April 17, 2017
US firm finds replacement for fish protein in salmon feed
A US-based biotechnology company reports that a single-celled protein contained in bacteria has been found to be an effective replacement for wild-caught fish and agricultural crops as an ingredient in the manufacture of salmon feed.
KnipBio said it did a study in collaboration with the New England Aquarium, the University of Massachusetts at Boston, Roger Williams University and the USDA Agriculture Research Service to test whether a diet consisting of between 30% and 100% of the bacterium Methylobacterium extorquens in pellet form would sustain fish and shrimp.
M. extorquens is cultured by conversion of methanol through fermentation in tanks. Instead of beer, the fermentation produced a bacterium, which the company calls KnipBio Meal. It has a composition of protein and amino acids very similar to the protein found in wild fish, it said.
"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 studies were conducted shows that the genetic optimisation of single-cell proteins also further improve these results," said Larry Feinberg, KnipBio chief executive.
KnipBio said the study, entitled "A Transdisciplinary Approach to the Initial Validation of a Single Cell Protein as an Alternative Protein Source for Use in Aquafeeds", found that white shrimp, Atlantic salmon and smallmouth grunts fed a diet containing KnipBio Meal had similar or better growth and survival rates than fish given a diet of conventional commercial feed.
"The results of the study suggest that a diet consisting of single-cell protein can be a high-quality alternative fish feed. Our work since the study was completed indicates that genetic optimisation of the single-cell protein can further improve these results," Feinberg said.
The company, moreover, pointed out the disadvantage of a soy-rich feed in that it "can lead to inflammation in the intestines of various aquaculture species", which it said could be avoided using M. extorquens.