Isolation and Characterization of a Xanthophyll Aberrant Mutant of the Green Alga Nannochloropsis oculata

Abstract

Novel mutants (xan1 and xan2) of the unicellular green alga Nannochloropsis oculata are impaired in xanthophyll biosynthesis, thereby producing aberrant levels of xanthophylls. High-performance liquid chromatography (HPLC) analysis revealed that the xan1 and xan2 mutants have double the violaxanthin (V) content, but have significantly decreased lutein content in their cells compared to the wild type. Furthermore, these mutants contain two to three times more zeaxanthin than the wild type under low light (LL) growth conditions. However, this xanthophyll aberration in N. oculata did not affect the normal growth and the major cellular chemical composition of the xan1 strain. The xanthophyll pool size of the LL-grown mutant was 1.8-fold greater than that of the wild type. Under high light (HL) growth conditions, V content was substantially decreased in both the mutant and wild types because of the epoxidation state of the xanthophylls. Under LL growth conditions, the deepoxidation states of the xanthophyll pool sizes were 0.1 and 1.2 in the wild type and the mutant, respectively. However, the deepoxidation states of the xanthophyll pool sizes were 0.78 in the wild type and 0.87 in the mutant under HL growth conditions. We observed that the level of one of the commercially important xanthophylls, zeaxanthin, was higher in the mutant than in the wild type under all culture conditions. This mutant is discussed in terms of its commercial value and potential utilization by the algal biotechnology industry for the production of zeaxanthin.

Potential and properties of marine microalgae Nannochloropsis oculata as biomass fuel feedstock

“…It plays significant roles in the global carbon and mineral cycles [29]. This microalgae contains rich proteins, pigments, and polyunsaturated fatty acids [26,30,31], and it is commonly used in aquaculture as feed [32,33]. In recent years, Nannochloropsis has been proposed as an excellent candidate for biofuel production [34,35].…”

Algae Polar Lipids Characterized by Online Liquid Chromatography Coupled with Hybrid Linear Quadrupole Ion Trap/Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

“…We focus initially on Nannochloropsis oculata (green algae) because of its relatively high oil yield (40–60%) . Most prior lipid characterization methods are bulk or indirect analyses and cannot resolve and identify intact molecular structures. , Here, we combine online liquid chromatography (LC) with electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) and tandem mass spectrometry (MS/MS) to resolve and identify lipid elemental compositions, C c H h N n O o P p S s , head groups, fatty acid chain lengths, and unsaturation of polar lipids from green algae, as a first step in the molecular level characterization of wild type and genetically engineered (mutant) algae , of improved growth rate and lipid yield for the production of algal fuels…”

Anti-Inflammatory and Anticancer Effects of Microalgal Carotenoids

“…Regarding microalgae, this xanthophyll has been obtained from the cyanobacteria Synechocystis sp. and Microcystis aeruginosa [42], as well as the microalgae Nannochloropsis oculata (Ochrophyta, Eustigmatophyceae) [43], Chloroidium saccharophilum (formerly Chlorella saccharophila) [44], and Dunaliella sp. [45], and red algae such as Porphyridium purpureum (formerly Porphyridium cruentum) (Rhodophyta) [35], Phaeodactylum tricornutum (Bacillariophyta) [46], or Heterosigma akashiwo (Ochrophyta, Raphidophyceae) [47].…”