Font Size: a A A

Study On The Metabolic Network Of Synechococcus By Multi-objective Optimization Method

Posted on:2021-05-02Degree:MasterType:Thesis
Country:ChinaCandidate:Y F MengFull Text:PDF
GTID:2370330629484242Subject:Computer Science and Technology
Abstract/Summary:PDF Full Text Request
Biomass energy is a kind of renewable and clean energy in nature,which is characterized by high accessibility,little pollution and large total resources.With the increasing shortage of petroleum energy in the world and the drastic change of global climate,it is of great significance for the establishment and development of energy system to improve the production rate of biomass energy.As the only renewable energy that can be stored and transported,photosynthetic synechococcus can convert the light energy into the biomass energy stored in the organism through photosynthesis.Synechococcus has become a hot research object in recent years because of its wide distribution,easy survival,strong nitrogen fixation ability and the main participants of global carbon cycle.From the perspective of cell metabolism,the complex functions and functions in organism can be studied by connecting the components and structural units of organism.By studying the metabolic network of organisms,we can understand the metabolic process and network characteristics of organisms,it lays a solid foundation for better understanding of biological evolution,promoting the further development of bioengineering and producing excellent target metabolites.In this paper,the iJB785 model of synechococcus is taken as the experimental object to study the characteristics and internal relations of metabolic network.To establish a constraint-based metabolic network model and use the flux balance analysis(FBA)to knock out different reactions,and to observe and analyze the effects of these knock-out reactions on other reactions and important metabolic pathways in the metabolic network,the effects of these reactions on the target function(e.g.Biomass)of the organism are observed.According to the distribution of the effects,the reactions in the metabolic network are classified functionally.Flux variability analysis(FVA)was used to obtain the flux variability of all the reactions in the wild-type metabolic network,knocking out the different enzymes in the metabolic network,the effects on the minimum flux(minFlux)and maximum flux(maxFlux)of other reactions in the metabolic network were observed.In the metabolic network system of organisms,there are often many equivalent optimal ways to achieve the same target value(such as biomass),through uniform random sampling analysis can obtain multiple equivalent replacement optimal solution range,the best value and the range of the best value of each reaction are determined,and the scatter plot of the relationship among the reactions in the metabolic network is drawn by using the scatter plot matrix.The traditional gene/reaction knock-out simulation experiment is a kind of method that the experimental results are all-in-one and not quite strong,this method is easy to make the simulation result produce distortion.In this paper,the multi-objective optimization method is introduced into the simulation analysis of the effects of different flow rates for the first time to predict the possible performance types of organisms.The quantitative study on the relationship between the responses in metabolic networks makes the simulation results more practical and has important reference significance for understanding the relationship between genotype and phenotype of organisms.
Keywords/Search Tags:Synechococcus, Metabolic network, Flux Balance Analysis, Flux Variability Analysis, Uniform Random Sampling, Multi-objective Optimization
PDF Full Text Request
Related items