Torres, María J.
[Verfasser:in];
Gonzalez-Ballester, David
[Verfasser:in];
Gómez-Osuna, Aitor
[Verfasser:in];
Galván, Aurora
[Verfasser:in];
Fernandez, Emilio
[Verfasser:in];
Dubini, Alexandra
[Verfasser:in]
Chlamydomonas-Methylobacterium Oryzae Cooperation Leads to Increased Biomass, Nitrogen Removal, and Hydrogen Production
Beschreibung:
In the context of algal bioremediation of wastewater, the bacteria Methylobacterium oryzae and the microalga Chlamydomonas reinhardtii established a collaborative relationship when incubated in media containing ethanol and methanol. Growth (1.22 g·L-1·d-1 dry weight biomass) and inorganic nitrogen removal were greatly improved (>99%). Hydrogen production was also achieved (33.5 mL·L-1). The key metabolic aspect of this relationship relied in the bacterial oxidation of ethanol to acetic acid, which was assimilated by the alga. Acetic acid accumulation (up to 18.8 mM) had an inhibitory effect over the bacterial growth. Moreover, in the absence of methanol, ethanol was not efficiently utilized by the bacteria and its partial oxidation had a toxic effect on both the alga and the bacterium. However, in cocultures grown in the presence of both alcohols these inhibitory effects were overcomed and both microorganisms mutually benefited. Potential biotechnological applications regarding wastewater treatment, biomass generation, and hydrogen production are discussed