Induction of triacylglycerol production in Chlamydomonas reinhardtii: comparative analysis of different element regimes.

In this study, impacts of different element absence (nitrogen, sulfur, phosphorus and magnesium) and supplementation (nitrogen and zinc) on element uptake and triacylglycerol production was followed in wild type Chlamydomonas reinhardtii CC-124 strain. Macro- and microelement composition of C. reinhardtii greatly differed under element regimes studied. In particular, heavy metal quotas of the microalgae increased strikingly under zinc supplementation. Growth was suppressed, cell biovolume, carbohydrate, total neutral lipid and triacylglycerol levels increased when microalgae were incubated under these element regimes. Most of the intracellular space was occupied by lipid bodies under all nutrient starvations, as observed by confocal microscopy and transmission electron micrographs. Results suggest that sulfur, magnesium and phosphorus deprivations are superior to nitrogen deprivation for the induction triacylglycerol production in C. reinhardtii. On the other hand, FAME profiles of the nitrogen, sulfur and phosphorus deprived cells were found to meet the requirements of international standards for biodiesel.

Flavonoid compounds identified in Alchemilla L. species collected in the north-eastern Black Sea region of Turkey.

This study identified flavonoid glycosides in species of the genus Alchemilla, A. procerrima, A. stricta, A. hirtipedicellata and A. sericata. A. procerrima is an endemic species for Turkey. After detailed investigation, flavonoid compounds of the species were identified for the first time. In this study, flavonoid compounds were determined by using two different chromatography techniques, TLC and HPLC. The following flavonoid compounds were identified from the Alchemilla species studied. They are as follows: orientin (luteolin-8-C-glucoside) Rf: 0,70, vitexin (apigenin-8-C-glucoside) Rf: 0,77 as flavone-C-glycoside, rutin (quercetin-3-O-rutinoside) Rf: 0,44, hyperoside (quercetin-3-O-galactoside) Rf: 0,65, isoquercetin (quercetin-3-O-glucopyranoside) Rf: 0,72, quercitrin (quercetin-3-O-rhamnoside) Rf: 0,84 as flavonol-O-glycoside. Three more folavonoids with Rf values of Rf1=0,36, Rf2=0,54 and Rf3=0,68 were also identified for the first time in this study. Rutin (quercetin-3-O-rutinoside) and the flavonoid glycoside, shown as Rf2 were found in all species. Quercitrin and isoquercetin were determined in all analysed species but A. procerrima. Hyperoside was identified in all species except for A. stricta. Vitexin was determined only in A.stricta. Orientin was determined in A. procerrima and A. stricta, but could not be determined in A. sericata and A. hirtpedicellata. Unknown flavonoid with Rf1 and Rf3 were determined outside of A. sericata. Description of these compounds in Turkish Alchemilla plants for the first time should be viewed as a discovery of an important chemosystematic feature.