Optimization of acidic extraction of astaxanthin from Phaffia rhodozyma

Abstract

Optimization of a process for extracting astaxanthin from Phaffia rhodozyma by acidic method was investigated, regarding several extraction factors such as acids, organic solvents, temperature and time. Fractional factorial design, central composite design and response surface methodology were used to derive a statistically optimal model, which corresponded to the following optimal condition: concentration of lactic acid at 5.55 mol/L, ratio of ethanol to yeast dry weight at 20.25 ml/g, temperature for cell-disruption at 30 °C, and extraction time for 3 min. Under this condition, astaxanthin and the total carotenoids could be extracted in amounts of 1294.7 µg/g and 1516.0 µg/g, respectively. This acidic method has advantages such as high extraction efficiency, low chemical toxicity and no special requirement of instruments. Therefore, it might be a more feasible and practical method for industrial practice.

Study on the relationship between intracellular metabolites and astaxanthin accumulation during Phaffia rhodozyma fermentation

“…Next, 5 mL of ethanol was used to extract carotenoid. Astaxanthin concentration was detected at a wavelength of 474 nm [32].…”

Astaxanthin: structural and functional aspects

“…The yeast Xanthophyllomyces dendrorhous (Phaffia rhodozyma) and the microalgae Haematococcus pluvialis (H. pluvialis) are known as the main microorganisms capable of synthesizing astaxanthin 27 . A number of studies have been carried out to determine the best conditions to synthesize and extract astaxanthin from these microorganisms [28][29][30] . H. pluvialis accumulates higher amounts of ketocarotenoids in cytoplasmic lipid vesicles and has been reported to be the richest source of natural astaxanthin 14 , reaching 9.2mg/g cell 27 .…”

An improved process for cell disruption and astaxanthin extraction from Phaffia rhodozyma

“…Although autolysis could disrupt yeast cell wall and extract astaxanthin, the productivity was still low for industrial use. Cell disruption by organic solvent such as dimethyl sulfoxide can give a high yield of astaxanthin, however, product security is a considerable problem due to the content of toxic solvent (Ni et al 2004).…”

“…Phaffia rhodozyme 7B12 was maintained and activated on yeast/malt (YM) agar slants containing (/l) 10.0 g glucose, 5.0 g bacto-peptone, 3.0 g malt extract, 3.0 g yeast extract and 20.0 g agar, and inoculated into a 250-ml flask containing 30 ml YM broth and cultured on a rotary shaker at 22°C, 200 rev/min for 72 h (Ni et al 2008).…”