Gas to protein: Microbial single cell protein is an alternative to fishmeal in aquaculture

Authors

Lindsey Woolley, Department of Primary Industries and Regional Development, Fremantle, Western AustraliaFollow
Md Reaz Chaklader, Department of Primary Industries and Regional Development, Fremantle, Western AustraliaFollow
Luke Pilmer, Department of Primary Industries and Regional Development, Fremantle, Western AustraliaFollow
Frances Stephens, Independent, Dalgety Road, Middle Swan, Western Australia,
Catherine Wingate, University of Western Australia, Perth, Western Australia
Michael Salini, Ridley Agriproducts Pty Ltd, Robart Court, Narangba, Queensland, Australia
Gavin Partridge, Department of Primary Industries and Regional Development, Fremantle, Western Australia

Document Type

Article

Publication Date

2-10-2023

Journal Title

Science of The Total Environment

ISSN

ISSN 0048-9697 eISSN 1879-1026

Keywords

Methanotrophic bacteria, Methane, Aquafeed, Single-cell protein (SCP), Fishmeal, Barramundi, Asian seabass, Commercial farming

Disciplines

Animal Experimentation and Research | Aquaculture and Fisheries | Food Biotechnology | Management Sciences and Quantitative Methods | Natural Resource Economics | Natural Resources and Conservation | Operations and Supply Chain Management

Abstract

Methanotrophic bacteria represent an appealing opportunity to convert methane, a potent greenhouse gas, into a highly nutritious animal feed ingredient, single-cell protein (SCP). SCP has a comparable or superior nutritional profile that to most conventional protein sources and can be produced within a lower environmental footprint. The present study investigated the effect of replacing fishmeal (FM) with methanotrophic SCP in diets for barramundi (Lates calcarifer), a carnivorous fish with a high demand for dietary protein and energy. Dietary inclusion levels of 0 %, 10 %, 20 % and 30 % SCP (representing 0, 25, 50 and 75 % FM replacement) were tested, with and without additives. Triplicate groups of juvenile barramundi were fed the diets over 31 days. The inclusion of SCP significantly improved weight gain and feed conversion efficiency (FCE). Dietary SCP inclusion supported good gut health, with decreasing trends of hepatosomatic index, improved plasma biochemistry, and no adverse histopathological changes. Barramundi fed the SCP diets showed an intact intestinal barrier and a significant improvement in villi and lamina propria area when fed the additive supplemented SCP diets. This study demonstrates that this SCP is highly palatable to barramundi (even without dietary additives) and can replace up to 75 % FM with significant improvements in growth and FCE.

Recommended Citation

Lindsey Woolley, Md Reaz Chaklader, Luke Pilmer, Frances Stephens, Catherine Wingate, Michael Salini, Gavin Partridge, Gas to protein: Microbial single cell protein is an alternative to fishmeal in aquaculture, Science of The Total Environment, Volume 859, Part 1, 2023, 160141, ISSN 0048-9697, https://doi.org/10.1016/j.scitotenv.2022.160141.