Fatty Acid Biosynthesis from Chlorella in Autotrophic and Mixotrophic Cultivation

Abstract

Microalgae are photosynthetic microorganisms whose composition and biomass production can be influenced by manipulating the cultivation conditions employed. However, few studies have evaluated the effects of various cultivation conditions in autotrophic and mixotrophic conditions. The present work aimed to evaluate the effects of cultivation conditions on the cell growth and biosynthesis of fatty acids (FAs) by microalgae of the genus Chlorella in autotrophic and mixotrophic cultivation. Evaluation of the effects of the conditions was performed using an experimental design methodology. The highest values of maximum biomass concentration (Xmax) and maximum biomass productivity (Pmax) were obtained in autotrophic cultures. Palmitic acid was the FA obtained at the highest concentration in both cultivation modes. The concentrations of polyunsaturated FAs (PUFAs) ranged from 12.2 to 41.2% in autotrophic cultures and from 11 to 34.3% in the mixotrophic cultures. The variables photoperiod and sodium bicarbonate concentration showed the greatest influence on the Xmax, Pmax, and PUFA concentration in autotrophic and mixotrophic cultivations, respectively. This study verified that the selection of conditions and mode of cultivation contribute to the production of microalgal biomass and FA biosynthesis.

Toxicity and Starvation Induce Major Trophic Isotope Variation in Daphnia Individuals: A Diet Switch Experiment Using Eight Phytoplankton Species of Differing Nutritional Quality

“…Indeed, Chlorella species are known for the high variability of their biochemical composition [ 66 ]. Studies on the algal species Chlorella vulgaris showed that in addition to phytosterols, which Daphnia can convert to the required or important cholesterol, this alga also contains long-chain polyunsaturated fatty acids (PUFAs) such as ALA, EPA, and DHA [ 55 , 67 , 68 , 69 , 70 ], which are important for Daphnia . Evidently, the availability of sterols influences the somatic growth of Daphnia , while the PUFAs primarily play a crucial role in Daphnia reproduction [ 71 ].…”

Mixotrophic cultivation of Chlorella vulgaris in sugarcane molasses preceding nitrogen starvation: Biomass productivity, lipid content, and fatty acid analyses

“…16,[33][34][35] and Tetraselmis gracilis. 16,28,29,[36][37][38][39] Thus, keeping in view the significance of mixotrophic cultivation, the present study was designed to raise pure culture of C. vulgaris using molasses as a novel organic carbon source. The mixotrophically raised microalgal biomass was kept under nitrogen starvation and then processed for the extraction and analysis of fatty acids.…”

“…kessleri, C. sorokiniana , C. vulgaris , Desmodesmus ( D .) brasiliensis, D. spinosus , Graesiella sp., Haematococcus pluvialis , Messastrum gracile , Micractinium inermum , Monoraphidium sp., Nannochloropsis sp., Scenedesmus (S.) quadricauda and Tetraselmis gracilis 16,28,29,36‐39 . Thus, keeping in view the significance of mixotrophic cultivation, the present study was designed to raise pure culture of C. vulgaris using molasses as a novel organic carbon source.…”

“…Various agro‐industrial wastes are produced in massive proportions throughout the world and usually dumped in the ambient environment as point/nonpoint source pollutants 21‐27 . Such wastes are generally available at low/no cost and can be valorized as organic carbon sources for the mixotrophic cultivation of microalgae 28,29 . In this way, treatment of potentially hazardous agro‐industrial wastes and sequestration of atmospheric CO 2 can be achieved concomitantly in raising highly productive oleaginous microalgal biomass mixotrophically for the production of biofuels 30,31 .…”

“…[21][22][23][24][25][26][27] Such wastes are generally available at low/no cost and can be valorized as organic carbon sources for the mixotrophic cultivation of microalgae. 28,29 In this way, treatment of potentially hazardous agro-industrial wastes and sequestration of atmospheric CO 2 can be achieved concomitantly in raising highly productive oleaginous microalgal biomass mixotrophically for the production of biofuels. 30,31 It has been evident…”