Effects of Glucose and Xylose on the Production of Astaxanthin by Chlorella zofingiensis in the Dark

目的:以小球藻Chlorella zofingiensis为研究对象,以葡萄糖和木糖为混合碳源,优化混合碳源浓度提高异养培养虾青素产量。方法:利用JMP软件中完全析因设计法考查葡萄糖和木糖浓度对虾青素产量的影响,并采用SAS软件对实验数据进行回归分析。结果:优化条件下葡萄糖和木糖浓度分别为26.86 g/L和16.92 g/L。结论:优化后的虾青素产量达到8.65 mg/L,比初始条件产量7.39 mg/L提高了17%。Objective： Optimization of the concentration of glucose and xylose was carried out to increase astaxanthin yield by ChloreUa zof- ingiensis heterotrophically. Method：Full Factorial Design by software JMP was used to investigate the effects of glucose and xylose on the production of astaxanthin,and the experimental data was analyzed using regression analysis method by software SAS. Result：The optimal concentrations of glucose and xylose were 26. 86 g/L and 16. 92 g/L Conclusion： Astaxanthin yield of C. zofingiensis could reach 8.65 mg/L under optimum concentration,which was 17% higher than that achieved under original concentration （7. 39 mg/L）

主要资源国家政治生态情况及其对铝土矿政策的影响

Vesuvius, dominating the densely-populated Neapolitan area, is one of the most dangerous volcanoes in the World. Its destructive power derives from energetic subplinian and plinian eruptions, such as the one which occurred in 79 A.D. Generally such large-scale events follow a long period of quiescence; a behaviour interpreted as the gradual build-up of magma volumes between periods of major activity. After the 1631 subplinian eruption until the last 1944 A.D. eruption, it experienced an almost continuous and less energetic explosive/effusive activity. The erupted magmas are characterized by undersaturated potassic to ultrapotassic nature, and compositional and Sr-isotopic variability. Furthermore geobarometric studies indicate two different crystallization depths located at 4 and >11 km, respectively. According to most of the recent literature, the eruptions were triggered by the injection in a shallower magma chamber, of isotopically distinct magma batches derived from heterogeneous mantle source(s) and/or contamination processes occurred within the deep reservoir. In our review of petrochemical data, we consider the period between the 3550 years BP plinian eruption and the 472 A.D. sub-plinian eruption, which includes 79 A.D. event, and the most recent period of activity which started in 1631 A.D. and lasted up to the 1944 A.D. eruption, characterized by a near continuous effusive/explosive activity. For both periods we identify a correlation between Sr-isotopical features of magmas and their crystallization depth. In particular, we show that pyroxenes have Sr-isotopic ratios lower than 0.7074 and an equilibrium crystallization depth of 22-11 km. Moreover feldspars have higher 87Sr/86Sr values (0.7075-7) and an equilibrium crystallization depth of about 4 km. Therefore the most radiogenic magmas did not derive from a deeper reservoir but their higher Sr-isotopic ratios have been acquired at a shallower depth likely by crustal contamination during magma evolution. In contrast, the lower Sr-isotope compositions characterise the less contaminated magmas coming from deeper crustal levels. On the basis of this evidence, the temporal Sr-isotopical variation of magma which erupted in the 1631-1944 A.D. period probably derives from the progressive withdrawal of the shallow magma chamber, which was completely empty before the 1805-1944 A.D. period of volcanism. Therefore the effusive and explosive events of the most recent 1805-1944 A.D. period were fed directly by the deep reservoir located at a depth exceding 11 km