WSF and WAFtreatments, primary productivity was reduced more in WSF than in WAF, and concentrations of transparent exopolymeric particles were highest in WSF and lowest in the controls. These differences highlight the importance of dosing strategy for mesocosm and toxicity tests.

Bernardin, M., Masle, A.L., Bessueille-Barbier, F., Lienemann, C.-P., Heinisch, S., 2020. Comprehensive two- dimensional liquid chromatography with inductively coupled plasma mass spectrometry detection for the characterization of sulfur, vanadium and nickel compounds in petroleum products. Journal of Chromatography A 1611, 460605.

http://www.sciencedirect.com/science/article/pii/S0021967319310131 The petroleum industry is increasingly concerned with the conversion of vacuum residues as a consequence of decreased conventional crude oil availability. The compositional analysis of heavy oil products has become a key step in conversion processes, but the complexity of these oil matrices tends to increase with their boiling point. In this study, comprehensive two-dimensional liquid chromatography (LCxLC) coupled to inductively coupled mass spectrometry (ICP-MS/MS) is considered with a view to meet new requirements and to bring additional information regarding the species present in these matrices. In search for a high degree of orthogonality, two separation techniques involving two different retention mechanisms were evaluated: Size Exclusion Chromatography (SEC) and Reverse Phase Liquid Chromatography (RPLC). In SEC, the analytes are separated according to their molecular weight while according to their hydrophobicity in RPLC. The separation power of both individual separation techniques was first evaluated. Off-line and on-line LCxLC were compared on the basis of an optimization approach. It is shown that off-line SECxRPLC can provide, for the same analysis time of 150 min, a higher peak capacity (2600 vs 1700) than on-line RPLCxSEC while a similar dilution factor (close to 30) but also requires far fewer fractions to be analyzed (12 vs 400). Asphaltenes which constitute the heaviest fraction of crude oils (obtained from petroleum industry) were analyzed by the developed off-line SECxRPLC method. The resulting 2D-contour plots show that co-elutions could be removed leading, for the first time, to new information on high molecular weight species containing sulfur and vanadium.

Besseling, M.A., Hopmans, E.C., Bale, N.J., Schouten, S., Sinninghe Damsté, J.S., Villanueva, L., 2020. The absence of intact polar lipid-derived GDGTs in marine waters dominated by Marine Group II: Implications for lipid biosynthesis in Archaea. Scientific Reports 10, 294.

https://doi.org/10.1038/s41598-019-57035-0 The marine pelagic archaeal community is dominated by three major groups, the marine group I (MGI) Thaumarchaeota, and the marine groups II and III (MGII and MGIII) Euryarchaeota. Studies of both MGI cultures and the environment have shown that the MGI core membrane lipids are predominantly composed of glycerol dibiphytanyl glycerol tetraether (GDGT) lipids and the diether lipid archaeol. However, there are no cultured representatives of MGII and III archaea and, therefore, both their membrane lipid composition and potential contribution to the marine archaeal lipid pool remain unknown. Here, we show that GDGTs present in suspended particulate matter of the (sub)surface waters of the North Atlantic Ocean and the coastal North Sea are derived from MGI archaea, and that MGII archaea do not significantly contribute to the pool of GDGTs and archaeol. This implies, in contrast to previous suggestions, that their lipids do not affect the widely used sea surface temperature proxy TEX . These findings also indicate that MGII archaea are not able to produce any 86 known archaeal lipids, implying that our understanding of the evolution of membrane lipid biosynthesis in Archaea is far from complete.

Bhatia, S.K., Jagtap, S.S., Bedekar, A.A., Bhatia, R.K., Patel, A.K., Pant, D., Rajesh Banu, J., Rao, C.V., Kim, Y.- G., Yang, Y.-H., 2020. Recent developments in pretreatment technologies on lignocellulosic biomass: Effect of key parameters, technological improvements, and challenges. Bioresource Technology 300, 122724.

http://www.sciencedirect.com/science/article/pii/S0960852419319534