Enhancing the nutritional value of black soldier fly larvae through the nutrient amino acid transporter suppression in the excretion system

Abstract

Abstract Larvae of the black soldier fly (Hermetia illucens, BSFL) are rich in valuable nutrients and offer a promising alternative protein source for animal feeds. Nonetheless, there is a pressing need to improve both the productivity and quality of BSFL to ensure the viability of BSFL products and facilitating the industrial production. To fulfil the needs of different animals, it is necessary to adjust the profile of essential amino acids (EAAs) in BSFL. Insects excrete surplus nutrients to maintain homeostasis; AAs are excreted by nutrient AA transporters (NATs) in the Malpighian tubules. We aimed to modify the composition of essential AAs by silencing the NAT in Malpighian tubules of BSFL (HiNATt). Silencing HiNATt resulted in a 77.3% increase in the total AA content while 56.2% decrease in body weight. Notably, the contents of some valuable essential AAs were strongly increased (histidine, 256.8%; valine, 198.1% in total compared to the intact larva). These results suggest that inhibiting the HiNATt function could modify the amount of accumulated EAAs. This finding opens a new avenue for producing BSFL with increased nutritional value as an alternative protein source.