IJdema F, Lievens S, Smets R, Poma G, Van Der Borght M, Lievens B, De Smet J
CLMT Research Group for Insect Production and Processing, Department of Microbial and Molecular Systems (M(2)S), KU Leuven, Geel Campus, Kleinhoefstraat 4, 2440 Geel, Belgium; CMPG Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), Department of Microbial and Molecular Systems (M(2)S), KU Leuven, Kasteelpark Arenberg 22, 3001 Leuven, Belgium.
CSCE Research Group for Insect Production and Processing, Department of Microbial and Molecular Systems (M(2)S), KU Leuven, Geel Campus, Kleinhoefstraat 4, 2440 Geel, Belgium; Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
Animal. 2025 Jan;19(1):101383. doi: 10.1016/j.animal.2024.101383. Epub 2024 Nov 26.
Black soldier fly larvae (BSFL, Hermetia illucens) contain high amounts of proteins and essential amino acids and are therefore an appropriate feed source. However, they lack essential fatty acids (FAs), specifically ω-3 and ω-6, making them a less desirable feed choice for aquaculture. The aim of this study was to increase the ω-3 and ω-6 FA concentrations in BSFL by manipulating the FA composition in their rearing substrate. Specifically, the potential of substrate fermentation using the ω-3 and ω-6 FA-producing fungus Mortierella alpina was assessed. Fermentation of two agricultural side streams (wheat bran (WB) and WB with distiller's dried grains with solubles (DDGS)) increased substrate total crude fat concentration by 2.1 - 4.6%, as well as the concentration of several essential FAs, including the ω-6 FAs arachidonic acid (from less than 0.2 mg/g fat to a maximum of 44.2 mg/g fat) and gamma-linolenic acid (from less than 1.2 mg/g fat to a maximum of 45.8 mg/g fat and the ω-3 FA eicosapentaenoic acid (EPA) (from less than 0.7 mg/g fat to a maximum of 49.9 mg/g fat). Rearing BSFL on feeds from such fermented substrates resulted in similar changes in larval FA composition, specifically a higher concentration of EPA (from less than 0.2 mg/g fat to a maximum of 26.6 mg/g fat in the larvae fed on fermented diets), however, larval growth was reduced. Feeds made from fermented substrates were prone to stickiness and dehydration, possibly limiting larval movement and feeding, thereby affecting larval growth. Furthermore, proximate analysis of the substrates revealed sugar depletion after fermentation, which could be detrimental for larval growth and illustrate important attention points going forward. This study shows that fermentation of agricultural side streams WB and a mixture of WB with DDGS with Mortierella alpina alters their FA profile, increasing their ω-3 and ω-6 FA concentrations and that of BSFL fed with those substrates. Therefore, these results suggest that BSFL with tailor-made FA profiles for a specific application could be successfully produced.
黑水虻幼虫（BSFL，亮斑扁角水虻）含有大量蛋白质和必需氨基酸，因此是一种合适的饲料来源。然而，它们缺乏必需脂肪酸（FAs），特别是ω-3和ω-6脂肪酸，这使得它们在水产养殖中不是理想的饲料选择。本研究的目的是通过控制黑水虻幼虫饲养基质中的脂肪酸组成，来提高其ω-3和ω-6脂肪酸的浓度。具体而言，评估了使用能产生ω-3和ω-6脂肪酸的高山被孢霉对基质进行发酵的潜力。对两种农业副产物（麦麸（WB）以及添加了玉米酒糟可溶性物（DDGS）的麦麸）进行发酵，使基质的总粗脂肪浓度提高了2.1%-4.6%，同时也提高了几种必需脂肪酸的浓度，包括ω-6脂肪酸花生四烯酸（从低于0.2毫克/克脂肪增至最高44.2毫克/克脂肪）和γ-亚麻酸（从低于1.2毫克/克脂肪增至最高45.8毫克/克脂肪）以及ω-3脂肪酸二十碳五烯酸（EPA）（从低于0.7毫克/克脂肪增至最高49.9毫克/克脂肪）。用这种发酵基质制成的饲料饲养黑水虻幼虫，会使幼虫的脂肪酸组成发生类似变化，特别是EPA浓度更高（以发酵饲料喂养的幼虫中，EPA从低于0.2毫克/克脂肪增至最高26.6毫克/克脂肪），然而，幼虫生长减缓。由发酵基质制成的饲料容易发粘和脱水，这可能会限制幼虫的活动和进食，从而影响幼虫生长。此外，对基质的近似分析表明，发酵后糖含量减少，这可能对幼虫生长不利，并说明了未来需要重点关注的问题。本研究表明，用高山被孢霉对农业副产物麦麸以及麦麸与玉米酒糟可溶性物的混合物进行发酵，会改变它们的脂肪酸谱，提高其ω-3和ω-6脂肪酸浓度以及以这些基质喂养的黑水虻幼虫的脂肪酸浓度。因此，这些结果表明，可以成功生产出具有针对特定应用量身定制的脂肪酸谱的黑水虻幼虫。
