Modulating the fatty acid composition of black soldier fly larvae via substrate fermentation

Area of Science:

• Aquaculture nutrition
• Insect farming
• Biotechnology

Background:

• Black soldier fly larvae (BSFL) are a protein-rich feed source for aquaculture.
• BSFL naturally lack essential fatty acids (ω-3 and ω-6), limiting their use.
• Enhancing BSFL fatty acid profiles is crucial for sustainable aquaculture feeds.

Purpose of the Study:

• To increase ω-3 and ω-6 fatty acid concentrations in BSFL.
• To evaluate the fermentation of agricultural side streams with Mortierella alpina for BSFL feed.
• To assess the impact of altered fatty acid profiles on BSFL growth.

Main Methods:

• Fermentation of wheat bran (WB) and WB with distiller's dried grains with solubles (DDGS) using Mortierella alpina.
• Analysis of fatty acid composition in fermented substrates and BSFL.
• Rearing BSFL on fermented substrate-based diets and evaluating larval growth.

Main Results:

• Fermentation significantly increased total crude fat and essential fatty acids (arachidonic acid, gamma-linolenic acid, eicosapentaenoic acid (EPA)) in substrates.
• BSFL fed fermented diets showed higher EPA concentrations.
• Larval growth was reduced, potentially due to feed stickiness, dehydration, and sugar depletion.

Conclusions:

• Fermentation with Mortierella alpina effectively alters the fatty acid profile of agricultural side streams.
• BSFL fed these substrates incorporated higher levels of ω-3 and ω-6 fatty acids.
• Further research is needed to optimize fermentation processes and substrate composition for improved BSFL growth and tailor-made fatty acid profiles.