【作者】 张怀瑾；

【导师】 蔡中华；

【作者基本信息】 清华大学 ， 海洋生物学， 2016， 硕士

【摘要】 虾青素是自然界广泛存在的一种橘红色类胡萝卜素,广泛应用于食品、药品以及化妆品等行业,具有极大的应用价值。在虾青素的制备中,雨生红球藻是生产虾青素的最有效来源,目前提高虾青素产量的方式主要有两种:提高藻细胞的生物量和产物合成效率的提高。针对生物量的优化,以往的工作已针对雨生红球藻的培养条件进行了优化,并取得了一定的效果。但从性价比考虑,依然存在改善的空间。为此,本实验尝试用城市生活污水进行雨生红球藻的培养。结果表明生活污水能促进雨生红球藻的生长,与现有的BG11培养基相比,其平台期生物量是对照组的2倍;同时虾青素的合成时期显著提前(P<0.05),且体内重金属含量未明显富集,处在安全浓度范围。此外,养藻后的城市生活污水中氮磷含量显著降低(P<0.05),高氮磷富余的情形得到有效改善。同时,我们对一株从雨生红球藻藻际微生物分离得到的戈登氏菌种(Gordonia terrae)进行了研究,确认在该菌种的代谢过程中会合成类胡萝卜素。通过研究不同培养条件,我们确定了能获得最大主要产物含量的条件。同时,该菌种的提取物具有与雨生红球藻提取物相当的抗氧化性,并且在高温及低浓度氧化剂存在下也具有较强的稳定性,具有极大的应用价值。值得注意的是,该菌种分离自雨生红球藻藻际微生物,其可能参与雨生红球藻的虾青素合成过程,具有极高的研究前景。更多还原

【Abstract】 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.更多还原