Identification and characterization of <italic>Dunaliella salina</italic> OH214 strain newly isolated from a saltpan in Korea

Abstract

Carotenoids are effective antioxidants that are found in various photosynthetic organisms. Marine microalgae are an advantageous bioresource for carotenoid production because they do not compete with other crops for freshwater and arable land. This study reports a newly isolated Dunaliella strain from the Geumhong Saltpan on Yeongjong Island, West Sea, Korea. The new strain was isolated and classified as Dunaliella salina through phylogenetic analysis and was named the OH214 strain (Deposit ID: KCTC14434BP). The newly isolated strain can survive in a wide range of NaCl concentrations (0.3−5.0 M NaCl), but grows well in 0.6 to 1.5 M NaCl culture medium. Under high-light conditions (500 ± 10 μmol photons m&lt;sup&gt;-2&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;), the cells accumulated three times more β-carotene than under low-light conditions (50 ± 5 μmol photons m&lt;sup&gt;-2&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;). The cells accumulated 2.5-fold more β-carotene under nitrogen-deficient (1 mM KNO&lt;sub&gt;3&lt;/sub&gt;) conditions (3.24 ± 0.36 μg 106 cells&lt;sup&gt;-1&lt;/sup&gt;) than in nitrogen-sufficient conditions (&gt;5 mM KNO&lt;sub&gt;3&lt;/sub&gt;). The lutein content under nitrogen-deficient conditions (1.73 ± 0.09 μg 106 cells&lt;sup&gt;-1&lt;/sup&gt;) was more than 24% higher than that under nitrogen-sufficient conditions. Under the optimized culture condition for carotenoid induction using natural seawater, D. salina OH214 strain produced 7.97 ± 0.09 mg g DCW&lt;sup&gt;-1&lt;/sup&gt; of β-carotene and 4.65 ± 0.18 mg g DCW&lt;sup&gt;-1&lt;/sup&gt; of lutein, respectively. We propose that this new microalga is a promising strain for the simultaneous production of β-carotene and lutein.

Deciphering the β‐carotene hyperaccumulation in Dunaliella by the comprehensive analysis of Dunaliella salina and Dunaliella tertiolecta under high light conditions

“…In this study, we hypothesized that the two mechanisms mentioned above are equally involved in β‐carotene hyperaccumulation in D. salina , and that de novo biosynthesis coincides with sequestration in βCGs. To gain insights into the hyperaccumulation of β‐carotene, we compared D. salina CCAP19/18, which is a β‐carotene hyperaccumulating strain, with a noncarotenogenic species Dunaliella tertiolecta strain CCAP19/42 (Kim et al, 2010, 2022). Morphology and physiology were compared under β‐carotene accumulating conditions, focusing on the initiation of carotenogenesis in D. salina by light stress (Ben‐Amotz & Avron, 1983; Park et al, 2015).…”

Qualitative and quantitative evaluation of microalgal biomass using portable attenuated total reflectance‐Fourier transform infrared spectroscopy and machine learning analytics

“…Microalgae are a diverse group of microorganisms that use carbon dioxide and light to synthesize their food and produce oxygen. They do not compete with plants for freshwater resources or arable land because they can grow in brackish water, [1][2][3] wastewater, and non-arable land. [4][5][6][7][8] These characteristics make them suitable for the production of biomass that can be used as bioenergy, [9][10][11][12] feed, 13,14 fertilizers, [15][16][17] food, 18,19 and pharmaceutical compound manufacturing.…”