Production of single cell protein from waste streams in a biorefinery

Purpose and goal

The project aims to improve the profitability of large-scale forage-based biorefineries by producing single-cell protein (SCP) from byproducts remaining after protein extraction for monogastric animals. In such a biorefinery, green protein for monogastric animals is produced from the liquid fraction after pressing. However, there is potential to develop high-value products from the press cake and other residues to enhance utilization and bring the forage biorefinery closer to commercialization. 

Challenges and Opportunities

One challenge highlighted is the difficulty in achieving profitability in these types of facilities, especially when they operate only during the summer months when fresh forage is available. Therefore, the idea is to utilize the facility for SCP production during the winter months. A goal of producing forage protein is to replace soy protein. However, the conclusion is that to achieve profitability when the protein concentrate replaces GMO-free conventional soy, year-round operation and lower price/raw material costs for the forage are necessary. There is strong interest in using byproducts as cultivation substrates for SCP, as they are expected to contribute to a circular economy and reduce costs. SCP has significant potential as a feed ingredient; experimental evidence shows that the protein it produces can replace soy in feed for fish and monogastric animals. The market potential is substantial, given the drive to replace both soy protein and fishmeal in animal feed with more sustainable alternatives.

Implementation

Within the project, we aim to produce SCP from the brown juice, a byproduct from forage protein production, in laboratory experiments. Additionally, the press cake from protein extraction will be ensiled and pressed again to use the press juice for SCP cultivation.

Goals

The project’s goal is to evaluate SCP production from brown juice derived from fresh forage and press liquor from ensiled fiber fractions in terms of yield and quality.