Ammonia inhibition on Arthrospira platensis in relation to the initial biomass density and pH

• Published in: Bioresource technology Vol. 166; pp. 259 - 265
• Main Authors: Markou, Giorgos, Vandamme, Dries, Muylaert, Koenraad
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2014; Elsevier
• Subjects: Ammonia; Ammonia - toxicity; Ammonia inhibition; Ammonia losses; Biofuels; Biological and medical sciences; Biomass; Bioreactors; Cell Culture Techniques; Concentration (composition); Cultivation; Culture; Density; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Inhibition; Microalgae; Nutrients; Spectrophotometry; Spirulina - drug effects; Spirulina - growth & development; Nutrients; Microalgae; Biomass; Ammonia inhibition; Ammonia losses; Density; Ammonia; Cyanobacteria; Spirulina platensis; pH; Bacteria; Nutrient; Alga; Inhibition; Microorganism
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2014.05.040

•Arthrospira growth with ammonia as nitrogen source was performed.•The effect of NH3 concentration, initial biomass density and initial pH was studied.•NH3 inhibition is neither a biomass-independent nor biomass-dependent phenomenon.•In low NH3 concentration growth rates decreased due to nitrogen limitation.•NH3 stripping and losses were high as 80%. In this study the combined effect of total ammoniacal nitrogen (TAN) concentration, initial biomass density and initial pH of the cultivation medium on growth of Arthrospira platensis was studied. The results indicate that TAN inhibition in relation to the initial biomass in unregulated pH cultures is neither a clearly biomass-independent nor biomass-dependent phenomenon. However, low biomass densities are more susceptible to ammonia inhibition than higher biomass densities. Higher biomass densities seems to mitigate ammonia inhibition through rapider assimilation of TAN. In all cases studied the growth rates were lower compared to the cultures with nitrate as nitrogen source. It was observed that at low TAN concentration, although no ammonia inhibition occured the growth rates were decreased due to nitrogen limitation. Low TAN concentration triggered the accumulation of carbohydrates affecting thus significantly the biomass composition. Ammonia losses from the cultivation system were also determined. Ammonia losses ranged between 17% and 80%.