Patiño Rodrigo, Janssen Marcel, von Stockar Urs
Departamento de Física Aplicada, CINVESTAV-Unidad Mérida, Apartado Postal 73, Cordemex, 97310 Mérida, Yucatán, Mexico.
Biotechnol Bioeng. 2007 Mar 1;96(4):757-67. doi: 10.1002/bit.21182.
Calorimetry and other on-line techniques are used for the first time as complement to the traditional off-line methods in order to follow the growth of the green Chlorella vulgaris microalgae. A 2-L photo-bio-reactor was adapted from a commercial calorimeter used previously to study heterotrophic microbial growth. An external source of light was added to favor the photosynthesis of the autotrophic cells. Heterotrophic growth was also tested with external glucose in the broth. A third mode, mixotrophic, allowed faster autotrophic plus heterotrophic growth. Calorimetric measurements were performed considering the corresponding calibrations in order to consider only the energy involved during the microalgal growth. The three different modes of Chlorella cultures were energetically characterized. Besides calorimetry, the weight of diluted nitric acid added to maintain the pH of the culture was correlated with the cellular growth and the nitrogen composition of the algae. Additionally, the on-line infrared spectroscopy proved to be an efficient technique to follow the composition of the broth in glucose, nitrates, and phosphates. These results were compared and complemented with some classic off-line techniques used to track this kind of cultures.
首次使用量热法和其他在线技术作为传统离线方法的补充，以跟踪普通小球藻绿藻的生长。一个2升的光生物反应器是由先前用于研究异养微生物生长的商用热量计改装而成。添加了外部光源以促进自养细胞的光合作用。还在肉汤中加入外部葡萄糖测试了异养生长。第三种模式，兼养模式，允许更快的自养加异养生长。进行量热测量时考虑了相应的校准，以便仅考虑微藻生长过程中涉及的能量。对小球藻培养的三种不同模式进行了能量表征。除量热法外，为维持培养液pH值而添加的稀硝酸的重量与细胞生长及藻类的氮组成相关。此外，在线红外光谱法被证明是跟踪肉汤中葡萄糖、硝酸盐和磷酸盐成分的有效技术。将这些结果与用于跟踪此类培养物的一些经典离线技术进行了比较和补充。
