Influence of Light Conditions on Microalgae Growth and Content of Lipids, Carotenoids, and Fatty Acid Composition

Abstract

Microalgae are a valuable natural resource for a variety of value-added products. The growth of microalgae is determined by the impact of many factors, but, from the point of view of the implementation of autotrophic growth, light is of primary importance. This work presents an overview of the influence of light conditions on the growth of microalgae, the content of lipids, carotenoids, and the composition of fatty acids in their biomass, taking into account parameters such as the intensity, duration of lighting, and use of rays of different spectral composition. The optimal light intensity for the growth of microalgae lies in the following range: 26−400 µmol photons m−2 s−1. An increase in light intensity leads to an activation of lipid synthesis. For maximum lipid productivity, various microalgae species and strains need lighting of different intensities: from 60 to 700 µmol photons m−2 s−1. Strong light preferentially increases the triacylglyceride content. The intensity of lighting has a regulating effect on the synthesis of fatty acids, carotenoids, including β-carotene, lutein and astaxanthin. In intense lighting conditions, saturated fatty acids usually accumulate, as well as monounsaturated ones, and the number of polyunsaturated fatty acids decreases. Red as well as blue LED lighting improves the biomass productivity of microalgae of various taxonomic groups. Changing the duration of the photoperiod, the use of pulsed light can stimulate microalgae growth, the production of lipids, and carotenoids. The simultaneous use of light and other stresses contributes to a stronger effect on the productivity of algae.

The Role of Photo-Cycles in the Modulation of Growth and Biochemical Profile of Microalgae: Part I—Food Interest Compounds

“…In fact, in pulsed light experiments, cells are able to avoid photodamage and use the energy from the pulses to improve photon absorption by the photosystem. As described by Maltsev et al [ 6 ] the active functioning of the photosystem, when caused by an active change in light supply, is accompanied by an increase in the desaturation of omega-3 and 6 fatty acids. The desaturation of these fatty acids can be considered as one of the rapid adaptive responses to light pulse changes and may be associated with the “transition states” of photosystems.…”

“…In order to use microalgae as a source of product, it is important to study the influence of cultivation conditions as well as the rate of product generation [ 5 ]. Research shows that light availability is one of the main factors in microalgae growth and biomass accumulation, due to an increase in the rate of photosynthesis [ 6 , 7 ]. Indeed, in higher plants as well as in green microalgae, antenna pigment molecules bound to light-gathering complexes in the thylakoid membrane help to collect light and transfer energy to the reaction center of photosystems, e.g., PS II.…”

Investigation of Chemical Constituents of Eranthis longistipitata (Ranunculaceae): Coumarins and Furochromones

“…Mostly, these are long-chain fatty acids, octadecanoids with hydroxyl substituents, oxylipins, and hydroxypolyunsaturated fatty acids. The identified fatty acids play an important role in the metabolism of plant organisms and have various types of biological activity [ 17 , 18 ]. For example, 9-oxo-ODA, by acting on peroxisome proliferator-activated receptor, inhibits cellular triglyceride accumulation in hepatocytes and can be used against disorders of lipid metabolism [ 19 ].…”

Growth, Phycobiliproteins, Chlorophyll and Carotenoids Content of the Marine Cyanobacteria <em>Phormidium</em> sp. And <em>Cyanothece</em> sp. As Affected by White and Colored Artificial Light in Batch Cultures

“…For all microalgae (prokaryotic and eukaryotic) the culture productivity on the one hand and their biochemical composition (photosynthetic pigments included) on the other, are greatly affected by physicochemical and nutritional factors prevailing in their cultivation [20]. Among them light is of paramount importance as both its quantity (intensity) and quality (color) of the visible spectrum utilized for photosynthesis, affect profoundly the productivity of the culture and the biochemical composition of the cells [21][22][23]. As the increased interest of the world market for carotenoids from natural sources [24] and biliproteins [6,13,25] substantiate the experimentation on optimizing their production, the parameter of light emerges as a key-role factor for accomplishing that [14,19].…”

“…As the increased interest of the world market for carotenoids from natural sources [24] and biliproteins [6,13,25] substantiate the experimentation on optimizing their production, the parameter of light emerges as a key-role factor for accomplishing that [14,19]. Although cyanobacteria are limitedly mentioned in the recent review work of [23] where the influence of light on microalgae is reviewed, there are several studies that focus on the effect of light intensity and its color on growth and cell constituents of several cyanobacterial species, mainly Arthrospira [14,[26][27][28][29][30][31], Anabaena [32], Nostoc [32], Phormidium [18,19] and various other species [33][34][35][36][37]. On this ground we examined the effect of light on two locally isolated (saltworks of Messolonghi, W. Greece, [38]) cyanobacteria, the coccoid N-fixing Cyanothece sp.…”