Optimization Of Haematococcus Pluvialis Cultivation And The Bacteria In Its Phycophere Environment

Astaxanthin,a red-orange carotenoid pigment,is a powerful biological antioxidant that occurs naturally in a wide variety of living organisms.As a valuable natural product,astaxanthin was widely used in food and cosmetics industry,and considerable potential applications in human health and clinical medicine.Among the acquire process of astaxanthin,Haematococcus pluvialis is the most effective biological source.There are two ways to increase the production of astaxanthin: increasing the biomass and improving the synthesis efficiency.In order to pursue the higher biomass,previously research works were focused on culture conditions' optimization of H.pluvialis.In spite of many positive results was obtained,there is still a long-way to achieve the highest cost performance ratio.Thus,we try to use the municipal wastewater as medium to culture the H.pluvialis.The results shows that swage can improve the growth of H.pluvialis greatly,and the biomass is over 2-fold than the control medium(BG11medium)during the plateau period.After detect the level of heavy metal content in the H.pluvialis cell,there was no significant heavy metal enrichment in the algal body.The hazardous metal concentrations in the safe range.In addition,the new develop method can accelerate the products synthetise,and made the synthetic period of astaxanthin advanced significantly(P<0.05).Besides,it is worth noting that the content of nitrogen and phosphorus in the sewage reduced significantly with the growth of algae(P<0.05),eutrophic wastewater has been efficiently improved.Tanken together,Our experiment demonstrate the feasibility to culture H.pluvialis by sewage.It can bring us double effects: accumulation algal biomass,and helpful to purify water quality.This work can help us to gain excellent economic and ecological benefits in algae culturing industry.At the same time,we studied a novel carotenoids-producing bacteria isolated in H.pluvialis phycophere environment.Studying different culture conditions,we determined the optimum condition that can get the maximum content of the main product.Meanwhile,the antioxidant activity of bacteric extractive is the same as H.pluvialis extractive.And the bacteric extractive has strong stability at high temperatures and low concentrations of H2O2,implying it has great application value.Interestingly,the bacteria was isolated from H.pluvialis phycophere environment,whichmay be involved in astaxanthin synthesis pathway of H.pluvialis,with a high research prospects.