Continuous cultivation of microalgae in photobioreactors as a source of renewable energy: Current status and future challenges

Arthrospira platensis Cultivation in a Bench-Scale Helical Tubular Photobioreactor

“…From the results of µ X listed in Table 1, one can propose the following empirical second-degree polynomial equation relating this kinetic parameter to PPFD: µ X = 0.011 PPFD − 5.0 × 10 −5 PPFD 2 (R 2 = 0.8498) (5) which, together with Equation (4), may be usefully employed to optimize this process on an industrial scale. Equations ( 4) and ( 5) allowed for estimating two different PPFD ranges (100-120 and 155-170 µmol photons m −2 s −1 ) within which cell productivity and specific growth rate reached maximum values of 0.527-0.528 g DW L −1 day −1 and 0.600-0.605 day −1 , respectively.…”

“…In this regard, intense research has been carried out on plant engineering to optimize the production system as well as on microbiological aspects to improve culture productivity through the isolation, selection, and genetic transformation of strains, with the goal of expanding the range of competitive high-value microalgal compounds [2][3][4][5]. The achievement of high productivity in microalgal mass with minimum operating costs is, in fact, fundamental to reduce the cost of valuable products and to broaden the commercial utilization of microalgae [6].…”

“…Microalgal cultivation technology has gained widespread attention because microalgae combine the renewable energy-capturing ability of photosynthesis with the high production rates of controlled microbial cultivation, which makes them potentially valuable organisms for cheap industrial production processes [5,7]. They represent the main natural source of useful and valuable molecules with numerous practical applications, for the majority of which the market is still developing; furthermore, the biotechnological use of microalgae is likely to extend to new areas.…”

“…The global climate change is, today, one of the greatest environmental concerns. It is mainly due to the emission into the atmosphere of greenhouse gases, such as CO 2 produced by the combustion of fossil fuels [5]. An attractive alternative to reduce carbon dioxide emissions could be the use of photosynthetic microorganisms able to utilize this pollutant as a carbon source for their growth [5,7].…”

“…It is mainly due to the emission into the atmosphere of greenhouse gases, such as CO 2 produced by the combustion of fossil fuels [5]. An attractive alternative to reduce carbon dioxide emissions could be the use of photosynthetic microorganisms able to utilize this pollutant as a carbon source for their growth [5,7]. From this point of view, the photoautotrophic cultivation of the cyanobacterium A. platensis would allow to produce valuable biomass using the CO 2 from industrial processes and other human activities as a carbon source [38].…”