What is PSB (Photosynthetic Bacteria)?

Photosynthetic bacteria (PSB) are microorganisms that use pigments like bacteriochlorophyll to capture light and convert it into chemical energy. They play a key role in nitrogen fixation, water purification, and ecological restoration.

Why do medaka breeders in Japan love PSB?

Because it’s a natural, effective, and safe way to improve water quality. PSB reduces ammonia and stabilizes aquatic environments, minimizing water changes.

How do you use PSB in a medaka tub?

Shake well and add a small amount to the medaka tub weekly. Exposure to sunlight is okay, and regular use supports water clarity and fish health.

Can PSB replace nitrifying bacteria?

Not entirely. PSB assist in reducing ammonia, but nitrifying bacteria remain essential. PSB are best used as complementary support during tank cycling or when ammonia levels spike.

Is there scientific research supporting PSB use?

Yes. Studies, such as those published in ScienceDirect, highlight how PSBs use light energy to perform CO2 fixation and reduce toxic substances like hydrogen sulfide.

Photosynthetic Bacteria (PSB) for Medaka | SNR Medaka USA

Photosynthetic Bacteria (PSB) for Medaka

Photosynthetic Bacteria (PSB) are a fascinating type of microorganisms. They convert light into chemical energy using pigments such as bacteriochlorophyll. Unlike plant-based photosynthesis, PSBs do not release oxygen and do not need water as an electron donor.

These microorganisms live in places like soil, lakes, and aquariums. They are among the oldest life forms on Earth. According to recent research, PSBs can use compounds like sulfur and hydrogen to process carbon dioxide. Their ability to survive in tough conditions makes them useful in many environments.

Types of PSB

Chlorobiaceae: Green sulfur bacteria that use sulfides as electron donors.
Chromatiaceae: Purple sulfur bacteria that thrive in anaerobic, sulfur-rich conditions.
Rhodospirillaceae: Purple non-sulfur bacteria, rod-shaped, adaptive to various environments.
Chloroflexaceae: Green non-sulfur bacteria with flexible metabolism.

Benefits of PSB for Medaka and Aquariums

Reduces ammonia and nitrite levels, improving water quality
Acts as live food for fry and juvenile fish
Boosts fish immunity and reduces disease risks
Helps aquatic plants grow via metabolic byproducts
Speeds up tank cycling by activating other beneficial bacteria
Enhances coloration in medaka due to carotenoids

Usage in Medaka Tubs

Simply add a few drops weekly to your medaka tub or tank. For fry, use a pipette or spray bottle. Avoid overdosing to prevent oxygen depletion. Store in a cool, shaded place. PSB can be used year-round, indoors or outdoors.

How to Culture PSB at Home

Method 1: Using Beer Yeast Tablets (e.g., Ebios)

Add 10–50% PSB stock to a PET bottle.
Fill the rest with tap water (chlorine is okay).
Add 2–4 tablets per 500ml.
Seal tightly and leave in sunlight for 1–2 weeks. Shake daily.

Note: Some strains may not grow well with beer yeast. Use dedicated culture media for reliable results.

Method 2: Using Dedicated Culture Media (Recommended)

Add PSB nutrient extract and PSB seed to a PET bottle or water tank.
Fill to the top with tap water to create an anaerobic environment.
Expose to sunlight or plant light for 1–2 weeks.
Color may vary from red to orange—still effective.

Applications Beyond Aquariums

Odor control in animal farms
Wastewater treatment across industries
Soil improvement and crop yield boost
Carbon capture and greenhouse gas reduction

PSB also produce valuable substances such as Coenzyme Q10, carotenoids, polyphosphates, and PHB, which are used in health supplements, cosmetics, and agriculture.