Food additives made from aquatic plants could reduce the need for fertiliser

A startup is turning duckweed into a high-protein food additive that could replace foods that are grown using large amounts of fertiliser

Spotted: According to the UN’s Food and Agricultural Organization, agriculture is the biggest source of water pollution. This is largely due to the excess nutrients from fertilisers that run off from fields into rivers, lakes, oceans, and groundwater sources. This excess of nutrients like nitrogen and phosphorus leads to algae blooms, which produce harmful toxins, lower the oxygen content of the water, clog the gills of fish and invertebrates, and smother corals and submerged aquatic vegetation.

One solution is to use less fertiliser or to grow food that does not require fertiliser. The latter is the direction being taken by microTERRA, a startup that grows the aquatic plant lemna, or duckweed, for use as an ingredient in plant-based foods. Lemna is very high in protein, and microTERRA processes the plant into an ingredient that can replace crops like soy for use in both pet and human food products.

The lemna can also grow in water with high concentrations of nitrogen and phosphorus – major components of fish waste. This means that not only can the lemna be grown in water already polluted from fish farms and fertilizer runoff – it can also help to clean that water. In fact, microTERRA grows its lemna in existing fish farms, creating a sustainable model with little capital expenditure by the company. 

According to microTERRA Co-founder and CEO Marissa Cuevas, the company has a waiting list of farmers who want to work with them. However, because they cannot yet produce high volumes, they are focusing on the premium pet food market, saying, “We thought it’s easy and doesn’t require premium quality ingredients (no one minds if there’s a bit of green coloring remaining in the lemna meal).” But she adds that demand is there for other uses, “We have recently seen a lot of excitement from plant-based restaurants, because our new ingredient offers a playground for them to build their amazing creations.”  

Lemna is just one of a number of water-grown plants that are being developed to deliver improved sustainability. Some of the most recent innovations we have seen in this area involve seaweed, including edible food packaging made from kelp and a seaweed-based lipstick. 

Written By: Lisa Magloff