Accumulation of Astaxanthin Was Improved by the Nonmotile Cells of Haematococcus pluvialis

Feng Li,Minggang Cai,Jun Wang,Yu An,Mingwei Lin,Shaoting Wu,Xianghu Huang,Xuehong Zheng

doi:10.1155/2019/8101762

Feng Li, Minggang Cai + Show 6 more

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https://doi.org/10.1155/2019/8101762

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Abstract

The current commercial production of natural astaxanthin is mainly carried out using Haematococcus pluvialis vegetative cells in the “two-stage” batch mode. The motile vegetative cells are more sensitive to stress than nonmotile vegetative cells, thereby affecting the overall astaxanthin productivity in H. pluvialis cultures. In this study, we compared the differences between motile cells and nonmotile cells in astaxanthin productivity, morphological changes, the mortality rate, and the diameter of the formed cysts. The experimental design was achieved by two different types H. pluvialis cell under continuous light of 80 μmol photons m−2 s−1 for a 9-day induction period. The highest astaxanthin concentration of 48.42 ± 3.13 mg L−1 was obtained in the nonmotile cell cultures with the highest the productivity of 5.04 ± 0.15 mg L−1 day−1, which was significantly higher than that in the motile cell cultures. The microscopic examination of cell morphological showed a large number of photooxidative damaged cells occurring in the motile cell cultures, resulting in higher cell mortality rate (22.2 ± 3.97%) than nonmotile cell cultures (9.6 ± 0.63%). In addition, the analysis results of cell diameter statistics indicated that nonmotile cells were more conducive to the formation of large astaxanthin-rich cysts than motile cells. In conclusion, the works presented here suggest that the accumulation of astaxanthin was significantly improved by nonmotile cells of H. pluvialis, which provided a possibility of optimizing the existing H. pluvialis cultivation strategy for the industrial production.

Highlights

Astaxanthin is a high-value red ketocarotenoid with powerful antioxidant capacity [1, 2] and widely used in nutraceuticals, aquaculture, cosmetics, food, and feed industries [3,4,5,6]
The ability of astaxanthin accumulation is the key parameter for evaluating the application potential of algae strains in H. pluvialis astaxanthin production
The value of astaxanthin productivity in the nonmotile cells cultures was ranged from 4.49 ± 0.39 to 5.04 ± 0.15 mg L−1 day−1 was Astaxanthin content (mg L−1) day−1 and the maximum value occurred on day 6

Summary

Introduction

Astaxanthin is a high-value red ketocarotenoid with powerful antioxidant capacity [1, 2] and widely used in nutraceuticals, aquaculture, cosmetics, food, and feed industries [3,4,5,6]. The common strategy for production of astaxanthin from H. pluvialis in industrial is “two-stage” batch method, consisting of a first step to sustain green vegetable cells rapid growth under favorable conditions (“green” stage) and a second step carried out by exposing the cells into stress conditions inducing astaxanthin accumulation (“red” stage) [9,10,11,12]. It has been reported that high temperature and high salt can enhance the accumulation of astaxanthin [15,16,17]. These stress factors may cause cell death, resulting in the fact that overall astaxanthin productivity in H. pluvialis cultures is low [18, 19]

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