Selenium Accumulation in Unicellular Green Alga Chlorella vulgaris and Its Effects on Antioxidant Enzymes and Content of Photosynthetic Pigments

Abstract

The aim of the present study was to investigate selenite effects in the unicellular green algae Chlorella vulgaris as a primary producer and the relationship with intracellular bioaccumulation. The effects of selenite were evaluated by measuring the effect of different selenite concentrations on algal growth during a 144 h exposure period. It was found that lower Se concentrations (≤75 mg L−1) positively promoted C. vulgaris growth and acted as antioxidant by inhibiting lipid peroxidation (LPO) and intracellular reactive oxygen species (ROS). The antioxidative effect was associated with an increase in guaiacol peroxidase (GPX), catalase (CAT), superoxide dismutase (SOD) and photosynthetic pigments. Meanwhile, significant increase in the cell growth rate and organic Se content was also detected in the algae. In contrast, these changes were opposite in C. vulgaris exposed to Se higher than 100 mg L−1. The antioxidation and toxicity appeared to be correlated to Se bioaccumulation, which suggests the appropriate concentration of Se in the media accumulation of C. vulgaris should be 75 mg L−1. Taken together, C. vulgaris possesses tolerance to Se, and Se-Chlorella could be developed as antioxidative food for aquaculture and human health.

Antioxidant modulation in response to selenium induced oxidative stress in unicellular cyanobacterium Synechococcus elongatus PCC 7942

“…The induction of antioxidants in response to enhanced ROS production is generally proportional to the duration and severity of the stress applied to algal cultures (Sun et al, 2014). In our study, it was observed that Se accumulation resulted in higher activities of SOD, POX, GPX and GR after 72 h ( Table 2).…”

“…Algae Ulva species and Chlorella vulgaris showed induced expression of SOD enzyme activity in response to ROS production caused by different Se compounds (Schiavon et al, 2012;Sun et al, 2014). The production of H 2 O 2 can be reduced to water by catalase, ascorbate peroxidase and peroxidase or through the ascorbate (AsA)-GSH cycle (Feng and Wei, 2012).…”

Chlorella vulgaris as a Source of Essential Fatty Acids and Micronutrients: A Brief Commentary

“…Also, Chlorella extracts modulated oxidative and inflammatory responses from human peripheral blood mononuclear cells stimulated by heat-killed P. acnes [19]. Sun et al (2014) proposed the use of selenium-enriched C. vulgaris cultures as means to induce bioaccumulation, producing antioxidant-rich biomass with applications in agriculture and human diet. Data showed that C. vulgaris is satisfactorily tolerant to selenium accumulation in culture [42].…”

“…Sun et al (2014) proposed the use of selenium-enriched C. vulgaris cultures as means to induce bioaccumulation, producing antioxidant-rich biomass with applications in agriculture and human diet. Data showed that C. vulgaris is satisfactorily tolerant to selenium accumulation in culture [42].…”

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“…Yellow catfish restricted to freshwater habitats has become a favorite food fish due to its excellent meat quality; and has become an important freshwater aquaculture species due to its high commercial value (Sun, Zhong, Huang, & Yang, 2014). However, many diseases have become the restricted factor for catfish farming development.…”