Exploring single cell microbial protein as a sustainable fishmeal alternative in yellowtail kingfish (Seriola lalandi) diets: impacts on health and gut microbiome

Authors

Luke Pilmer, Department of Primary Industries and Regional Development, Fleet Street, Fremantle, Western AustraliaFollow
Lindsey Woolley, Department of Primary Industries and Regional Development, Fleet Street, Fremantle, Perth, Western AustraliaFollow
Alan Lymbery, Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, Western Australia
Chinh Dam, Bioinovation Centre, University of the Sunshine Coast, Maroochydore, Queensland, Australia
Abigail Elizur, Bioinovation Centre, University of the Sunshine Coast, Maroochydore, Queensland, Australia
Md Javed Foysal, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales, Australia
Gavin Partridge, Department of Primary Industries and Regional Development, Fleet Street, Fremantle, Western Australia

Document Type

Article

Publication Date

2-2-2025

Journal Title

Journal of Animal Science and Biotechnology

ISSN

eISSN 2049-1891

Keywords

Alternative proteins, Gene expression, Methanotrophic bacteria, Microbiome, Yellowtail kingfish

Disciplines

Aquaculture and Fisheries | Climate | Environmental Health | Food Biotechnology | Natural Resource Economics | Natural Resources Management and Policy | Oceanography

Abstract

Background

With the global expansion of aquaculture and the increasing demand for fish meal, identifying appropriate and sustainable alternative protein sources for aquafeeds has become essential. Single-cell protein (SCP), derived from methanotrophic bacteria, presents a promising alternative by converting methane into protein, potentially addressing both the need for alternative protein sources and reducing industrial greenhouse gas emissions. This study aimed to evaluate the effects of different levels of SCP inclusion (0%, 25%, 50%, and 75% fish meal replacement) on the health, gene expression, and gut microbiome of yellowtail kingfish (YTK, Seriola lalandi) following a 35-day growth trial.

Results

The study found that SCP inclusion at the highest level of fishmeal replacement (75%) induced a mild inflammatory response in the hindgut of the fish. However, micromorphological assessments of the hindgut, serum biochemistry, and gene expression analyses revealed no significant detrimental effects from SCP replacement. Notably, there were indications of improved lipid digestibility with SCP. Furthermore, SCP inclusion significantly enhanced microbial richness and altered the composition of the gut microbiome, introducing beneficial bacterial taxa that may contribute to improved gut health and resilience.

Conclusions

This study highlights SCP as a viable and sustainable alternative to fish meal in YTK diets. The findings suggest that SCP can be included in YTK diets without adverse health effects at moderate levels and may even offer benefits in terms of lipid digestibility and gut microbiome diversity. These results contribute to the advancement of more sustainable aquaculture practices.

Recommended Citation

Pilmer, L., Woolley, L., Lymbery, A. et al. Exploring single cell microbial protein as a sustainable fishmeal alternative in yellowtail kingfish (Seriola lalandi) diets: impacts on health and gut microbiome. J Animal Sci Biotechnol 16, 16 (2025). https://doi.org/10.1186/s40104-024-01146-w