High-performance countercurrent chromatography for lutein production from a chlorophyll-deficient strain of the microalgae Parachlorella kessleri HY1

Green microalgae are a recognized lutein source; however, processing for lutein production requires additional operations such as extraction and saponification, mainly due to the high green pigment and lipid content in the biomass. In this study lutein was isolated from a chlorophyll-deficient Parachlorella kessleri HY1 strain using high-performance countercurrent chromatography (HPCCC). The lower phase of the biphasic solvent system composed of n-heptane–ethanol–water, 5:4:1.5, v/v/v was used both as biomass extraction solvent and HPCCC mobile phase conferring a high selectivity to the lutein production process. For the HPCCC isolation, a multiple injection method was developed, and ten consecutive sample injections (300 mg per each) were performed. To favor the economics of the process, the HPCCC mobile and stationary phases were separately formulated based on nuclear magnetic resonance (NMR) analyses. This strategy enabled to avoid obtaining immiscible liquid phases from their parent biphasic solvent system, which led to the reduction of the separation process duration and solvent consumption. Overall, 3 g of P. kessleri HY1 strain extract was processed by HPCCC yielding 150 mg of lutein (95% purity, 97% recovery). The results presented here form an efficient and economical basis for the large-scale production of microalgae-sourced lutein.

     

Molecular phylogeny of the fungus gnat family Diadocidiidae and its position within the infraorder Bibionomorpha (Diptera)

The molecular phylogeny of the family Diadocidiidae (Diptera: Sciaroidea) is reconstructed based on the combined analysis of four mitochondrial (12S, 16S, COI, cytB) and two nuclear (28S, ITS2) gene markers. All the analyses strongly support Diadocidiidae as a monophyletic group. Genus Diadocidia Ruthe, 1831 includes monophyletic subgenera Diadocidia s. str. and Taidocidia Papp and ?ev?ík (Acta Zoologica Academiae Scientiarum Hungaricae, 51 , 2005b, 329). The monophyly of Adidocidia La?tovka & Matile, 1972 was not confirmed. The position of Diadocidiidae and relationships of the families within the infraorder Bibionomorpha are demonstrated in the analyses based on three gene markers (28S, 12S and 16S). The Bayesian and maximum likelihood analyses of 10 families of Bibionomorpha revealed Sciaridae as the closest relative of Diadocidiidae. Most of the currently recognised extant families of Bibionomorpha proved to be monophyletic. The family Keroplatidae revealed as paraphyletic, with the genera of Macrocerinae being more related to Cecidomyiidae, but the support is low.