Microalgae culture

Figure 17. Microalgae culture in open system (raceway) and close photobioreactor (Almeria University and Palmerillas Research Center).

MAXIMIZING PHOTOSYNTHETIC EFFICIENCIES AND HYDROGEN PRODUCTION IN MICROALGA CULTURES... 

Maximizing Photosynthetic Efficiencies and Hydrogen Production in Microalga Cultures... 

Despite the fact that productivity of chemostat operation is similar to turbidostat operation the turbidostat is preferred especially at locations with more day-to-day variation in irradiance. Under chemostat operation biomass concentration will slowly decrease on consecutive days with cloud cover. If followed by a clear-sky day, the culture is vulnerable to photoinhibition because of its low biomass concentration. Turbidostat operation allows for a direct control of biomass concentration. Washout of a microalgae culture in a turbidostat is by definition not possible. In a chemostat this could occur in situations the dilution rate is not adjusted in time. Turbidostat operation is thus more robust and allows for rehable automation of outdoor microalgae production (Bosma et al, 2014). 

The high oil productivity of microalgae cultures and the possible absence of competition for arable land and water resources justify the currently high... 

Table 4.2 Culture collections and suppliers of living microalgae cultures, for commercial or research purposes...

DONALDSON J (1991) Commercial production of microalgae at Coast Oyster Company, in Fulks W and Main K L (eds). Rotifer and microalgae culture systems. Honolulu, HI The Oceanic Institute, 229-239. 

Plate II Examples of microalgae culture systems used in hatcheries, (a) 2 L bottle and 10 L carboy cultures for scale-up (b) 1000 L tub cultures (c) 500 L polythene bag cultures and (d) 180 L annular photobioreactor culture. Photos (a), (b) and (c) courtesy, W. O Connor, Industry and Investment, NSW, and (d) Dion Frampton... 

Geographic location can play an important part in deciding whether microalgae culture will be effective. A temperature of 15 °C or above is considered essential for sustained algal production outdoor productivities are affected by environmental variables such as low seasonal and night-time temperatures as well as variable irradiance (Von Hamelen and Oonk, 2006). Chini Zittelli and co-workers (2003) demonstrated that a combination of natural and artificial illumination gave optimum productivities of Nannochloropsis between December and May in the continental Mediterranean climate of Italy. 

Collet, P, Helias, A., Lardon, L., et al., 2011. Life-cycle assessment of microalgae culture coupled to biogas production. Bioresource Technology 102,207-214. 

Schenk et al. (2008) mentioned that microalgae are among the most convenient sources of biodiesel due to their all-year-round availability. Microalgae cultured in an open pond was found to have a productivity that exceeds the yield of the best oilseed crops, producing 12,000 1 ha biodiesel compared with 11901 ha for rape-seed oil. 

The luke-warm water is therefore of particular interest as. a means to increase the temperature of algae suspensions. We will consider separately the case of macroalgae cultures and microalgae cultures. 

Pires JCM, Alvim-Ferraz MCM, Martins F, Simoes M. Wastewater treatment to enhance the economic viability of microalgae culture. Environ Sci Pollut Res. 2013 20 5096-5105. 

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