Seeding Food Innovation - Awarded Project 2019

A win/win approach to bioremediation of food-grade waste-streams: conversion to high-value foodstuffs through algal cultivation

Project Description

Phytoplankton are excellent sources of nutrition, particularly omega-3 fatty acids such as eicosapentaenoic acid (EPA), protein, and antioxidant carotenoids. They are used worldwide for human dietary supplements and aquaculture feeds but production is limited by the energetic demands of cultivation. For many types of phytoplankton, these costs can be reduced significantly by supplying energy in the form of organic carbon. These forms are mixotrophic, meaning that they combine photosynthesis (harvesting light energy) with heterotrophy (acquiring carbon and/or energy from organic molecules—feeding). If the organic carbon is from a food-grade waste-stream, using it to cultivate phytoplankton is a win-win: the biomass can be harvested for human and animal consumption; and the nutrients that were in the waste-stream are recycled, reducing the burden on waste-water treatment facilities.

Food Innovation

Optimizing large-scale cultivation of phytoplankton proceeds slowly for lack of an objective way to compare yields between different strains and growth conditions. This project will apply techniques developed by oceanographers to estimate primary production in the world’s oceans to mixotrophic cultivation of phytoplankton. This involves measuring and maximizing an objective performance metric, which is the mass of the product (e.g. EPA) produced for a given energetic cost in providing light and regulating temperature. Mixotrophy results increases this yield factor.

Outcome

This project is a collaboration between researchers at Dalhousie, The National Research Council, and Nature’s Way of Canada, a producer of EPA-rich dietary supplements. It will screen local strains of phytoplankton for mixotrophic growth using two food-grade wastes, dairy whey and distillate tails, as sources of organic carbon and other nutrients. Strains that show a significant stimulation of growth will be characterized under a range of growth conditions designed to maximize production of EPA or EPA plus protein and carotenoids. The best candidate strains and growth conditions will be identified by comparing the yield factors. These strains will then be tested at commercial scale (1250 L) to evaluate the cost effectiveness of using the recycled wastes to produce EPA alone or EPA with protein and carotenoids. While there is already commercial production of EPA from algae, this approach is innovative in subsidizing the costs of cultivation by coupling it to the recycling of organic- and phosphorous-rich wastes. We anticipate that the project will initiate an industry shift in sourcing of EPA from fish and krill oils to cultivated algae.

Grantees:

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