Spirulina powder, the dried biomass of cyanobacteria (blue-green algae) and one of the SCP products with much potential as aquafeed ingredients
Potential sources of single-cell protein products
Thursday, March 26, 2020, 05:30 (GMT + 9)
Seafood from wild-catch and aquaculture is the largest animal protein industry in the world. Wild-catch tonnage has been stable since 1990 at around 90 million tons, so aquaculture essentially accounts for the growth since (Fig. 1). Aquaculture has grown faster than any animal protein sector at approx. 7 percent compound annual growth rate over the past two decades, compared to about 4 percent for poultry. Feed is a major cost in livestock production, and protein ingredients are the main cost of aquafeeds.
Efficient feed – and particularly protein conversion – is essential to manage production costs and improve the sustainability of aquaculture. Generally, aquacultured species have relatively lower feed conversion ratios (FCRs) of 1.1 to 1.6 kg of feed per kg of edible seafood, compared to 1.4 to 1.8 for poultry, 2.6 to 4.4 for pork, and 3.5 to 9 for beef. Consequently, aquaculture contributes to a more sustainable animal protein industry, and single cell protein (SCP) is ready to play a major role in its future of aquaculture.
Fig. 1: Growth of the aquaculture industry and the potential fishmeal shortage. Total animal protein production in million metric tons from 1990 to 2025. Adapted from the original article.
Even with diminishing inclusion of fishmeal in aquaculture feeds (Fig. 2), an estimated shortage ranging from 0.4 to 1.32 million metric tons could occur by 2050. Plant-based ingredients can be refined to improve compatibility with aquaculture diets, for example, by removing anti-nutritionals like phytic acid [the major storage form of phosphorous in nuts, cereals, legumes and oil seeds], but this increases cost and most successes so far have come with species for which we have the most nutritional knowledge, for example, salmonids.
Fig. 2: Fishmeal consumption for aquaculture applications through 2015 and projected consumption through 2050 is presented (blue line). Average fishmeal inclusion (green line) from known data through 2015 and projected growth of aquaculture through 2050 with the assumed flat supply of fishmeal. Inclusion is calculated by dividing the fishmeal consumption (blue line) by total feed, which is calculated by multiplying aquaculture output (Fig. 1) by an average feed conversion ratio (FCR) of 1.2. Two alternative scenarios, in which fishmeal inclusion levels do not achieve targeted reductions, are considered: Scenario 1 (solid red) and Scenario 2 (dashed red). Scenario 1 assumes only 85 percent of the reduction target is met, and Scenario 2 assume only 50 percent of the reduction target is met. Adapted from original article.
Consequently, there is demand for more suitable protein ingredients that maintain feed performance, benefit aquaculture health and stabilize supply and economics during the industry expansion. SCP has the potential to deliver multiple solutions through a myriad of products and production approaches, but considerable research, development and particularly scale-up is still required.
This article – adapted and summarized from the original (Jones et al., 2020. Recent advances in single cell protein use as a feed ingredient in aquaculture. Current Opinion in Biotechnology, Volume 61, February 2020, Pages 189-197) reviews some potential sources of SCP products, and some recent advances in their use as a feed ingredient in aquaculture.
Author: Shawn W. Jones, Ph.D. Alon Karpol, Ph.D. Sivan Friedman Biniam T. Maru, Ph.D. Bryan P. Tracy, Ph.D | Read full article here (Global Aquaculture Alliance)