Enhancing amino acid productivity and profile in black soldier fly larvae through NAT transporter suppression in the excretion system

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 proteins to ensure their viability, facilitating the industrial production. To fulfil the needs of different animals, it is necessary to adjust the profile of essential amino acids (AAs) 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 56.2% decrease in body weight but a 77.3% increase in the total AA content. Notably, the contents of some valuable essential AAs were strongly increased (histidine, 156.8%; valine, 98.1%). These results suggest that inhibiting the function of HiNATt could modify the composition of accumulated AAs. This finding opens a new avenue for producing of BSFL with increased nutritional value as an alternative protein source.