L-Carnitine supplementation improved population growth, photosynthetic pigment synthesis and antioxidant activity of marine Chlorella sp.
Sen Wang, Yuke Chen, Abdallah Ghonimy, Ting Yu, Yongsheng Gao, Zhenchao Wu, Qiuju Wang, Dongming Zhang
Abstract
High nutritive microalgae is a key factor that affecting the live feeds nutritional value and subsequently fish fry quality. We evaluated the effect of l-carnitine supplementation level on the population growth, photosynthetic pigment biosynthesis, and antioxidant capability of the pigment-protein complexes in the marine Chlorella sp. Five different l-carnitine levels (0, 5, 50, 100, and 200 mg L−1) were supplemented in the microalgae media for 10 days. The results demonstrated that l-carnitine increased the population density and specific growth rate in LC 5 (P < 0.05). While the β-carotene and iron contents were elevated in LC 5 and LC 50 (P < 0.05). Apart from, chlorophyll a, chlorophyll b, and magnesium contents were higher in the LC 5 (P < 0.05). While LC 5 had higher metal chelation in pigment-protein complexes (P < 0.05). Meanwhile, psy and chld gene expressions were up-regulated in the LC 5 and LC 50 (P < 0.05). Taken together, LC 5 and LC 50 could improve the population growth, pigment synthesis, antioxidant capacity and up-regulate the relative expression levels of photosynthetic pigment synthesis genes in marine Chlorella sp. Therefore, l-carnitine has comprehensive effects on algae production.