EVALUATING THE POTENTIAL OF USING FOOD-GRADE WASTES TO ENHANCE PRODUCTIVITY OF MIXOTROPHIC SPECIES OF ALGAE.

Abstract

Microalgae industries can produce a large variety of valuable products but are limited by high production costs. Mixotrophic growth, when paired with high-nutrient waste products, provides a solution which can reduce costs and increase the productivity of these industries. This study screened six microalgae species which are typically used in aquaculture, with the goal of optimizing mixotrophic growth when supported by food-grade wastes. While all three wastes could support some algae growth, only whey permeate enhanced growth rates and yield. To evaluate changes in biomass and cell quotas, Tetraselmis suecica was grown on a larger scale with 1% whey permeate. Mixotrophic growth of T. suecica resulted in down-regulation of photosynthesis. This down-regulation did not occur with the addition of 1g/L of bicarbonate. Increasing the phosphorous and carbon available to T. suecica through bicarbonate and whey permeate additions significantly increased growth rates and biomass yields.