| Haematococcus pluvias is a single-cell green freshwater algae.In the whole life history of Haematococcus pluvias,it is divided into two stages: swimming vegetative growth and immobilized transformation of astaxanthin production: When the light intensity is very weak and the nitrogen and phosphorus salts are sufficient,the swimming green vegetative cells grow and develop.When the environment is not suitable,such as high temperature,high salt,high light or nutrient starvation,a large amount of astaxanthin will accumulate.Astaxanthin(axanthin),as a fat-soluble ketone carotenoid,is also called metaxanthin or astaxanthin.It is classified as a carotenoid group and has extremely strong antioxidant properties.Astaxanthin has more and more attention because of its physiological activity.Mastering the growth characteristics of Haematococcus pluvialis and the transformation conditions of astaxanthin can further promote the wide application of astaxanthin.Haematococcus pluvialis is extremely harsh on growth conditions and is susceptible to contamination during the cultivation process,requiring the entire test operation to be carried out under aseptic conditions,sterilization,disinfection and sterilization.The growth conditions of Haematococcus pluvialis and the accumulation conditions of astaxanthin are different,and the whole cultivation process needs to be cultivated in an artificial incubator.The whole cultivation process of Haematococcus pluvialis is mainly divided into two stages: the green stage and the red stage.The green stage is mainly the growth stage of Haematococcus pluvialis.The cultivation and expansion of Haematococcus pluvialis are here The stage is carried out;the red stage is the stage in which Haematococcus pluvialis accumulates astaxanthin,and the green algae cells gradually produce red cells to become red cells under the change of environmental conditions.Explore the effects of temperature,light intensity and p H on the growth of Haematococcus pluvialis.Single factor test results: temperature 24 ?,light intensity 2000 lux,p H 8.0 can increase the cell density of Haematococcus pluvialis.By analyzing the orthogonal test results,the optimal level combination is obtained: temperature 24 ?,light intensity 2000 lux,p H 8.0.The optimal level combination was verified,and the density of Haematococcus pluvialis was 8.5 × 105 / m L,and the obtained value was basically the same as the maximum value of the orthogonal test(there was no significant difference in the data).The effects of light intensity,conversion temperature,light cycle,conversion time and p H on the conversion of Astaxanthin by Haematococcus pluvialis were studied.Through the analysis of the single-factor test results,it can be seen that the conversion conditions of Haematococcus pluvialis astaxanthin are very harsh,and the best single-factor conditions are obtained: the light intensity is 6500 lux,the conversion temperature is 30 ° C,and the light cycle is 12: 12.The conversion time is 10 days and the p H is 9.0.By analyzing the orthogonal test results and the range analysis table,it can be concluded that among the various influencing factors,the effect of light intensity> conversion time> temperature,and the influence of light intensity and conversion time on astaxanthin conversion reached a significant level,but the temperature did not reach Significant level,therefore,the best conditions for astaxanthin conversion are light intensity 6500 lux,conversion time 10 d,conversion temperature 30 ?.The solvent extraction method was used to study the extraction solvent,time,temperature,extraction times,and material-liquid ratio,to further obtain the optimal extraction conditions and improve the extraction efficiency of astaxanthin.The best conditions for astaxanthin extraction.Through the analysis of the single factor test,the mixed solvent of dimethyl sulfoxide and acetone is used as the extraction solvent,and the extraction effect is the best when the volume ratio is 4?1,the temperature is 50 ?,the extraction time is 40 min,and the material-liquid ratio When it is 1?7 and the extraction frequency is 4 times,the extraction effect of astaxanthin is obviously better.In order to further determine the more accurate optimal extraction conditions,the response surface model of the three main conditions that affect the extraction of astaxanthin,temperature,extraction time,and material-to-liquid ratio,was analyzed at a temperature of 45.22 ? and an extraction time of 38.12 min When the material-liquid ratio is 1?6.8,the maximum extraction amount of astaxanthin can be reached.After calculation,the extraction amount under this condition is 36.90 mg / L.The mice were given a subcutaneous injection of 200mg/(kg·bw)of D-galactose solution in the back of the neck once a day.Simultaneously add purified astaxanthin and Haematococcus pluvialis astaxanthin to the mice and feed them for six weeks.After the experiment,the weight of mice,the contents of SOD,GSH,MDA,and CAT in serum and liver,and the m RNA expression levels of IL-1?,IL-6,and TNF-? inflammatory factors in liver and serum were measured to study the astaxanthin Anti-aging effects of aging mice.The results show that astaxanthin can reduce the increase of inflammatory factors caused by D-galactose in the liver of mice,fight the imbalance of oxidative stress,protect the liver of mice,and relieve the aging of mice. |
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