Industrial oil-producing microalgae can synthesize large quantities of oil sesame under nitrogen-deficient stress, and this stress response is one of the scientific bases of microalgae energy.
recently, the single-cell center of Qingdao Institute of Bioenergy and Process of the Chinese Academy of Sciences constructed a dynamic model of proteomics under nitrogen deficiency pressure for micro-algae, revealing the three physiological stages of the stress process and providing a new perspective for oil metabolism engineering.
published in Biotechnology for Biofuels.
the process of oil accumulation of industrial oil-producing microalgae under nitrogen pressure has been closely watched by academic circles and industry.
the tatterical center of Qingdao Energy Institute constructed its mechanism model based on transcription groups and metabolite groups (Plant Cell, 2014, DOI:10.1105/tpc.113.111418), however, there were important differences in the experimental data at the transcriptomic level and the metabolomics level, which could not be fully explained by the delay between gene expression and metabolic regulation.
this is due to the fact that the process from transcription to metabolites is still regulated by the protein level.
in response to this problem, the researchers published the micro-algae nitrogen deficiency time series of proteomic data, combined with the corresponding transcription group and metabolic group data, the application of the latest statistical analysis methods, more comprehensively revealed the cell in nitrogen-deficient stress synthesis of triglycerides process characteristics.
researchers found that the process can be divided into three phases.
the initial stage of nitrogen deficiency: at this time the cells feel the lack of nitrogen in the outside environment, but because there is a certain amount of nitrogen reserves in the cell, the change of its metabolic process is not obvious.
nitrogen deficiency in the middle of the period: this stage of cell preservation of nitrogen has been roughly consumed, the need to protein degradation and other ways to recover nitrogen in amino acids, in order to maintain the operation of the cell's key metabolic processes, while photosynthesis and lipid metabolism and other processes have been affected to varying degrees.
later nitrogen deficiency: cells further improve the rate of protein degradation, while the rate of triamcinolone circulation and oil synthesis increased significantly, although the rate of photosynthesis decreased but still worked.
this revised model more accurately depicts the process of nitrogen deficiency oil production, and further proves that triglycerides play a leading role in the accumulation of fat from the beginning, while membrane fat recovery represents only a small part of lipid accumulation.
this model provides a series of new strategies and objectives for the directed regulation of microalgae metabolism control network to improve the yield of fat.
the research was completed by the Department of Plant Biochemistry of Ruhr University in Germany and the single cell center of Qingdao Energy Institute, and was supported by the Carbon Gas Biotransformation Project of the Chinese Academy of Sciences, the China-Germany Center of the Fund Committee, etc.
Source: Qingdao Bioenergy and Process Research Institute.