In order to lower the cost of lipid production of microalgae and reduce greenhouse gas emissions, microalgae Chlorococcum alkaliphilus MC-1 with the characteristics of rapid pH drift and high pH adaptability, was cultivated with bubbling of flue gas. The experiment was first performed in the photobioreactor (15 L) in three groups (control group, CO2 group and flue gas group), then, in the open raceway pond (24 m2). The adaptability of microalgae MC-1 to the cultivation with flue gas was studied. The results showed that the maximum biomass concentration, growth rate, total lipid content and CO2 fixation rate were (1.02+/-0.07) g/L, (0.12+/-0.02) g/(L.d), (37.84+/-0.58)% and (0.20+/-0.02) g/(L.d) in the photobioreactor treated with flue gas, 36%, 33.33%, 15.34% and 33.33% higher than those of the CO2 group, respectively. In the open raceway pond with aeration of flue gas, the maximum biomass concentration, growth rate, total lipid content and CO2 fixation rate were 147.40 g/m2, 14.73 g/(m2.d), 35.72% and 24.01 g/(m2.d), respectively, which were similar to the cultivation with pure CO2. The toxic heavy metal contents (Pb, As, Cd and Cr) in the biomass of MC-1 treated with flue gas were all below the legal limits. Additionally, the absorptive effect of CO2, NO and SO2 were determined. In the photobioreactor and open raceway pond, the average absorption ratios of these gases were all higher than previous studies. Therefore, our study showed that MC-1 can adapt to the cultivation with flue gas, and it is feasible to enlarge the outdoor cultivation of MC-1 for lipid production coupling with emissions reduction of flue gas.
Adaptation, Physiological ; physiology ; Carbon Dioxide ; chemistry ; Chlorophyta ; classification ; growth & development ; physiology ; Culture Media ; metabolism ; Culture Techniques ; methods ; Gases ; chemistry ; Microalgae ; classification ; growth & development ; physiology ; Nitric Oxide ; chemistry ; Sulfur Dioxide ; chemistry

【Objective】 To construct an in-vitro model of erythrocyte antibody-mediated complement activation, and establish quantitative detection methods based on flow cytometry and spectrophotometry, so as to explore the correlation of anti-body titers and complement activation speed, and provide a methodological basis for studying the adverse transfusion reactions of anti-body mediated complement hemolysis. 【Methods】 Mouse monoclonal antibody that recognized human C3b and fluorescent secondary antibody were used to label C3b fragments on erythrocytes, and the deposition of C3b fragments after complement activation was detected by flow cytometry. The absorbance at 540 nm of the supernatant in the complement activation reaction system was measured by spectrophotometry as the amount of hemoglobin released was related to the absorbance. 【Results】 The complement activation system was constructed according to the ratio of 3% red blood cell suspension (mixed for 6 people) 1∶anti-Tj^a 1∶complement 2. The repeatability was good (P value>0.05) as different red blood cell mixtures had been used to repeat the detection reaction system. When using 32×, 64× and 128× dilutions of anti-Tj^a mediated complement activation, the deposition of C3b fragments has been detected by flow cytometry at 30 s, 1 min and 2 min, respectively, and MFI peaked at 5 min, 10 min and 30 min, respectively. No obvious hemolysis has been observed within 1.5 h. 【Conclusion】 In vitro model of anti-Tj^a-mediated complement activation demonstrates the speed of complement activation is related to the concentration of antibody. At a certain antibody concentration, the speed of complement activation has been slowed down, and no obvious hemolysis observed.