Effects of Different Nitrogen Concentrations on Co-Production of Fucoxanthin and Fatty Acids in Conticribra weissflogii

Abstract

Fucoxanthin and fatty acids are active substances that are beneficial to the growth and immunity of humans and aquatic animals. However, relatively few species have been exploited for fucoxanthin and fatty acids in the industry. At the same time, due to its low extract content, poor stability, high production cost, and serious seasonal and regional limitations, the industry cannot normally meet the greater demand of the international market. Therefore, this experiment seeks to improve the fucoxanthin and fatty acid content of C. weissflogii by adjusting the nitrogen concentration in the culture medium. It was found that when the nitrogen concentration was 150 mg L−1, the cell number was 1.5 × 106 cell mL−1, and the average biomass was 0.75 g L−1. The mean value of carotenoid concentration was 2.179 mg L−1. The average concentration of fucoxanthin was 1.547 mg g−1. When the nitrogen concentration was 75 mg L−1, the fatty acid content reached its highest. By adjusting the concentration of nitrogen, the contents of fucoxanthin and fatty acids were increased. The results provided a theoretical basis for commercial extraction of fucoxanthin and fatty acids and further promoted the industrialization of fucoxanthin and fatty acids.

Understanding the Impact of Nitrogen Availability: A Limiting Factor for Enhancing Fucoxanthin Productivity in Microalgae Cultivation

“…Consistent with previous studies, the results indicated that nitrogen availability considerably influenced the physiological characteristics, including growth performance, biomass, and photosynthetic pigment production (Figure 1). Previously, the growth of Conticribra weissflogii and P. tricornutum was suppressed in the media without nitrogen supply [28,29], while Nitzchia sp. biomass was greatly reduced under limited nitrogen conditions [24].…”

Effect of Iron Concentration on the Co-Production of Fucoxanthin and Fatty Acids in Conticribra weissflogii

“…The C. weissflogii strain [ 15 ] used in this study was isolated from a shrimp pond in Southern China and preserved at the Laboratory of Algae Resource Development and Aquaculture Environmental Ecological Restoration of Guangdong Ocean University. This strain was grown autotrophically at a temperature of 25 °C in a modified F/2 medium, which contained NaNO 3 (75 mg), KH 2 PO 4 (5 mg), Na 2 SiO 3 -9H 2 O (20 mg), F/2 trace element solution (1 mL), and F/2 vitamin solution (1 mL) per liter of double-distilled water.…”

“…The prepared samples were analyzed with an Agilent 7890A gas chromatograph with the parameters and measurement procedures described in the authors’ previous studies [ 15 ]. A single fatty acid methyl ester standard solution and a fatty acid methyl ester mixed standard solution were injected into the gas chromatograph, and the peaks were characterized.…”

“…Conticribra weissflogii is a typical diatom that is easy to culture, has a fast growth rate, and is considered a potential cell factory for the production of fucoxanthin and unsaturated fatty acids [ 15 , 16 ]. Iron is an essential trace element for microalga growth, enzymatic reactions, nitrogen metabolism, and chlorophyll synthesis [ 17 ], and iron deficiency or excess inhibits the productivity of microalga cells [ 18 , 19 ].…”

Effects of Temperature, Light and Salt on the Production of Fucoxanthin from Conticribra weissflogii

“…Stock cultures of C. weissflogi were maintained at 25 ± 1 °C under a continuous light intensity of 30 μmol m −2 s −1 in 1 L flasks. A modified version of F/2 media was used, and the detailed formulation can be found in our recent study [ 31 ]. We centrifuged and collected 10-day-old algal cells for experiments.…”