Analysis Of The Effect Of Light On The Growth And Polysaccharide Content Of Euglena Gracilis Based On Metabolomics And Proteomics

In this study,Euglena gracilis was used as the experimental object.By optimizing the light culture conditions(light intensity,photoperiod and light wavelength),the effect of light on the growth and development of Euglena gracilis was studied through the results of single factor experiments,and orthogonal experiments were determined using polysaccharide content as an indicator.Factor levels were designed using orthogonal experiments to determine suitable complex lighting conditions for accumulation of euglena polysaccharides,and further metabolomics and proteomics were used to analyze changes in metabolites and protein expressions after light optimization,in order to study the growth of euglena The molecular mechanism of material changes and targeted culture of target products provide basic data.1.The effects of light intensity,photoperiod and light wavelength on cell density,photosynthetic pigments,and photosynthetic pigment content of Euglena gracilis were studied by single factor experiments,in order to obtain the optimal illumination conditions suitable for growth and photosynthetic pigment of Euglena gracilis.Studies have shown that: light has significant effects on the growth,photosynthetic pigments,and polysaccharide content of Euglena gracilis(P <0.05).When the light intensity is 3000 lx,it is beneficial to the growth of Euglena gracilis and the accumulation of photosynthetic pigments;the dark period is 14L: 10 D,it is beneficial for the growth of photosynthetic euglena and accumulation of photosynthetic pigments;blue light facilitates the growth of eutropha and photosynthetic pigment accumulation.2.Based on the results of the single-factor test and the orthogonal test design,using the content of slender Euglena polysaccharides as an indicator,the optimal lighting conditions for the accumulation of polysaccharides were studied.The results showed that at a light intensity of 4500 lx and photoperiod of 14L: 10 D,under the condition of blue light,the polysaccharide content reached the highest,which was41.5mg / L.The factors affecting the polysaccharide content are: photoperiod,light intensity,light wavelength.3.Analysis of Metabolic Differences and Metabolic Pathways of Euglena gracilis before and after Light Optimization Using Metabolomics,the results showed that: the light conditions significantly affected the production of differential metabolites,and 116 were detected in the light-treated group and the control group under positive and negative ions.There were differences between the two treatment groups on the types and expressions of metabolites.The types of metabolites were mainly concentrated on amino acids,sugar alcohols and organic acids.4.Proteomics measurements of Euglena gracilis before and after light optimization were performed using protein technology.A total of 40 differential proteins were identified,of which 21 were up-regulated and 19 were down-regulated.Hierarchical clustering,GO annotation and kegg pathway analysis of differential proteins,the results show that light has a significant effect on the carbohydrate and energy metabolism proteins of Euglena gracilis,especially affecting glycolysis /gluconeogenesis,TCA cycle,photosynthetic carbon Content and expression of proteins associated with fixed metabolic pathways.5.The combined analysis of metabolomics and proteomics showed that the light treatment had significant effects on TCA cycle,photosynthetic organisms carbon fixation,glucose metabolism and other metabolic pathways.