Progress in the cultivation of diatoms using organic carbon sources

Diatoms are ideal aquaculture baits because they are not only rich in products with added value, such as eicosapentaenoic acid (EPA), docosahexaenoic acid, chrysolaminarin, and fucoxanthin (Fx) but also substantial primary producers in aquaculture. It is difficult to cultivate diatoms at a high density using traditional photoautotrophy. For improving diatom growth rate, biomass, and metabolites, mixotrophy and heterotrophy employing organic carbon sources are promising. However, preparing a conventional single organic carbon source is complicated and costly. This paper reviews the diatom species that can utilize organic carbon, the types of organic carbon used by diatoms (saccharides, alcohols, carboxylic acids, nitrogenous organic carbon, phenols), and the main bottlenecks and technical means of diatom heterotrophy and mixotrophy from an aquaculture perspective. For the first time, the impact of fermented feed on diatom culture was discussed to guide the development of a more efficient and practical nutrient supplement to promote.