Monoraphidium sp. HDMA-20 is a new potential source of α-linolenic acid and eicosatetraenoic acid

Abstract

Background ω-3 polyunsaturated fatty acids (PUFAs) are synthesized from α-Linolenic acid (ALA, C18:3ω3) and play important roles in anti-inflammatory and antioxidant responses in mammal cells. ALA is an essential fatty acid which cannot be produced within the human body and must be acquired through diet. The purpose of this study was to evaluate the potential of a novel microalgal strain (HDMA-20) as a source of ω-3 PUFAs including ALA and eicosatetraenoic acid (ETA, C20:4ω3). Method Phylogenetic Neighbor-Joining analysis based on 18S ribosomal DNA sequence was used to identify the microalga strain HDMA-20. Autotrophic condition was chosen to cultivate HDMA-20 to reduce the cultivation cost. GC-MS was used to determine the fatty acid composition of HDMA-20 lipid. Results A microalgal strain (HDMA-20) from Lake Chengfeng (Daqing, Heilongjiang province, China) was found to accumulate high content of ω-3 PUFAs (63.4% of total lipid), with ALA and eicosatetraenoic acid (ETA, C20:4ω3) accounting for 35.4 and 9.6% of total lipid, respectively. Phylogenetic analysis based on 18S ribosomal DNA sequences suggested that the HDMA-20 belonged to genus Monoraphidium (Selenastraceae, Sphaeropleales) and its 18S rDNA sequence information turned out to be new molecular record of Monoraphidium species. The biomass productivity and lipid content of HDMA-20 were also investigated under autotrophic condition. The biomass productivity of HDMA-20 reached 36.3 mg L − 1 day − 1 , and the lipid contents was 22.6% of dry weight. Conclusion HDMA-20 not only represent an additional source of ALA, but also a totally new source of ETA. The high content of ω-3 PUFAs, especially ALA, of HDMA-20, makes it suitable as a source of nutrition supplements for human health. In addition, HDMA-20 exhibited good properties in growth and lipid accumulation, implying its potential for cost-effective ω-3 PUFAs production in future.

Nutrient Deprivation Mobilizes the Production of Unique Tocopherols as a Stress-Promoting Response in a New Indigenous Isolate Monoraphidium sp.

“…KMN5; 13.0 mg L −1 d −1 ) (Tale et al, 2014), Monoraphidium sp. HDMA-20; 36.3 mg L −1 d −1 ) (Lin et al, 2019). A recent study by our group involving Parachlorella kessleri subjected to a nitrogen stress condition demonstrates that the photosynthetic activity ceases affecting the phosphorus absorption, and cells shut down energy-expensive metabolisms, such as protein synthesis, by diverting the carbon flux to energy storage metabolites, such as lipids and/or carbohydrates (Shaikh et al, 2019).…”

Potential of the biodegradability and characteristics of bio-plastic from microalgae residues

“…Третім видом, виявленим у зразках води, був Monoraphidium sp. Клітини цієї зеленої мікроводорості мають викривлену форму та утворюють колонії з кількох клітин (Lin et al, 2019). Рибний ставок можна вважати хорошим місцезростанням для Monoraphidium sp., оскільки у його воді міститься багато поживних речовин, таких як азот, фосфор і залізо.…”

Construction of Eicosatetraenoic Acid Producing Cell Factory by Genetic Engineering of Mucor circinelloides

“…Since ω-3 PUFAs cannot be de novo synthesized by mammals, they must be obtained through diet. Due to the vital role of eicosapentaenoic acid (EPA, 20:5 ω-3) and docosahexaenoic acid (DHA, 22:6 ω-3) in human health, they received growing attention and were well-studied in recent years [3,4]. In addition, stearidonic acid (SDA, 18:4 ω-3) and docosapentaenoic acid (DPA, 22:5 ω-3) have been developed and utilized [5][6][7][8].…”

“…Furthermore, it has been known as a metabolic precursor of EPA. Various research has been conducted on the health benefit of EPA and DHA, while the detailed biochemical function of ETA has rarely been reported since it is a rare source and cannot be easily purified [4]. Early studies indicated that ETA could modulate eicosanoid production in mammalian cell systems and works as an active molecule responsible for anti-inflammatory responses [1,10].…”

“…Additionally, certain fungi and microalgae are capable of synthesizing ETA, the ETA content of Monoraphidium sp. HDMA-20 can reach 9.6% of its total lipid when this strain is cultured under autotrophic conditions for 18 days [4]. Thus, the natural source of ETA remains to be explored.…”