.6 and 4.two .3 of TFA, respectively (Table 1). These benefits are in agreement with many studies showing that in most species, levels of PUFA like EPA decreased under nutrient limitation with parallel increases in the proportions of SFA and/or MUFA [17,18,224]. This could be explained by the truth that nitrate starvation induces storage lipid (TAG) accumulation, which includes mainly SFA and MUFA rather than PUFA [6]. In addition, adjustments in fatty acid composition in algae are frequently associated to the proportions in the various lipid classes, which have distinctive fatty acid profiles [36,56,57]. Breuer et al. (2012) recommended that the accumulation of TAG having a distinctive fatty acid composition than that of functional and structural lipids in the oleaginous strains, or even a shift in lipid class composition (e.g., reduction in thylakoid membrane content) in nonoleaginous strains, could explain these variations upon nitrogen starvation [20]. So as to highlight this particular issue, additional information will probably be offered in the following sections (cf. Sections two.3 and 2.four) with regards to the combined effect of bicarbonate addition and nitrate limitation on TAG accumulation and TAG fatty acid composition of P. lutheri. Surprisingly, for the duration of batch cultivation of P. lutheri below a relative high light (240 photons m2 s1), EPA and DHA levels have been increasing following nitrate depletion in each total and TAG fatty acid extracts [10]. Previously, the percentage of EPA and DHA in neutral lipids of P. lutheri happen to be reported to increase with lightMar. Drugs 2013,intensity [36], highlighting the importance of factors for instance light and temperature associated to those promoting TAG accumulation on LCPUFA synthesis and partitioning into lipid classes. pH increases with culture age, particularly with bicarbonate addition, may possibly also contribute towards the fatty acid changes observed in P. lutheri after nitrate depletion. Table 1. Total fatty acid profile and content material in batch culture of P. lutheri supplemented with distinctive initial bicarbonate concentrations.Bicarbonate (mM) Just before NLimitation Fatty Acids ( TFA) 14:0 16:0 18:0 Sum of SFA 16:1 n7 18:1 n7 18:1 n9 Sum of MUFA 18:2 n6 18:three n6 18:three n3 18:four n3 20:four n6 20:five n3 22:5 n3 22:6 n3 Sum of PUFA Other individuals n3 n6 TFA (pg cell ) TFA (mg L )1 Right after NLimitation 18 15.1243313-06-5 Order 5 .8 19.0 .0 two.7 .five 37.2 .2 17.9 .5 1.3 .1 2.0 .1 21.2 .3 1.four .3 tr. 0.four .1 7.two .four 0.9 .2 18.7 .1 0.six .0 eight.six .5 37.9 .9 3.7 .6 35.5 .1 2.three .1 two.168892-66-8 custom synthesis eight .PMID:24733396 three 14.9 .9 2 14.three .three 26.two .1 0.6 .0 41.1 .2 30.3 .1 1.five .1 2.1 .1 33.9 .3 1.6 .1 tr. 0.7 .0 2.0 .0 0.9 .3 11.6 .two 1.two .1 five.three .1 23.4 .five 1.6 .1 20.1 .3 3.3 .three two.5 .1 57.7 .9 9 13.eight .three 27.4 .eight 1.5 .three 42.6 .two 29.four .six two.two .two two.9 .2 34.4 .eight 2.0 .1 0.3 .0 0.8 .1 two.0 .two 1.0 .1 9.eight .6 1.1 .1 4.three .3 21.three .1 1.5 .1 18.1 .1 3.three .1 3.8 .five 85.eight .two 18 14.7 .three 29.9 .9 0.7 .two 45.3 .6 29.3 .six 1.4 .1 1.five .2 32.2 .4 1.9 .two tr. 0.six .0 two.6 .1 0.eight .two 9.4 .0 1.five .3 4.2 .4 21.0 .six 1.five .1 18.three .two two.7 .3 six.9 .0 71.9 0.two 17.three .7 18.five .1 two.1 .8 37.eight .4 24.6 .0 1.3 .2 2.0 .1 27.8 .9 0.eight .1 tr. 1.1 .3 four.0 .5 0.8 .1 16.1 .two 0.eight .3 9.0 .three 32.three .5 2.0 .four 29.9 .eight 2.four .four 2.2 .1 13.0 .9 15.2 .7 19.7 .three 1.9 .2 36.9 .0 20.two .three 1.0 .1 2.six .6 23.9 .four 1.two .2 0.6 .1 1.1 .two 5.7 .1 0.six .three 16.five .4 0.9 .2 9.6 .four 36.1 .4 3.two .3 33.8 .5 2.3 .two two.0 .2 17.two .Saturated fatty acidsMonounsaturated fatty acidsPolyunsaturated fatty acidsResults are expressed as the imply SD of 3 replicates (n = three). tr., traces; MUFA, monounsaturated fatty acids; PUFA, polyunsaturated fatty ac.