Healthy ornamental fish through environment-friendly feed based on purple bacteria

For years the ornamental fish industry has been searching for ecological and cost-effective feed ingredients to boost health, fitness and color. UAntwerp has finally made this possible!

Our purple bacteria-based formulation, special sunlight utilizing microbes full of nutritious compounds, stimulates the growth, color, and reproductivity of guppies and protects them against diseases.

Situation before

Ornamental fish is the third and fifth most common group of pets in the United States and the European Union, respectively, with guppy being one of the most popular freshwater tropical fish. Nutrition plays a vital role in assuring the welfare of aquatic animals. The feed market and associated environmental aspects continue to grow, spurring fish feed suppliers to use novel and ecological ingredients to boost health, fitness and color. Microalgal biomass, astaxanthin and several probiotics such as Pediococcus acidilactici are already available in commercial feed formulations for aquarists. These aquafeeds are increasingly preferred by breeders and pet owners, yet their implementation is hampered by the higher associated production costs. An ecological, yet cost-effective alternative is, therefore, highly desirable by the ornamental fish industry to boost health, fitness and color.


Our sustainable feed formulation based on purple bacteria biomass was tested in two feeding trials with guppy fish. The invention entails four key findings:

·       the use of purple bacteria in feed significantly increases the reproduction of aquatic animals. Moreover, it can be used in concentrations that are economically relevant for ornamental fish and aquaculture feed.

·       a significant effect of these purple bacteria on the growth of fish was observed

·       purple bacteria in feed boosts the pigmentation and color of fish

·       surprisingly, purple bacteria aquafeed protects fish against diseases

Partners we search for

We target ornamental fish feed and pet food-producing companies. These companies are experts in feed formulation and have an established local and international distribution network of pet food stores. Such a potential partnership will help to accelerate the introduction of purple bacteria-based ornamental feed in the market.

About the researchers

Two research teams of the University of Antwerp were involved in the development of the purple bacteria fish feed. The team of prof. Siegfried Vlaeminck and Dr. Abbas Alloul (a.k.a. dr. Purple) from the department of Bioscience Engineering are already exploring purple bacteria for almost a decade. Their core expertise relates to the production of these photosynthetic microbes for several industrial applications including protein replacement in animal feed, probiotics and microbial fertilizer.

The team of Prof. Gudrun De Boeck from the department of Biology are leading experts in marine and freshwater fish. Her expertise involves fitness, energy metabolism and iono- and osmoregulation of fish. Due to her expertise, she is appointed as Guest Professor at the Faculty of Bioscience Engineering, University of Ghent, Belgium and at the Institute of Tropical Aquaculture and Fisheries Research, University Malaysia Terengganu, Malaysia.

More information

University of Antwerp 

 Middelheimlaan 1 

 2020 Antwerpen 

 Phone: 03/265.35.99 (Sara Melis)