Ricerc@Sapienza

Much of our current knowledge of microbial growth is obtained from studies at a population level. Driven by the realization that processes that operate within a population might influence a population's behavior, we sought to better understand Tetradesmus obliquus (formerly Scenedesmus obliquus) physiology at the cellular level. In this work, an accurate pretreatment method to quantitatively obtain single cells of T. obliquus, a coenobia-forming alga, is described.

A fed-batch strategy is proposed to produce microalgae biomass under non-axenic heterotrophic conditions. The strategy induces the alternation of N-deplete (Glucose-replete) and N-replete (Glucose-deplete) cultivation phases by the periodic and uncoupled supply of glucose and NO3− to the culture. Cultivation of the microalga T. obliquus with this strategy reduced the ratio of the bacteria to microalgae cell concentration from 1.6, attained by conventional photoautotrophic cultivation, to 0.03.