Bushnell-Haas Agar | Hydrocarbon Degrading Bacteria Medium | Ausamics

Bushnell-Haas Agar

Mineral Salts Medium for Hydrocarbon-Degrading Microorganisms
Cat. No.: AS-1161
HS Code: 3821.00 – Prepared Culture Media for Microorganisms

Overview

Bushnell-Haas Agar is a mineral salts culture medium designed for the isolation, enumeration, and study of hydrocarbon-degrading microorganisms. The formulation was originally developed by Bushnell and Haas (1941) and is widely used in environmental microbiology, petroleum microbiology, and bioremediation research.

The medium provides essential inorganic nutrients including nitrogen, phosphorus, sulfur, magnesium, calcium, and iron, but does not contain a carbon source. This design ensures that microbial growth occurs only when hydrocarbon compounds such as kerosene, diesel, gasoline, paraffin wax, or mineral oil are supplied as the sole carbon and energy source.

Bushnell-Haas Agar is particularly valuable for studying the biodegradation of petroleum hydrocarbons in environmental samples such as soil, water, oil spill residues, and fuel systems. The medium supports growth of hydrocarbon-utilizing bacteria including Pseudomonas spp., Alcanivorax spp., and other environmental degraders.

The neutral pH 7.0 environment closely mimics natural ecological conditions and enables reliable detection of microorganisms capable of metabolizing hydrocarbons.

Applications

Bushnell-Haas Agar is widely used for:

• Isolation and enumeration of hydrocarbon-degrading bacteria from soil, water, fuel, and environmental samples
• Bioremediation studies involving degradation of petroleum contaminants including Total Petroleum Hydrocarbons (TPH) and Polycyclic Aromatic Hydrocarbons (PAH)
• Monitoring microbial contamination in aviation fuels, diesel, lubricants, and petroleum products
• Environmental microbiology research related to oil spills and hydrocarbon biodegradation kinetics
• Enrichment and screening of microorganisms capable of using hydrocarbons as the sole carbon source

Key Features

• Carbon-free mineral salts formulation ensuring selective growth only when hydrocarbons are present
• Supports growth of hydrocarbon-degrading microorganisms, including Pseudomonas aeruginosa and related species
• Suitable for overlay techniques with liquid hydrocarbons or inverted plate methods for volatile hydrocarbons
• Widely used in ASTM, EPA, and environmental monitoring protocols for petroleum microbiology
• Stable pH buffering system that maintains optimal microbial growth conditions
• Characteristic precipitate formation after sterilization (white to yellow-orange) confirms proper preparation and does not affect performance

Composition (per Liter)

Final pH: 7.0 ± 0.2 at 25 °C

Preparation

1. Suspend 23.27 g of dehydrated medium in 1 liter of distilled or purified water.

2. Heat with gentle agitation and bring to boiling until completely dissolved.

3. Dispense into suitable containers or flasks.

4. Sterilize by autoclaving at 121 °C for 15 minutes.

After sterilization, a white precipitate may form and may change to yellow or orange upon cooling. This is normal and does not affect medium performance.

For hydrocarbon utilization studies:

• Add 0.5–1 mL sterile hydrocarbon (e.g., mineral oil, diesel, kerosene) to the agar surface after solidification
• Alternatively, apply volatile hydrocarbons in the lid of inverted plates for vapor-phase exposure

Storage

Dehydrated Medium

Store in a tightly closed container at 10–30 °C, protected from moisture and direct light.

Prepared Plates

Store at 2–8 °C and use within 2 weeks.
Store plates inverted to minimize dehydration.

Discard prepared media if:
• Contamination is observed
• Agar becomes dehydrated
• Significant pH change occurs

Quality & Regulatory Information

Bushnell-Haas Agar is manufactured under controlled conditions for consistent microbiological performance and quality verification.

HS Code: 3821.00 – Prepared culture media for the development or maintenance of microorganisms.

Safety Information

⚠ For laboratory research and industrial use only.
Not intended for human, veterinary, or pharmaceutical use without validation.

• Handle laboratory chemicals using appropriate personal protective equipment (PPE)
• Hydrocarbon supplements may be hazardous and should be handled in a well-ventilated area or fume hood
• Autoclave contaminated materials before disposal