Using different wavelengths and irradiance on the microalgae Acutodesmus obliquus batch culture

Abstract

AbstractBACKGROUNDThe quality of light, such as wavelength and the intensity affect the performance of algal growth and lipid production. Moreover, these variables also affect the lipids profile. To study the interrelation among these variables, Acutodesmus obliquus (Scenedesmus obliquus UTEX393) a microalga, was cultivated using illumination by light‐emitting‐diode surface mount device extensions emitting red (λ = 620–750 nm), yellow (λ = 570–590 nm), green (λ = 495–570 nm) and violet (λ = 380–450 nm) light. Additionally, each culture was illuminated at different light intensities (I1 = 8.75, I2 = 14.22 and I3 = 19.69 W m−2). Finally, all samples were analysed by GC‐MS.RESULTSThe results showed: (1) the biomass production is directly proportional to the light intensity, e.g. at I3 = 19.69 W m−2 violet (36.80 mg L−1), yellow (25.49 mg L−1) and red (39.44 mg L−1) showed the major production; (2) however, the lipids were produced in minor amounts at major violet light intensity (3.64 mg L−1 at I3 = 19.69 W m−2); (3) the major lipids production (20.56 mg L−1) was obtained with red light at I3 = 19.69 W m−2 and (4) A. obliquus, under the parameters established was a good producer of lipids.CONCLUSIONSThe major amount of biomass was obtained at red, yellow and violet light; meanwhile, the low biomass production, using green light, was associated with inefficient absorption of green light by chlorophyll. Additionally, palmitic, linolenic and linoleic were the most produced lipids, establishing a dependence between light wavelength and irradiance with biomass and lipid production. These results support the use of wavelengths and intensities to produce a group of specific lipids according to the needs of different industries. © 2019 Society of Chemical Industry