Study of morphological and phisiological characteristics of Chlorella protothecoides oriented to lipid production for biofuel

Abstract

The microalgaes have an enormous potential as energetic source, though the massive production of biodiesel has really high costs, which make the system not sustentable. There exist low costs alternatives that involve auto- and heterotrophic crops to improve the performance; however, not all microorganisms have the same capacity that Chlorella protothecoides has to grow just with a nitrogen or carbon source. To study its morphology and physiology, C. protothecoides was cropped autotrophically and heterotrophically in glass bubble column bioreactors with constant airflow. The control of variables was done through multi-parametric flow cytometry using Propidium Iodide and Nile Red. The results showed that the microalgaes in their growing phases have different sizes, cellular content and lipid concentration, with a maximum of 24.5% w/w of lipid acids and 4.5 g/l of biomass. There was also observed that in the heterotrophic growth, the cells lose their chloroplasts and their photosynthetic capacity, increasing the efficiency in the production of lipid acids.