In Indonesia and many other countries, access to affordable and nutritious animal protein remains a serious challenge, especially for low-income families. But a tiny insect—the black soldier fly (BSF) maggot—may hold the key to transforming food waste into a valuable protein source for fish farming.
A recent study led by researchers from Jakarta State University and the Ministry of Marine Affairs and Fisheries has shown how fermenting agricultural waste like coconut pulp and rice bran using a natural yeast called Rhodotorula taiwanensis can significantly improve the growth and nutritional quality of BSF maggots. These maggots are increasingly used as an eco-friendly alternative to expensive commercial fish feed.
Why Maggots?
Black soldier fly larvae are small, but they pack a powerful punch: they’re rich in protein and fats, grow rapidly, and thrive on organic waste. They’re not only a solution to the protein shortage but also help tackle the problem of food and agricultural waste.
Enter the Magic Yeast
The researchers experimented by mixing coconut pulp and rice bran with Rhodotorula taiwanensis, a yeast known for its ability to break down tough plant materials and even produce healthy fats. They tested two fermentation levels—30% and 40% yeast concentration—compared to a control with no added yeast.
The results were impressive. Maggots fed on the 40% fermented feed grew faster and bigger, reaching an average weight of 182 grams by day 16—more than double the control group. Their body length also increased, and they contained more fat (15.57%)—important for fish nutrition.
How It Works
The yeast acts like a microscopic chef. It breaks down fiber and complex sugars in the coconut pulp and rice bran into simpler, more digestible nutrients. It also adds natural antioxidants and antimicrobial compounds, making the feed not only more nutritious but also safer for the maggots and the fish that will eventually eat them.
A Win-Win for Farmers and the Planet
This method doesn’t just help fish farmers cut down on expensive commercial feeds—it also makes use of agricultural waste that would otherwise go unused. It’s a great example of circular economy in action, where waste becomes a resource.
With further development, this approach could support more sustainable aquaculture, reduce reliance on imported feed, and help ensure that affordable, high-quality protein is available for everyone.
Source:
Sari, Y., Rini Fahmi, M. ., & Sukmawati, D. (2025). Effect of fermented coconut waste and rice bran feed using Rhiodiotorula taiwanensis UNJCC Y-171 on Black Soldier Fly (BSF) larvae growth and proximate composition. Buitenzorg: Journal of Tropical Science, 2(1), 1–12. https://doi.org/10.70158/buitenzorg.v2i1.14