Aquaculture for all

A single celled replacement for fishmeal?

Nutrition Environment +1 more

Large scale production of a single cell organism could reduce the need to use wild-caught fish and agricultural crops as the key protein ingredients in aquaculture feeds, according to a new study published in PEERJ today.

The study, entitled A Transdisciplinary Approach To The Initial Validation Of A Single Cell Protein As An Alternative Protein Source For Use In Aquafeeds, is the result of a collaboration between researchers at a Massachusetts-based biotechnology company – KnipBio, Inc – the New England Aquarium, the University of Massachusetts, Roger Williams University, and the USDA Agriculture Research Service.

The study was designed to test whether diets consisting of between 30% and 100% pelleted bacterium Methylobacterium extorquens could serve as a suitable diet for fish and shrimp. M. extorquens is a common leaf symbiont bacterium that is grown by converting methanol in standard fermentation tanks to produce a product called KnipBio Meal, which has a similar composition of protein, amino acids and other biomolecules to wild fish.

According to Larry Feinberg, CEO of KnipBio: “We conducted this study to answer an important question: ‘Is it possible to recreate the wild fish diet without using non-sustainable wild ingredients?’ The results of the study indicate that a diet made up of single cell protein can serve as a high-quality alternative in aquaculture feeds. Our work since the study was completed indicates that genetic optimization of the single cell protein can further improve these results.”

The study looked at the efficacy of KnipBio Meal as a food for three important aquaculture species: white shrimp, Atlantic salmon and smallmouth grunts. All three species experienced similar or better growth and survival rates when fed a diet containing KnipBio Meal when compared to fish given a diet of conventional commercial feed. In blind taste tests, panelists rated the shrimp raised on the KnipBio Meal mixtures as statistically similar to control shrimp.

Half of the fish that humans eat are farmed, and many require a high-protein diet. Traditionally, aquaculture feeds contain approximately 30% fishmeal. More recently, in an effort to ease pressure on declining ocean fish stocks, farmers have turned to protein-rich plant crops such as soybeans as replacements for fishmeal. The challenge is a soy-rich diet can lead to gut inflammation in many farmed species, resulting in lower growth and survival rates. In the study KnipBio Meal displayed none of these effects.

“In addition to creating healthier fish, there are other inherent benefits to using KnipBio Meal as a replacement for agricultural protein in fish feed. An estimated 100-acre KnipBio facility can match the protein production of a 10,000-acre soy operation, dramatically reducing the environmental footprint for production. The process also eliminates the need for fertilizers and pesticides and reduces energy use,” Feinberg added.

Create an account now to keep reading

It'll only take a second and we'll take you right back to what you were reading. The best part? It's free.

Already have an account? Sign in here