ABSTRACT
Light quality can regulate both psbA genes and vector promoter psbA of the engineered Synechococcus. Through light regulation, we tried to improve yield of the recombinant protein for vp28 gene-expressed Synechococcus sp. PCC7002. To drive photon-capturing efficiently, three limiting factors (irradiance, temperature and pH) were optimized by measuring net photosynthesis. High cell density cultures were performed with variant ratios of white, red and blue light in a 5-L photo-bioreactor. Yields of biomass, expressions of vp28 and transcription levels of psbA were compared. High ratio blue light-induced vp28 transcription had tripled and the relative accumulation of VP28 protein was doubled. The relative expressions of psbAII and psbAIII had positive correlations with higher ratio of blue light, not the red light. With high ratio red light inducing, dry biomass reached 1.5 g/L in three days. Therefore, we speculated that red light accelerated biomass accumulation of the transgenic strain and blue light promoted transcription for PpsbA and psbA. These results provided useful information for mass production of cyanobacteria and its secondary metabolites.
Subject(s)
Gene Expression Regulation, Bacterial , Light , Photosystem II Protein Complex , Genetics , Promoter Regions, Genetic , Synechococcus , Genetics , Radiation EffectsABSTRACT
Over the past years efforts have been made by the government to improve the management of clinical laboratories.The government activities such as networking of quality assurance, development and implementation of clinical laboratory standards, and establishment of external quality control mechanisms have facilitated the improvement of clinical laboratory quality.Further definition and integration of clinical laboratory services, introduction of clinical laboratory pathologists and consultation and establishment of a permission mechanism are needed for improving the effectiveness of clinical laboratory services.Government regulations will continue to play an essential role in the clinical improvement process.