Growth, photosynthetic efficiency, and biochemical composition of Tetraselmis suecica F&M‐M33 grown with LEDs of different colors

Abstract

The effect of light quality on cell size and cell cycle, growth rate, productivity, photosynthetic efficiency and biomass composition of the marine prasinophyte Tetraselmis suecica F&M-M33 grown in 2-L flat panel photobioreactors illuminated with light emitting diodes (LEDs) of different colors was investigated. Biomass productivity and photosynthetic efficiency were comparable between white and red light, while under blue and green light productivity decreased to less than half and photosynthetic efficiency to about one third. Differences in cell size and number correlated with the cell cycle phase. Under red light cells were smaller and more motile. Chlorophyll content was strongly reduced with red and enhanced with blue light, while carotenoids and gross biomass composition were not affected by light quality. The eicosapentaenoic acid content increased under red light. Red light can substitute white light without affecting productivity of T. suecica F&M-M33, leading to smaller and more motile cells and increased eicosapentaenoic acid content. Red LEDs can thus be profitably used for the production of this microalga for aquaculture.

Tetraselmis suecica F&M‐M33 growth is influenced by its associated bacteria

“…At the beginning of the trial, all the cultures showed a similar biochemical composition (proteins 40%–47% of dry biomass, carbohydrates 9%–12%, lipids 21%–24%, ashes 16%–18%), typical of T. suecica F&M‐M33 biomass grown in a nutrient‐replete medium (high protein and low carbohydrate content) (see Abiusi et al ., 2014 for typical composition). At the end of the trial (day 14), when nitrate nitrogen was completely exhausted in all the cultures, all the biomasses showed a composition typical of nutrient‐starved conditions (high carbohydrate and low protein content) (see Bondioli et al ., 2012 for starved biomass composition).…”

“…This microalga is one of the few actually in the market, as it is widely used in aquaculture (Abiusi et al ., 2014; Tredici et al ., 2009; Tulli et al ., 2012; Muller‐Feuga, 2013). Tetraselmis also represents a possible feedstock for biofuel production (Rodolfi et al ., 2009; Bondioli et al ., 2012; Biondi et al ., 2016), cosmetic applications (Pertile et al ., 2010) and also food as the species Tetraselmis chuii has recently been approved as novel food in the EU (AECOSAN, 2014).…”

Effect of different light spectra on the growth and productivity of acclimated Nannochloropsis sp. (Eustigmatophyceae)

“…Many recent studies have shown that microalgae grown under monochromatic blue or red light exhibited similar or enhanced growth and productivity rates when compared to that of multi-chromatic white light [1][2][3]36]. By using selective wavelengths of incident light which are complementary or at least close to the maximum absorption of microalgae pigmentation, the use of other wavelengths which are poorly absorbed by the alga is avoided [1,27].…”

“…By using selective wavelengths of incident light which are complementary or at least close to the maximum absorption of microalgae pigmentation, the use of other wavelengths which are poorly absorbed by the alga is avoided [1,27]. This added advantage is why many indoor microalgal photobioreactors are being designed and equipped with light emitting diodes (LEDs) which are currently the only efficient tool capable of emitting narrow bands of monochromatic light while including other advantages such as lower heat emission, higher conversion efficiency and also a much longer life-span when compared to common fluorescent or halogen lamps [7].…”

Antenna size reduction in microalgae mass culture

“…When supplying narrow-beam LED light (small peak width) at high light intensities, it is the wavelength specific absorption capacity of the algae that determines the extent of photosystem saturation and, consequently, the light use efficiency. Although there is a strong and prevalent agreement that red and blue light are optimal for algal cultivation because of the corresponding peaks in the algal absorption spectrum (Wilhelm et al 1985, Baba et al 2012, Kim et al 2013, Abiusi et al 2014, Schulze et al 2014, Wang et al 2014, the opposite could possibly be true for high density cultures. In dilute cultures, not all incoming light energy is absorbed and, therefore, light absorption is the limiting factor for maximizing productivity.…”