Dissolve the specified mass of dehydrated medium in high-purity water (concentration not specified for this item; refer to CoA/Spec Sheet). Mix until fully dispersed.
• pH: Adjust to the target value suitable for the intended organism (typical literature range ~6.5–7.2), using minimal nitrogen-containing bases/acids to preserve selectivity.
• Sterilization: Autoclave at 121 °C for 15–20 minutes (standard lab practice). Cool to ~50–55 °C before adding sterile, heat-labile supplements. For agar media, pour plates aseptically.
• Incubation: Many associative diazotrophs prefer 25–32 °C and microaerophilic conditions; verify for your strain.

Item-specific note

• Exact preparation mass/volume, pH target, and supplements are not provided in the Product Data. Consult the CoA/Spec Sheet or validated organism-specific protocols.

Safety and Handling

Item-specific facts (from Product Data)

• GHS classification, signal word, pictograms, H-statements: Not specified for this item; refer to the SDS for authoritative hazard information.
• Storage conditions: Room temperature (per Product Data). Shipped under normal conditions.

General laboratory safety (guidance; defer to SDS/IBR)

• PPE: Wear lab coat, safety glasses, and appropriate gloves. Handle powders to minimize dust generation; consider a dust mask or work in a fume hood if airborne dust may occur.
• Incompatibilities: Avoid contact with strong oxidizers and strong acids/bases unless specified by preparation protocol. Keep dry until use to prevent clumping and microbial contamination.
• Microbiological risk: The medium itself is not a biological agent, but it will support growth of microorganisms. After inoculation, treat all cultures, spills, and waste as biohazardous; follow BSL-appropriate practices and autoclave waste before disposal.
• First-aid overview: Inhalation of dust—move to fresh air. Eye/skin contact—rinse with water. Ingestion—rinse mouth. Seek medical attention if symptoms persist. Always consult the SDS for detailed instructions.
• Sterilization cautions: During autoclaving, do not tightly cap containers; allow steam venting to prevent overpressure. Avoid overheating of sugar-containing media to limit caramelization and Maillard reactions.

Housekeeping

• Label all containers with content and date. Segregate from food/drink areas. Maintain dry storage to limit caking and maintain performance.

Solvent Selection

Applicability note

• Traditional solvent selection does not apply to a culture medium. However, the quality of water used for reconstitution is critical to performance.

Water quality considerations (general guidance)

• Use high-purity water (e.g., ASTM Type I/II or equivalent; 0.2 µm filtered) to minimize background nitrogen and metal contaminants that can influence diazotrophic growth and enzyme activity.
• Avoid chlorinated tap water; residual disinfectants (chloramine, chlorine) and hardness can inhibit growth and alter medium chemistry.

Sterilization compatibility

• Heat-stable base medium may be autoclaved (literature: 121 °C, 15–20 min) unless otherwise indicated. Heat-labile supplements (e.g., vitamins) should be filter-sterilized (0.22 µm) and added aseptically post-autoclave.

Media format choices

• Liquid broth vs agar plates: Choose broth for enrichment and MPN assays; choose agar (if using an agar-supplemented version) for colony isolation and semi-solid motility assays.

Comparison (general)

• Dehydrated powder (reconstituted with water): maximal flexibility and shelf-life; requires autoclave access.
• Ready-to-use sterile liquid: convenience and consistency; higher shipping/storage footprint. Confirm which format applies to this item on the CoA/Spec Sheet.

Storage and Reconstitution

Item-specific facts (from Product Data)

• Storage conditions: Room temperature.
• Shipped in: Normal.
• Appearance and concentration: Not specified for this item; refer to CoA/Spec Sheet.

General storage guidance (for dehydrated media; not product specifications)

• Keep container tightly closed in a cool, dry place. Protect from moisture and direct sunlight to prevent caking and degradation. Use desiccant if appropriate. Do not store near volatile chemicals that could be absorbed by the medium.
• Shelf life: Follow label/CoA. Record first opening date and reseal promptly.

Reconstitution and sterilization (general; follow your CoA/label)

• Reconstitution: Add the specified mass of medium to the appropriate volume of high-purity water. Concentration is not specified for this item; refer to CoA/Spec Sheet.
• pH adjustment: Adjust to the target pH suitable for your organism (literature: ~6.5–7.2). Verify pH after sterilization.
• Sterilization: Autoclave at 121 °C for 15–20 minutes. For heat-labile supplements (e.g., vitamins, trace elements), sterile-filter (0.22 µm) and add aseptically after cooling to ~50 °C.
• Storage of prepared medium: Store at 2–8 °C protected from light. Use promptly (commonly within 2–4 weeks for plates; 1–2 weeks for broth) unless otherwise validated. Warm to room temperature before use and inspect for contamination/turbidity.

Research use

• For research use only, as stated in the Product Data.

Structure and Identity

Item-specific facts (from Product Data)

• Product: Associative Nitrogen-Fixing Bacteria Medium (SKU: A1528584)
• Grade: BioReagent
• CAS: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
• SMILES / InChIKey: Not applicable for a multi-component culture medium.

General description

• This product is a complex, multi-component microbiological culture medium formulated for the cultivation of associative nitrogen-fixing (diazotrophic) bacteria. Such media typically contain a carbon source, mineral salts, micronutrients, and a very low fixed-nitrogen level to select for N2-fixing organisms. Exact composition and concentrations are formulation-dependent and should be confirmed on the CoA/Spec Sheet.

2D/functional features (general, literature)

• Functional classes commonly present: carbon source (e.g., malate, sucrose), phosphate buffer, Mg/Ca salts, trace metals (Mo/Fe for nitrogenase cofactors), possible vitamins; solid formulations may include agar. No single defined “structure” exists because this is a mixture.

Scope and identity notes

• Intended use: laboratory cultivation/enrichment of plant-associated diazotrophs (e.g., Azospirillum, Herbaspirillum, Gluconacetobacter) under research conditions. For research use only.

Synthetic Utility

Not typically applicable

• As a microbiological culture medium, this product is not used as a reagent or building block in chemical synthesis. Therefore, concepts such as functional-group transformations, named organic reactions, and retrosynthetic roles do not apply.

Practical redirection

• For relevant information, see Reaction & Applications (microbiological use), Buffer Applications (pH control), and Storage & Reconstitution (preparation and sterilization).

Target Specificity

Item-specific facts (from Product Data)

• Antigen/epitope, clone, isotype, or species reactivity: Not applicable; no immunochemical targeting information is associated with this culture medium.

General note

• The medium is intended for cultivation of associative nitrogen-fixing bacteria broadly, without species-specific biochemical targeting claims provided in the Product Data.

Foire aux questions

How should this product be stored?

Store at room temperature.