| 摘要 |
As the richest source of astaxanthin, a natural antioxidant and coloring agent, the unicellular green alga, Haematococcus pluvialis, is being commercially exploited. A major constraint in the Haematococcus production system, however, is the thick, rigid cell walls associated with astaxanthin-rich cysts (or aplanospores). The thick walls prevent the extraction of cellular materials and consequently reduce the bioavailability of astaxanthin. Using a physical, chemical, or enzymatic method to disrupt the cell wall has proven to be very expensive and also introduce the risk of oxidation of astaxanthin by atmospheric oxygen The present invention provides a novel method for solving this problem by introducing two genetically modified Haematococcus pluvialis mutants. These two mutants, named as D 13-17 and N54-22, contain remarkably reduced amounts of cell wall materials, but retain the growth potential and ability to accumulate astaxanthin as high as the wild type strain. Organic solvent extraction efficiency assay has demonstrated that cellular astaxanthin can be more effectively and efficiently extracted from the cell wall-deficient mutants than from the wild type, suggesting that the mutants may provide better bioavailability of astaxanthin to humans and animals. The said mutants can be used for production of natural astaxanthin for human and animal consumption
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