She is Turning Rotten Fruit into the Future of African Fish Farming

In the bustling markets of Dar es Salaam, mountains of organic waste, rotting mangoes, discarded vegetable stalks, and fruit peels are a common sight. To most, this is an environmental hazard and a source of foul smell. To Diana Orembe, a young Tanzanian microbiologist, this waste is "black gold." Diana realised that the biggest barrier for fish farmers in Tanzania wasn't a lack of water or demand; it was the cost of feed. Traditional fish feed relies heavily on soy and fishmeal, which are often imported, expensive, and environmentally destructive. Diana’s vision was to create a high-protein alternative using the one thing Tanzania has in abundance: organic waste.

The journey to founding NovFeed began in the lab. Diana spent years researching how specific microbes could break down organic waste and transform it into a nutrient-rich protein source. This wasn't just a simple composting process; it was a high-tech "bio-refinery." By using a proprietary blend of bacteria and fungi, NovFeed converts food waste into a concentrated protein powder that contains all the essential amino acids a tilapia or catfish needs to grow. Speaking to the Milken Institute after winning a prestigious global prize, Diana explained that her goal was to create a "circular economy" where nothing is wasted, and everything is reused to create value.

The transition from a laboratory scientist to a biotech entrepreneur was challenging. Diana had to prove to sceptical farmers that "insect and microbe-based" feed was just as effective, if not better, than the expensive soy-based pellets they were used to. She conducted rigorous trials, showing that fish, fed with NovFeed grew faster and had a higher survival rate. The results were undeniable. Not only was her feed 30% cheaper for the farmers, but it also helped reduce the carbon footprint of aquaculture by diverting waste from landfills and reducing the pressure on wild fish stocks used for fishmeal.

Her innovation caught the attention of the global stage. In 2023, NovFeed won the $1 million Milken-Motsepe Prize in AgriTech, beating out hundreds of competitors from around the world. This massive injection of capital allowed Diana to move from a small pilot plant to a commercial-scale facility. By 2025, NovFeed was processing tons of organic waste every day, providing a steady supply of affordable protein to thousands of smallholder fish farmers across East Africa. According to a 2026 feature in The EastAfrican, Diana’s work has been pivotal in making aquaculture a viable business for Tanzanian youth, who previously found the entry costs too high.

Today, Diana Orembe is more than just a scientist; she is a leader in the African "Bio-Revolution." She is actively working on expanding NovFeed’s technology to create animal feed for poultry and pigs, further diversifying the impact of her circular economy model. She remains a firm believer that the answers to Africa's food security challenges are hidden in its own biodiversity. As she often tells her team in Dar es Salaam, "Nature has the technology; we just need to provide the right environment for it to work."

Lessons for Budding Makers

Diana Orembe’s success as a biotech maker offers two profound lessons:

1. Value is Often Hidden in Waste: Many of the world’s most successful "green" businesses don't create new materials; they find better ways to use what we already throw away. If you are looking for a project, look at the "trash" in your community; there is a high chance a scientific process can turn it into a high-value product.
2. Data Wins Arguments: Diana didn't just tell farmers her feed was better; she showed them the growth charts. When you are introducing a disruptive technology (like microbe-based feed), your most powerful tool is a well-documented pilot study. Prove that your invention makes your customer more money, and the world will beat a path to your door.