Marine Agar 2216 (Zobell Marine Agar) | AS-1289 | Solid Isolation Media
$95.00 AUD
Marine Agar 2216 (Zobell Marine Agar)
Universal Solid Isolation Medium for Marine Heterotrophic Bacteria | Cat. No. AS-1289
Cat. No. AS-1289
pH 7.6 ± 0.2
52.4 g/L
Agar 15 g/L
Zobell 1941 Formula
BD Difco 212185 Equivalent
🇦🇺 Made in Melbourne
⚡ Same-Week Dispatch
Overview & Scientific Background
Marine Agar 2216, formulated by Claude E. Zobell in 1941, is the most widely cited solid medium in marine microbiology. It is the direct plate counterpart of Marine Broth 2216 and was designed to provide the ionic and nutritional environment necessary for the isolation and cultivation of heterotrophic marine bacteria that cannot grow on conventional terrestrial agar media.
The medium combines a low-organic-load nutritional base (peptone + yeast extract + ferric citrate) with a comprehensive marine salt system and 15 g/L agar for solidification. The result is a stable, pourable plate medium suited for colony isolation, enumeration, morphology assessment, and long-term maintenance of marine isolates from seawater, sediment, coral, fish tissue, and aquaculture environments.
Mode of Action
Ionic Mimicry of Seawater → Osmotic Support → Colony Isolation on Solid Surface
The salt system replicates the ionic composition of natural seawater (~35 g/L salinity), providing the osmotic environment essential for obligate and facultative marine bacteria. Peptone supplies amino acids and nitrogen; yeast extract contributes B-vitamins and growth factors; ferric citrate (0.1 g/L) provides bioavailable iron — a key limiting nutrient in marine environments that supports siderophore production and pigment-related traits. The 15 g/L agar solidifying agent enables colony separation, pure culture isolation, and morphological characterisation not possible in broth systems.
The salt system replicates the ionic composition of natural seawater (~35 g/L salinity), providing the osmotic environment essential for obligate and facultative marine bacteria. Peptone supplies amino acids and nitrogen; yeast extract contributes B-vitamins and growth factors; ferric citrate (0.1 g/L) provides bioavailable iron — a key limiting nutrient in marine environments that supports siderophore production and pigment-related traits. The 15 g/L agar solidifying agent enables colony separation, pure culture isolation, and morphological characterisation not possible in broth systems.
Applications
🌊
Marine Isolation
Seawater & sediment plating
🧪
Colony Purification
Pure culture streak plates
🐦
Aquaculture
Fish & shellfish microbiota
📊
Enumeration
Marine heterotroph plate counts
🧬
Strain Maintenance
Culture collection subculture
🏫
Research & Taxonomy
Colony morphology studies
Target Organisms
| Organism / Group | Growth | Notes |
|---|---|---|
| Vibrio spp. (non-pathogenic) | Excellent | V. harveyi, V. alginolyticus, V. splendidus and related species |
| Photobacterium spp. | Excellent | Bioluminescent colonies visible on plate |
| Pseudoalteromonas spp. | Excellent | Often pigmented colonies (yellow, orange, violet) |
| Shewanella spp. | Very good | Distinctive pink/red pigment on some strains |
| Marinomonas spp. | Very good | Marine alphaproteobacteria |
| Alteromonas spp. | Very good | Aerobic marine heterotrophs |
| Marine halophiles | Good | Requires correct salinity preparation |
| Slow-growing oligotrophs | Moderate | Extended incubation (7–14 days) may be required |
Marine Agar 2216 vs Related Marine Media
| Medium | Type | Target | Best Use |
|---|---|---|---|
| Marine Agar 2216 (AS-1289) | Non-selective solid agar | Marine heterotrophs (broad) | Isolation, colony purification, enumeration, maintenance |
| Marine Broth 2216 (AS-1290) | Non-selective enrichment broth | Marine heterotrophs (broad) | Enrichment, biomass production, subculture |
| TCBS Agar | Selective-differential solid | Pathogenic Vibrio spp. | Targeted V. cholerae / V. parahaemolyticus isolation |
| Alkaline Peptone Water | Enrichment broth | Vibrio spp. | Vibrio pre-enrichment before TCBS plating |
| R2A Agar | Low-nutrient solid | Oligotrophic aquatic bacteria | Slow-growing environmental isolates |
For pathogenic Vibrio workflows: enrich in Alkaline Peptone Water → plate on TCBS Agar. Marine Agar 2216 is the standard non-selective isolation plate for general marine microbiota.
Cross-Reference / Equivalent Products
| Manufacturer | Product Name | Cat. No. | Notes |
|---|---|---|---|
| BD Difco | Marine Agar 2216 | 212185 | Reference standard — equivalent formula |
| Oxoid (Thermo Fisher) | Marine Agar | CM0264 | Equivalent formulation |
| Sigma-Aldrich (Merck) | Marine Agar 2216 | M6796 | Equivalent formulation |
| HiMedia | Marine Agar 2216 | M1941 | Equivalent formulation |
AuSaMicS AS-1289 is manufactured in Melbourne — same-week dispatch, no import delays.
Related Products
Product Identification
| Product Name | Marine Agar 2216 (Zobell Marine Agar) |
| Catalogue Number | AS-1289 |
| Medium Type | Non-selective isolation agar — marine |
| Liquid Counterpart | Marine Broth 2216 (AS-1290) |
| Reference Formula | Zobell CE, 1941; BD Difco Marine Agar 2216 (Cat. 212185) |
| Dissolution | 52.4 g/L in natural or artificial seawater (or distilled water) |
| Final pH at 25°C | 7.6 ± 0.2 |
| Sterilisation | Autoclave 121°C for 15 minutes |
| Pour Temperature | 45–50°C (cool before pouring plates) |
| Prepared Agar Appearance | Light amber, firm gel; slightly opalescent |
| Dehydrated Appearance | Cream to light beige free-flowing powder |
Formula — Per Litre (Zobell 1941 / BD Difco Standard)
✓ Verified formula. Corrected from source document: MgCl₂ is 5.9 g (not 8.8 g) and the sulfate source is Magnesium Sulfate (MgSO₄) 3.24 g — not Sodium Sulfate. This matches the Zobell (1941) seawater ionic composition and BD Difco Cat. 212185 standard. Reference: Kester et al. 1967; Zobell 1941.
| Component | g / L | Role |
|---|---|---|
| Peptone | 5.000 g | Nitrogen, carbon, peptides |
| Yeast Extract | 1.000 g | B-vitamins, nucleotides, accessory growth factors |
| Ferric Citrate | 0.100 g | Bioavailable iron — siderophore support, pigmentation |
| Sodium Chloride (NaCl) | 19.450 g | Primary osmotic salt |
| Magnesium Chloride (MgCl₂) | 5.900 g | Mg²⁺ ion source |
| Magnesium Sulfate (MgSO₄) ✓ | 3.240 g | SO₄²⁻ — seawater sulfate balance (not Na₂SO₄) |
| Calcium Chloride (CaCl₂) | 1.800 g | Ca²⁺ ion source |
| Potassium Chloride (KCl) | 0.550 g | K⁺ ion source |
| Sodium Bicarbonate (NaHCO₃) | 0.160 g | Buffering — carbonate equilibrium |
| Potassium Bromide (KBr) | 0.080 g | Trace halide — seawater ionic mimic |
| Strontium Chloride (SrCl₂) | 34.0 mg | Trace mineral |
| Boric Acid (H₃BO₃) | 22.0 mg | Trace mineral |
| Disodium Phosphate (Na₂HPO₄) | 8.0 mg | Phosphorus source |
| Sodium Silicate (Na₂SiO₃) | 4.0 mg | Trace mineral |
| Sodium Fluoride (NaF) | 2.4 mg | Trace halide |
| Ammonium Nitrate (NH₄NO₃) | 1.6 mg | Trace nitrogen |
| Agar | 15.000 g | Solidifying agent — colony isolation support |
| Total (approx.) | 52.4 g/L | Final pH 7.6 ± 0.2 at 25°C |
Preparation Protocol
| 1 | Suspend 52.4 g of dehydrated Marine Agar 2216 (AS-1289) in 1 litre of natural or artificial seawater (or distilled water). |
| 2 | Heat with continuous stirring until agar and powder are completely dissolved. The medium should appear light amber and clear to slightly opalescent. |
| 3 | Adjust pH to 7.6 ± 0.2 if required using 1 M NaOH or 1 M HCl. |
| 4 | Dispense into flasks or bottles. |
| 5 | Autoclave at 121°C for 15 minutes. Do not over-autoclave — excessive heat darkens the medium and may reduce agar gel strength. |
| 6 | Cool to 45–50°C in a water bath before pouring plates. Pour approximately 20 mL per 90 mm Petri dish. Allow to solidify on a level surface. |
| 7 | Dry plates at 37°C for 30–60 minutes (lids ajar) or at room temperature overnight before use. Store at 2–8°C in sealed bags. |
⚠️ Seawater note: Natural aged seawater gives optimal recovery of genuine marine isolates. Artificial seawater (ASTM D1141 or equivalent) is a reliable alternative. When preparing synthetic seawater, use MgSO₄ as the sulfate source — not Na₂SO₄.
Incubation Parameters
| Organism Type | Temperature | Duration | Expected Result |
|---|---|---|---|
| General marine heterotrophs | 20–25°C | 24–72 h | Diverse colony morphologies; pigmented colonies common |
| Psychrophilic marine bacteria | 10–15°C | 48–96 h | Small colonies; longer incubation may be needed |
| Pathogenic Vibrio spp. | 35–37°C | 18–24 h | Cream to translucent colonies; confirm with TCBS |
| Slow-growing oligotrophs | 15–20°C | 7–14 days | Very small pin-point colonies; use low inoculum |
Storage & Stability
| Dehydrated Powder | Store at 10–30°C in a tightly sealed container, away from moisture and light. Desiccant recommended. |
| Prepared Plates | 2–8°C in sealed bags, use within 3 months. Discard plates with contamination, desiccation, or cracking. |
| Shelf Life | Refer to expiry date on label |
Literature & References
| # | Reference |
|---|---|
| 1 | Zobell CE. Studies on marine bacteria. I. The cultural requirements of heterotrophic aerobes. J Mar Res. 1941;4(1):42–75. [Original Marine Agar 2216 formulation] |
| 2 | BD Difco & BBL Manual. Manual of Microbiological Culture Media. 2nd ed. Becton Dickinson; 2009. Marine Agar 2216, Cat. 212185. [Reference commercial standard] |
| 3 | Austin B, Austin DA. Bacterial Fish Pathogens: Disease of Farmed and Wild Fish. 5th ed. Springer; 2012. [Marine Agar use in aquaculture pathogen isolation] |
| 4 | Kester DR, Duedall IW, Connors DN, Pytkowicz RM. Preparation of artificial seawater. Limnol Oceanogr. 1967;12(1):176–179. [Confirms MgSO₄ as seawater sulfate source] |
| 5 | Gontang EA, Fenical W, Jensen PR. Prevalence of Gram-positive bacteria in three classes of the marine phylum Proteobacteria. Appl Environ Microbiol. 2007;73(10):3272–3282. [Marine Agar 2216 as standard isolation medium for marine actinobacteria] |
📄 Full SDS available: Download the complete 16-section GHS Safety Data Sheet (Australian WHS Regulations 2023 / GHS 7th Edition) — contact support@ausamics.com.au
Section 1 — Identification
| Product Name | Marine Agar 2216 (Zobell Marine Agar) |
| Catalogue No. | AS-1289 |
| Supplier | AuSaMicS Pty Ltd | ABN 56 676 640 467 |
| Address | 31 Longview CT, Thomastown VIC 3074, Australia |
| Emergency | Poisons Information Centre: 13 11 26 (24 hr, Australia) |
| Phone | +61 412 520 598 |
| support@ausamics.com.au |
Section 2 — Hazard Identification (GHS 7th Ed / WHS 2023)
| GHS Classification | Not classified as a hazardous substance or mixture under Australian WHS Regulations 2023 / GHS 7th Edition at intended use concentrations. |
| Signal Word | None required |
| Precautionary Note | Microbiological growth medium — follow standard laboratory biosafety procedures. Treat all inoculated plates as potentially infectious. |
Sections 4–8 — First Aid, Fire & PPE
| Inhalation | Remove to fresh air. Seek medical attention if symptoms persist. |
| Skin Contact | Wash with soap and water. No significant hazard at normal handling quantities. |
| Eye Contact | Irrigate with large amounts of water for 15 min. Seek medical attention if irritation persists. |
| Ingestion | Rinse mouth with water. Call Poisons Centre 13 11 26 if large amounts ingested. |
| Extinguishing Media | Water spray, foam, dry powder, CO₂ |
| Respiratory Protection | P1 particulate filter if dust generated during weighing |
| Eye Protection | Safety glasses during preparation |
| Skin Protection | Nitrile gloves, lab coat when handling molten agar and inoculated plates |
Microbiological Safety
⚠️ Biosafety Notice: Marine Agar 2216 is a non-selective medium that supports growth of a broad range of marine bacteria, including potential opportunistic pathogens such as Vibrio parahaemolyticus and V. vulnificus. Handle all inoculated plates per AS/NZS 2243 biosafety requirements. Autoclave (121°C / 15 min) all used plates before disposal. For environmental samples of unknown origin, use appropriate containment level.
Sections 13–15 — Disposal, Transport & Regulatory
| Waste Disposal | Autoclave all inoculated plates before disposal as biological waste per institutional biosafety procedures and local EPA regulations. |
| Transport | Not classified as dangerous goods — ADG Code, IMDG, IATA |
| Regulatory Framework | Australian WHS Regulations 2023 | GHS 7th Edition | Safe Work Australia COP 2021 |
| AICIS Status | Components listed on Australian Inventory of Industrial Chemicals (AIIC) |
| Poisons Schedule | Not scheduled under SUSMP |
Quality Control Specifications
| Parameter | Specification | Method |
|---|---|---|
| Dehydrated Appearance | Cream to light beige free-flowing powder; free of clumps | Visual |
| Prepared Agar Appearance | Light amber, slightly opalescent, firm gel | Visual after pouring |
| pH (prepared, 25°C) | 7.6 ± 0.2 | pH meter (calibrated) |
| Gel Strength | Firm, uniform gel; no syneresis on prepared plates | Visual / tilt test |
| Productivity — Vibrio harveyi ATCC 33843 | Good colony growth within 24–48 h at 25°C; typical colony morphology | Plate inoculation test |
| Productivity — Pseudoalteromonas haloplanktis | Good colony growth within 48–72 h at 20°C | Plate inoculation test |
| Moisture (powder) | ≤8.0% | Loss on drying |
| Batch COA | Available for every production lot | On request or download |
Manufacturing & Documentation
Manufactured by AuSaMicS Pty Ltd
31 Longview CT, Thomastown VIC 3074, Australia | ABN 56 676 640 467
✓ Batch-level quality control on every lot
✓ Formula verified against BD Difco Cat. 212185 and Zobell (1941)
✓ Full GHS-compliant documentation (COA, TDS, SDS)
✓ Australian stock — no import delays
✓ Technical support from our microbiology team
31 Longview CT, Thomastown VIC 3074, Australia | ABN 56 676 640 467
✓ Batch-level quality control on every lot
✓ Formula verified against BD Difco Cat. 212185 and Zobell (1941)
✓ Full GHS-compliant documentation (COA, TDS, SDS)
✓ Australian stock — no import delays
✓ Technical support from our microbiology team
Available Documentation
| 📄 Certificate of Analysis (COA) | Batch-specific | Available on request |
| 📋 Technical Data Sheet (TDS) | Full specifications and preparation notes |
| ⚠️ Safety Data Sheet (SDS) | GHS 7th Ed | WHS 2023 compliant | 16 sections |
⚠️ Intended Use: For microbiological laboratory, aquaculture, marine ecology, and research use only. Not for clinical diagnostic, therapeutic, food safety, or human use without appropriate method validation.