• ALGAE
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• v.28 no.2
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• pp.131-147
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• 2013

Major progress has been made in the past decade towards understanding of the biosynthesis of red carotenoid astaxanthin and its roles in stress response while exploiting microalgae-based astaxanthin as a potent antioxidant for human health and as a coloring agent for aquaculture applications. In this review, astaxanthin-producing green microalgae are briefly summarized with Haematococcus pluvialis and Chlorella zofingiensis recognized to be the most popular astaxanthin-producers. Two distinct pathways for astaxanthin synthesis along with associated cellular, physiological, and biochemical changes are elucidated using H. pluvialis and C. zofingiensis as the model systems. Interactions between astaxanthin biosynthesis and photosynthesis, fatty acid biosynthesis and enzymatic defense systems are described in the context of multiple lines of defense mechanisms working in concert against photooxidative stress. Major pros and cons of mass cultivation of H. pluvialis and C. zofingiensis in phototrophic, heterotrophic, and mixotrophic culture modes are analyzed. Recent progress in genetic engineering of plants and microalgae for astaxanthin production is presented. Future advancement in microalgal astaxanthin research will depend largely on genome sequencing of H. pluvialis and C. zofingiensis and genetic toolbox development. Continuous effort along the heterotrophic-phototrophic culture mode could lead to major expansion of the microalgal astaxanthin industry.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.484-489
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• 2017

Lilies as cut flowers are one of the most popular ornamental plants in South Korea. It is necessary to develop lily cultivars with high qualities. Therefore, highly efficient propagation systems are needed following release of elite cultivars. In this study, we used taurine treatment to improve the growth conditions including shoot and bulb formation, fresh weight gain, and reduction of rooting and browning. We experimentally evaluated the effect of taurine as a growth stimulator, at concentrations of 0, 2.5, 5, 10, 15 and 20 mg/l. The results showed that 20 mg of taurine enhanced shoot formation by 85% and increased fresh weight 5.5-fold, which was higher than the approximately four-fold increase in the control. In addition, multiple bulb formation rate was increased by 80% and rooting by 82% following exposure to 20 mg/l of taurine. The efficiency of taurine treatment was higher than that of control with 50% multiple bulb formation rate and 60% rooting rate. The browning was 10.6% at 2.5 mg/l of taurine when compared with 0.8% at 20 mg/l. Taurine showed a positive effect on the overall growth of lily plants in terms of increased fresh weight, shoot formation rate, rooting, and formation of multiple bulbs, indicating that taurine can be used as an alternative to amino acids or as an antioxidant such as citrate and vitamin C in plant tissue culture.