Growth and Biochemical Composition Characteristics of Arthrospira platensis Induced by Simultaneous Nitrogen Deficiency and Seawater-Supplemented Medium in an Outdoor Raceway Pond in Winter.

Hualian Wu,Jinting Lv,Na Wang,Zishuo Chen,Tao Li,Wenzhou Xiang,Jiayi Wu,Houbo Wu

doi:10.3390/foods10122974

Abstract

Arthrospira platensis, a well-known cyanobacterium, is widely applied not only in human and animal nutrition but also in cosmetics for its high amounts of active products. The biochemical composition plays a key role in the application performance of the Arthrospira biomass. The present study aimed to evaluate the growth and biochemical composition characteristics of A. platensis, cultured with a nitrogen-free and seawater-supplemented medium in an outdoor raceway pond in winter. The results showed that the biomass yield could achieve 222.42 g m−2, and the carbohydrate content increased by 247% at the end of the culture period (26 d), compared with that of the starter culture. The daily and annual areal productivities were 3.96 g m−2 d−1 and 14.44 ton ha−1 yr−1 for biomass and 2.88 g m−2 d−1 and 10.53 ton ha−1 yr−1 for carbohydrates, respectively. On the contrary, a profound reduction was observed in protein, lipid, and pigment contents. Glucose, the main monosaccharide in the A. platensis biomass, increased from 77.81% to 93.75% of total monosaccharides. Based on these results, large-scale production of carbohydrate-rich A. platensis biomass was achieved via a low-cost culture, involving simultaneous nitrogen deficiency and supplementary seawater in winter.

Highlights

Arthrospira, known as Spirulina, is a multicellular and filamentous cyanobacterium that can adapt to different water environments, such as freshwater, brackish lakes, and alkaline saline lakes [1]
Freshwater A. platensis was successfully cultured in the medium with the nutrients supplemented by NaHCO3, FeSO4, H3PO4, and seawater in a raceway pond (Figure 1a)
CO2 was supplied to the A. platensis culture, in order to adjust the pH values between 8.3 and 9.5—most of the time, above 9 (Figure 1b)

Summary

Introduction

Arthrospira, known as Spirulina, is a multicellular and filamentous cyanobacterium that can adapt to different water environments, such as freshwater, brackish lakes, and alkaline saline lakes [1]. Arthrospira has drawn more and more attention in food supplements, animal feed additives, pharmaceutical products, and cosmetics, due to its high levels of natural products with nutritional and health benefits, such as protein, phycocyanin, polysaccharides, polyunsaturated fatty acids (PUFAs), pigments, and amino acids [2,3,4]. The growth and biochemical composition of Arthrospira were influenced by many factors, such as nutrients, temperature, light, and salinity [13,14,15]. Strategies for regulating these factors have been developed to increase the accumulation of high-value products in Arthrospira for different application purposes [16,17]. Little information is known about the combined effects of different environmental factors on the biochemical compositions of Arthrospira cultured in large-scale outdoor raceway ponds

Results

Discussion

Conclusion