Modelling of light and temperature influences on cyanobacterial growth and biohydrogen production

Abstract

Dynamic simulation is a valuable tool to assist the scale-up and transition of biofuel production from laboratory scale to potential industrial implementation. In the present study two dynamic models are constructed, based on the Aiba equation, the improved Lambert–Beer's law and the Arrhenius equation. The aims are to simulate the effects of incident light intensity, light attenuation and temperature upon the photo-autotrophic growth and the hydrogen production of the nitrogen-fixing cyanobacterium Cyanothece sp. ATCC 51142. The results are based on experimental data derived from an experimental setup using two different geometries of laboratory scale photobioreactors: tubular and flat-plate. All of the model parameters are determined by an advanced parameter estimation methodology and subsequently verified by sensitivity analysis. The optimal temperature and light intensity facilitating biohydrogen production in the absence of light attenuation have been determined computationally to be 34 °C and 247 μmol m− 2 s− 1, respectively, whereas for cyanobacterial biomass production they are 37 °C and 261 μmol m− 2 s− 1, respectively. Biomass concentration higher than 0.8 g L− 1 is also demonstrated to significantly enhance the light attenuation effect, which in turn inducing photolimitation phenomena. At a higher biomass concentration (3.5 g L− 1), cyanobacteria are unable to activate photosynthesis to maintain their lives in a photo-autotrophic growth culture, and biohydrogen production is significantly inhibited due to the severe light attenuation

Dynamic modeling of green algae cultivation in a photobioreactor for sustainable biodiesel production

“…This shows, that the FAME production rate always increases with increasing nitrogen quota, while an optimal value exists for light intensity as intense illumination can damage the essential proteins for algal photosynthesis and carbon fixation. Based on the model, the optimal light intensity is identified to be 96 µmol m −2 s −1 , falling within the range of optimal light intensities reported in other publications (Zhang, Dechatiwongse, et al, ). In addition, attention should be paid to the fact that both the local biomass growth rate and the FAME production rate shown in Figure represent instantaneous values, as the location of individual algal cells change continuously as a result of mixing.…”

“…Recent studies have concluded that light attenuation is one of the primary limiting factors for biomass cultivation and bioproduct production (Béchet et al, ; Zhang, Dechatiwongse, et al, ). Similar results are obtained in the present work.…”

“…Meanwhile, developing robust dynamic optimization algorithms for highly nonlinear biosystems is also regarded an important prerequisite for this work to be accomplished successfully. So far, different models have been developed to simulate the effect of key operating conditions on both microalgae growth and biofuel production (Adesanya et al, 2014;Angun, Demiray, Ozkan, Elibol, & Tekinay, 2012;Zhang, Dechatiwongse, et al, 2015). Specific variables including pH, dissolved oxygen, chlorophyll fluorescence (Y(II)), or light irradiation have been used to monitor the process performance and design control schemes (Bernard et al, 2016;Keymer et al, 2013;Yoo et al, 2014;Yoo, La, Kim, & Oh, 2015).…”

Identification and phenotypic plasticity of Pseudanabaena catenata from the Svalbard archipelago

“…Our findings agree with those of Zhang et al (2015), who suggested that light exposure increase can cause considerable damage to the photosynthetic apparatus of cyanobacteria and subsequently lead to a sharp decrease in growth rate. Moreover, in the absence of light, the ability to grow will be reduced, and the cells will eventually die (Dehning and Tilzer 1989).…”

Extracellular Polymeric Substance (EPS) Production by <i>Nostoc minutum</i> under Different Laboratory Conditions

“…However, for still cultures the light intensity showed a slight incidence. Different authors reported the importance to consider this parameter because it is often found as a limiting factor in culture systems [19] [20]. The efficient air-lift stirring of the glass columns plays a crucial rol for reducing shading between cells, thus allowing to obtain higher values of biomass than in still cultures.…”