![]() ![]() Moreover, this method is more environmentally friendly as the enzymes, salts, and solvents can be recycled for reuse. This developed method may replace column chromatography or gel filtration with a few steps of processes, simple equipment, and minimum volumes of solvents. We further combined both enzyme- and salt-assisted methods and applied them to 3 S,3′ S-AST isolation from yeast, and highly purified 3 S,3′ S-AST products were obtained from this simple preparation. Carotenoid standards and various salts were used to monitor and modify the salt-assisted liquid-liquid extraction (SALLE), and AST was isolated successfully from carotenoid mixtures by forming complexes with metal ions. The extraction yield of 3 S,3′ S-AST was enhanced with an enzymatic cell wall disruption. In this study, we developed a highly efficient method for extracting and isolating 3 S,3′ S-AST from the genetically modified yeast without gel column chromatography and gel filtration. Therefore, it is urgent to establish an optimal preparation method for yeast-produced AST. In addition, rats with lung cancer that were fed the AST products showed inhibition of metastasis in cancer cells and an increased survival rate. The two animal models, zebrafish and rat, showed no significant toxic effects. In DPPH scavenging analysis, the AST products showed a significant antioxidant ability. The investigation of the safety of the AST products from yeast was achieved by in vitro assay and animal models. The yeast expressed both enzymes, and the resulting AST could respectively yield up to 3.125 and 5.701 mg/g DCW in a different medium, which turned it into the highest-produced microorganism in nature. Two enzymes from algae, β-carotene ketolase ( bkt) and hydroxylase ( hpchyb), were included in the yeast for constructing a better AST biosynthesis pathway. reported that a strain of genetically modified yeast ( Kluyveromyces marxianus) obtained the ability of 3 S,3′ S-AST production without other optical isomers. The strain resulted in the production of 5.8 mg/g DCW AST. ![]() ![]() Previous studies have reported that the construction of the biosynthesis pathway for AST production was established in a strain of Escherichia coli that has been considered GRAS (Generally Recognized as Safe) and has been in commercial use in food industries. To reach and keep up with the increasing demand for the market of AST, efforts have been made to enhance the production of AST in some microorganisms through metabolic engineering. Due to low bioavailability, the synthetic product is currently not allowed for human consumption because of safety issues. The antioxidant activity of the (3 S,3′ S) stereoisomer is higher than that of (3 R,3′ R), while the lowest antioxidant activity is found in the (3 R,3′ S) meso-form. The structures of the AST isomers show distinct characteristics and, consequently, differences in bioactivity. The synthetic AST is composed of a ratio of approximately 1:2:1 of (3 S,3′ S), (3 R,3′ R), and (3 R,3′ S). ![]() Chemically, an efficient organic synthesis pathway from isophorone, cis-3-methyl-2-penten-4-yn-1-ol, and a symmetrical dialdehyde has been discovered and applied to industrial production. Due to a high production, it was the commercial microalgae that was first applied for industrial-scale production of natural AST. pluvialis is considered the best resource of natural AST, and it contains 2–4% AST in Haematococcus under some severe conditions. The (3 S,3′ S-) isomer is the major component in Haematococcus pluvialis. This new combination preparation may replace previous methods and has the potential to be scaled up in the manufacture of high-purity 3 S,3′ S-AST from low-value bioresources of raw materials to high-value products in the food and/or drug industries with lower cost and simple equipment.ĪST occurs as three optical isomers, (3 S,3′ S), (3 R,3′ R), and (3 R,3′ S) ( Figure 1A–D), which show compositional differences and are found in various natural sources. In the oxygen radical antioxidant capacity (ORAC) assay, the antioxidant capacity of high-purity 3 S,3′ S-AST products were 18.3 times higher than that of the original raw material extract. The highest yield of 3 S,3′ S-AST indicated that FoodPro ® CBL for yeast cell walls hydrolysis could significantly enhance extraction and obtain, with the help of SALLE procedure, quantified 3 S,3′ S-AST over 99% in purity through cation chelation. A highly efficient methodology for bioactive ingredient 3 S,3′ S-astaxanthin (3 S,3′ S-AST) preparation from genetically modified yeast ( Kluyveromyces marxianus) with a combination of enzyme-assisted extraction and salt-assisted liquid-liquid extraction (SALLE) was achieved. ![]()
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