Astaxanthin-Producing Green Microalga Haematococcus pluvialis: From Single Cell to High Value Commercial Products

Abstract

Many species of microalgae have been used as source of nutrient rich food, feed, and health promoting compounds. Among the commercially important microalgae, Haematococcus pluvialis is the richest source of natural astaxanthin which is considered as “super anti-oxidant.” Natural astaxanthin produced by H. pluvialis has significantly greater antioxidant capacity than the synthetic one. Astaxanthin has important applications in the nutraceuticals, cosmetics, food, and aquaculture industries. It is now evident that, astaxanthin can significantly reduce free radicals and oxidative stress and help human body maintain a healthy state. With extraordinary potency and increase in demand, astaxanthin is one of the high-value microalgal products of the future.This comprehensive review summarizes the most important aspects of the biology, biochemical composition, biosynthesis, and astaxanthin accumulation in the cells of H. pluvialis and its wide range of applications for humans and animals. In this paper, important and recent developments ranging from cultivation, harvest and postharvest bio-processing technologies to metabolic control and genetic engineering are reviewed in detail, focusing on biomass and astaxanthin production from this biotechnologically important microalga. Simultaneously, critical bottlenecks and major challenges in commercial scale production; current and prospective global market of H. pluvialis derived astaxanthin are also presented in a critical manner. A new biorefinery concept for H. pluvialis has been also suggested to guide toward economically sustainable approach for microalgae cultivation and processing. This report could serve as a useful guide to present current status of knowledge in the field and highlight key areas for future development of H. pluvialis astaxanthin technology and its large scale commercial implementation.

Recent Advances in Microalgal Bioactives for Food, Feed, and Healthcare Products: Commercial Potential, Market Space, and Sustainability

“…It has a seven‐fold higher antioxidant activity than other carotenoids such as β‐carotene (Gong & bassi, ). It protects the essential lipid components in the cell, especially the membrane phospholipids (Shah, Liang, Cheng, & Daroch, ). There are two oxygenated groups present on each ring structure in astaxanthin, which gives it enhanced antioxidant properties.…”

“…Astaxanthin also provides antioxidant properties to the cells and protects from atherosclerotic, neurodegenerative and cardiovascular diseases (http://www.oilgae.com/non_fuel_products/astaxanthin.html). Natural carotenoids such as astaxanthin can cross the blood–brain barrier and can exhibit antioxidant properties and are beneficial in case of neurodegenerative disorders (Shah et al., ). Apart from acting as an antioxidant, astaxanthin is also an anti‐inflammatory component, enhancing the antibody (IgA, IgM, and IgG) production (Deniz, García‐Vaquero, & Imamoglu, ).…”

Extraction of astaxanthin from microalgae: process design and economic feasibility study

“…The main operating parameters are the bead filling, bead density, bead diameter, the speed of the agitation and the feed rate [16]. Taking into consideration the high viscosity of the slurry entering the bead miller, ceramic beads specifically alumina (ρ = 3,8 kg/m 3 ) were used in this study [17]. The optimal bead diameter and the volume fraction of bead loading were obtained from the literature and they were respectively: 0.5 mm and 60% [6].…”

Green microalgae biomolecule separations and recovery

“…Typically, a two-step cultivation process is used including accumulation of vegetative cells in optimal growth conditions followed by exposure to suboptimal environmental or nutrient stresses (Sarada et al 2002). During stress conditions, vegetative cells become hematocysts and accumulate astaxanthin to 1.5-3.0% dry weight (Shah et al 2016). The cells are then harvested via settling and centrifugation, disrupted rapidly with homogenization or ultrasonication to retain astaxanthin integrity, and cracked or pulverized to enhance extraction and recovery.…”