负压式光生物反应器对微藻的培养效果

采用一种新型负压式光生物反应器对常用饵料微藻威氏海链藻(Thalassiosira weissflogii)的培养效果进行研究,分析培养过程中藻密度、异养菌与弧菌(Vibrios)数量及氨氮与亚硝酸氮质量浓度变化及相互关系。结果表明:在负压光生物反应器培养下威氏海链藻的生长速度快,培养第4天达到平台期,藻密度最大值可达到1.5×10~6个/mL,最大比生长率可达1.37;弧菌与异养菌数量两者变化趋势相同,分别为(0.19～2.70)×10~4 cfu/mL和(0.071～0.93)×10~6 cfu/mL,藻与细菌表现出相互竞争抑制的效果,在指数增长期藻对细菌抑制较强,特别是对弧菌的抑制,在平台期与衰败期藻对弧菌与异养菌的抑制作用逐渐减弱。藻液中氨氮与亚硝酸氮质量浓度随藻密度增加而上升,最高值分别达到0.24 mg/L和0.37 mg/L,指数增长期藻密度与氨氮和亚硝酸氮质量浓度呈显著正相关(P0.05)。因此,采用负压式光生物反应器培养威氏海链藻,可以大大缩短培养周期,抑制细菌生长,提高培养效率和藻液质量,但需要在投喂幼体前对藻液进行充分曝气来降低氨氮与亚硝酸氮质量浓度。该反应器是一种适合饵料微藻培养的系统。研究结果为负压光生物反应器作为微藻生物饵料培养系统的应用提供了参考依据。

Culture effect of negative pressure photobioreactor on microalgae

A new type of negative pressure photobioreactor was used to explore culture effect of feeding microalgae-Thalassiosira weissflogii. The change of algae density, the quantity of heterotrophic bacteria and Vibrios, the mass concentration of ammonia nitrogen and nitrite nitrogen, and their relationship were investigated. Thalassiosira weissflogii grew fast and reached plateau stage on the 4th day of culture, the highest value of algal density was 1.5×10⁶ cells/mL,and the specific growth rate was 1.37. Quantities of vibrios and heterotrophic bacteria ranged from (0.19-2.70)×10⁴ cfu/mL and (0.071-0.93)×10⁶ cfu/mL, respectively. Compared to the plateau and decay periods, algae had strong inhibition on bacteria in the exponential growth stage, especially vibrios. The mass concentration of ammonia nitrogen and nitrite nitrogen in algae solution were accompanied by increased algae density, and the highest value was 0.24 mg/L and 0.37 mg/L, respectively. The algae density was positively correlated with the mass concentration of ammonia nitrogen and nitrite during the exponential growth period (P<0.05). The negative pressure photobioreactor could shorten the cultivation period, inhibit the growth of bacteria,improve the cultivation efficiency and the quality of algae solution. It is a system suitable for feeding microalgae culture. But it''s worth noting that the algae solution should be fully aerated to reduce the mass concentration of ammonia nitrogen and nitrite nitrogen before feeding the larvae. This study provides reference for the application of negative pressure light bioreactor as feeding microalgae culture system.