E [168]. Certainly, numerous microalgae possess the capacity to generate substantial amounts (i.e., 20 0 dry cell weight) of TAG beneath stress situations, such as higher light, alkaline pH, and nutrient depletion, reaching up to 80 in some species [19,20]. Even so, most commonly, nutrient starvation induced cessation of cellgrowth and accumulation of storage lipid (TAG),Mar. Drugs 2013,containing mainly SFA and MUFA, as opposed to PUFA [6]. Thus, the percentage of PUFA relative to total fatty acids inside the biomass, for example EPA, ordinarily reduce below nutrient limitation [17,21,22]. Maximal PUFA levels are observed through the early stationary phase, and decrease all through the stationary phase, with parallel increases inside the proportions of SFA and MUFA, such as 14:0, 16:0, and 16:1 fatty acids [18,23,24]. Though it is actually wellknown that nutrient limitation can increase lipid content and common trends in fatty acid profiles are recognized, responses are mostly speciesspecific [257]. P. lutheri is amongst the handful of species, reported so far, where EPA and DHA levels improved in both the total and TAG fatty acid extracts on the transition to the stationary phase [10]. An adequate supply of inorganic carbon is also important to maintain photosynthetic, carbon fixation and, hence, development in photoautotrophic microalgae. Microalgae that grow photoautotrophically use inorganic carbon sources to synthesize, de novo, their own organic carbon compounds [28] and inorganic carbon availability represents a limiting issue in algal production. Cultures, for that reason, require a supplementation, which is frequently accomplished using CO2enriched air. Within this context, most research have focused on the impact of gaseous CO2 addition on growth, lipid production, and biochemical composition in microalgal cultures [293]. The presence of higher levels of CO2 has been shown to promote the production of biomass and lipids in microalgal cells [33,34]. Nevertheless, as a result of low solubility and low retention instances of CO2 in the culture media [35], quite a few authors not too long ago investigated the effects of sodium bicarbonate as an inorganic carbon supply to stimulate growth and TAG accumulation [361].Methyl 5-bromo-1H-pyrazole-3-carboxylate structure Their outcomes clearly indicate that sodium bicarbonate addition is really a promising tactic to raise biomass and oil accumulation in some microalgae.1018295-42-5 Chemical name By way of example, the effect of bicarbonate addition has been demonstrated to become an efficient lipid accumulation trigger on two distinct species of algae: the green alga Scenedesmus sp.PMID:33461880 strain WC1, as well as the marine diatom P. tricornutum [37]. Indeed, bicarbonate addition has been made use of to enhance pH and total dissolved inorganic carbon near the time of nitrate depletion. Independently of carbon levels, high pH pressure also resulted in TAG accumulation in diverse species of Chlorophyta, and, especially, for the duration of nitrogen limitation [42,43]. Nonetheless, it’s nevertheless unclear no matter whether nutrient depletion can induce lipid and TAG accumulation under a low carbon provide. Peng et al. (2013) showed that cell development and accumulation of cellular lipids in P. tricornutum CCMP632 appeared to rely completely on the fixation of external inorganic carbon below nutrientstress, with no alterations below carbon limitation but significant increases beneath carbon sufficiency [41]. Additionally, levels of TAG have been still synthesized and accumulated below inorganic carbon limitation, coinciding using a cessation in cell growth and cellular lipid accumulation [41]. Apart from the variables triggering l.