不同培养条件对嗜热蓝细菌生长及活性物质的影响研究

Effects of different culture conditions on the growth and active substances of Thermophilic cyanobacteria

为了探究嗜热蓝细菌的生长特性,文章设置了不同的温度和NaHCO3浓度,研究不同条件对分离所得的两株嗜热蓝细菌Thermosynechococcus elongatus PKUAC-SCT E111和Thermosynechococcus elongatus PKUAC-SCT E732的生长以及活性物质积累的影响,从而预估其固定烟道气中的CO2的潜力。研究结果表明:在一定温度范围内,嗜热蓝细菌的生长速率随着温度的升高而加快;二者均可在高温环境下生长,最佳生长温度均为50℃,其中,Thermosynechococcus elongatus PKUAC-SCT E732可在温度为60℃的条件下缓慢生长;适宜的NaHCO3浓度会促进两株蓝细菌的生长,当NaHCO3的浓度为0.1 mol/L时,两株蓝细菌的生长情况最佳,当NaHCO3的浓度为0.3,0.5 mol/L时,两株蓝细菌能够正常生长,当NaHCO3的浓度达到1 mol/L时,两株蓝细菌均无法存活;提升温度和NaHCO3浓度,能够促进蓝细菌内活性物质的积累,从而增加藻胆蛋白的合成量,改变脂肪酸的组成。

Thermophilic cyanobacteria have showed great potential in fixing industrial flue gas.Hence, we analyzed the effects of temperatures and different NaHCO3 concentrations on cell growth and accumulation of active substancesof two thermophilic cyanobacteria Thermosynechococcus elongatus PKUAC-SCT E111 and Thermosynechococcus elongatus PKUAC-SCT E732. The results showed that between 45 to 60 ℃, the optimal growth temperature of both cyanobacteria are 50 ℃ whilst only Thermosynechococcus elongatus PKUAC-SCT E732 can grow slowly at a higher temperature(60℃). Increasing the concentration of dissolved inorganic carbon with sodium bicarbonate promoted the growth of two cyanobacteria. Two cyanobacteria exhibited the fastest growth rate with 0.1 mol/L NaHCO3 and grow well at 0.3 mol/L and 0.5 mol/L NaHCO3. The 1 mol/L NaHCO3 had deleterious effect for both strains. Results indicated that the two strains could be utilized for CO2 sequestration from flue gasses. Increasing the temperature and concentration of dissolved inorganic carbon to optimal range had positive effect on the biosynthesis of phycobiliproteins and fatty acids, which are valuable products of cyanobacteria.