Mixotrophic culture of bait microalgae for biomass and nutrients accumulation and their synergistic carbon metabolism

Microalgae cannot meet the bait demand for aquaculture due to light intensity limitation and other disadvantageous conditions. This research selected 6 mixotrophic microalgae, and the optimal strains and organic carbon were screened. The results showed that Thalassiosira pseudonana and Chlorella sp. are suitable for mixotrophic culture. The maximum cell density of Thalassiosira pseudonana was found to be 1.67 times than that of the photoautotrophic group when glycerol was added. The maximum cell density of Chlorella sp. with acetic acid was 1.69 times than that of the photoautotrophic group. When the concentration of acetic acid was 5.0 g center dot L-1 and the concentration of KNO3 was 0.2 g center dot L-1, the maximum biomass of Chlorella sp. could reach 3.54 x 107 cells center dot mL-1; the maximum biomass of Thalassiosira pseudonana was 5.53 x 106 cells center dot mL-1 with 10.0 g center dot L-1 glycerol and 0.2 g center dot L1 KNO3. Metabolomic analysis further revealed that mixotrophic bait microalgae could promote the accumulation of lipids and amino acids.

Automated summary

Microalgae cannot fulfill the bait demand for aquaculture due to limitations in light intensity and other unfavorable conditions. This study selected 6 mixotrophic microalgae and screened for the optimal strains and organic carbon sources. Thalassiosira pseudonana and Chlorella sp. were found to be suitable for mixotrophic culture. When glycerol was added, Thalassiosira pseudonana showed a 1.67-fold increase in maximum cell density compared to the photoautotrophic group, while Chlorella sp. exhibited a 1.69-fold increase with acetic acid. Metabolomic analysis revealed that mixotrophic bait microalgae could promote the accumulation of lipids and amino acids.