Advances in the research and applications of orange fluorescent protein / 生物工程学报

Fluorescent proteins can be used as probes to investigate intercellular molecular interactions and trace the pathway of specific metabolites, thus providing a detailed and accurate description of various metabolic processes and cellular pathways in living cells. Nowadays, the existing fluorescent proteins cover almost all spectral bands from ultraviolet to far-red. These fluorescent proteins have been applied in many fields of bioscience with the help of high-resolution microscopy, making great contributions to the development of biology. It is generally agreed that orange fluorescent proteins refer to the fluorescent proteins at the spectral range of 540-570 nm. In recent years, researches on orange fluorescent proteins have made great progress, and they have been widely applied in the field of biology and medicine as reporter protein and fluorescence resonance energy transfer as fluorescent receptor. This paper reviews the studies in the field of orange fluorescent proteins over the last 15 years, with the special focus on the development and application of orange fluorescent proteins to provide the basis for the future studies.

Pathogenicity of white-spot syndrome virus in Macrobrachium nipponensis via different infection routes / 生物工程学报

Macrobrachium nipponensis is delicious and has high economic value, but its susceptibility to white-spot syndrome virus (WSSV) is unknown. Susceptibility, morbidity, and multiplication of WSSV in M. nipponense were studied by epidemiological survey, infection experiment and qPCR. M. nipponense was the natural host of WSSV, and the natural carrying rate was about 8.33%. M. nipponense could be infected with WSSV via oral administration, muscle injection and immersion, and the cumulative infection rate of 10 d exposure was 100%, and the cumulative mortality rates were 100%, 75% and 0%, respectively. The infection of WSSV is fast by muscle injection. The virus content after 5 day's injection is 1 000 times higher than that of the first day of infection, and the mortality rate reached 100% after 8 days. The median lethal dose (LD₅₀) measured as the mortality of infected M. nipponense via injection indicated the LD₅₀ in the concentration of WSSV of 2.71×10⁵ virions/μL. In shrimp farming, M. nipponense can be infected by ingesting WSSV infected shrimp or dead shrimp, and also by soaking in WSSV-containing water and thus become a vector, consequently affecting the spread and pathogenicity of WSSV.

Effects of light quality on cell growth and psbA promoter of engineered Synechococcus sp. PCC7002 / 生物工程学报

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.

Exploitation and utilization of rich lipids-microalgae, as new lipids feedstock for biodiesel production--a review / 生物工程学报

As a renewable energy sources to replace conventional fossil fuels, biodiesel fuels have been becoming increasingly requirements to global fuels market. Biodiesel derived from oil crops cannot realistically satisfy even more fraction of the raw material existing costs and soil competitive demand for its growth. Microalgae appear to be the advantage of costs that is capable of higher photosynthetic efficiency, larger biomass, faster growth compared to those of oil crops. Lipid content of many microalgae is usually 80% of its dry weight. Genetic microalgae with high-oil productivity by genetic manipulations are capable of making microalgal biodiesel economically competitive with petrodiesel through large-scale production of genetic microalgal biomass. As demonstrated here, the use of biodiesel fuels in home and abroad are currently introduced, and the cost advantage of microalgae as the raw material is analyzed; And moreover, the progress of microalgal genetic engineering in regulation of lipid metabolism and the problems in the construct of genetic microalgae strains as well as approaches for making microalgal biodiesel appear to be an important source of renewable fuel that has the potential to completely displace fossil diesel are discussed in this review.