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Microbes convert food waste to environmentally friendly fish feed

In this project, we evaluate the possibility to use microbes growing on food waste as an environmentally friendly alternative to today's fish meal and soy in fish feed.

The waste is initially converted by anaerobic microbial process that involves so-called acetogenic bacteria to the main product; acetic acid. Acetic acid and residual nutrients are then used as substrates for oxygenated yeast culture, and the yeast is then used as a feed ingredient.

The new feed is evaluated both from a systems perspective with a life cycle assessment (LCA) and from a biological perspective in trials with fish.

Read more about the four sub projects below.

Project 1

We study anaerobic hydrolysis of different kinds of food wastes to determine how the yields of acetic acid can be maximized. How much of the carbon in the waste gets turned into acetic acid?

Project 2

We study how well different kinds of yeast can be cultivated on acetic acid with the highest possible yields of carbon, nitrogen, phosphorous and other nutrients.

Project 3

We study the feed properties of the produced yeast biomass, for example the protein and vitamin content. The feed will also be tested in an aquaculture system to study its physiological effects on farmed fish.

Project 4

We perform a life cycle analysis (LCA) where the environmental impact of the new feed as used in aquaculture will compared to a conventional feed of equivalent nutritional value (e.g. soy).

Published: 23 May 2023 - Page editor: adrian.dauphinee@slu.se


Professor Anna Schnürer, Project coordinator

E-mail: anna.schnurer@slu.se

Telephone: +46 18 67 32 88