Transgenic black soldier flies for production of carotenoids.

The black soldier fly (BSF), Hermetia illucens, has gained traction recently as a means to achieve closed-loop production cycles. BSF can subsist off mammalian waste products and their consumption of such waste in turn generates compost that can be used in agricultural operations. Their environmental impact is minimal and BSF larvae are edible, with a nutritional profile high in protein and other essential vitamins. Therefore, it is conceivable to use BSF as a mechanism for both reducing organic waste and maintaining a low-impact food source for animal livestock or humans. The main drawback to BSF as a potential human food source is they are deficient in fat-soluble vitamins such as Vitamins A, D, and E. While loading BSF with essential vitamins may be achieved via diet-based interventions, this undercuts the goal of a closed-loop as specialized diets would require additional supply chains. An alternative is to genetically engineer BSF that can synthesize these essential vitamins. Here we describe a BSF line that has been engineered with the two main carotenoid biosynthetic genes, CarRA and CarB for production of provitamin carotenoids within the Vitamin A family. Our data describe the manipulation of the BSF genome to insert transgenes for expression of functional protein products.