Occurrence and distribution of ladderane oxidation products in different oceanic regimes

Ladderane fatty acids are commonly used as biomarkers for bacteria involved in anaerobic ammonium oxidation (anammox). These lipids have been experimentally shown to undergo aerobic microbial degradation to form short chain ladderane fatty acids. However, nothing is known of the production or the distribution of these oxic biodegradation products in the natural environment. In this study, we analysed marine water column particulate matter and sediment from three different oceanic regimes for the presence of ladderane oxidation products (C-14 ladderane fatty acids) and of original ladderane fatty acids (C-18 and C-20 ladderane fatty acids). We found that ladderane oxidation products, i.e. C-14 ladderane fatty acids, are already produced within the water column of the Arabian Sea oxygen minimum zone (OMZ) and thus only low amounts of oxygen (< 3 mu M) are needed for the beta-oxidation of original ladderane fatty acids to proceed. However, no short chain ladderane fatty acids were detected in the Cariaco Basin water column, where oxygen concentrations were below detection limit, suggesting that the beta-oxidation pathway is inhibited by the absence of molecular oxygen, or that the microbes performing the degradation are not proliferating under these conditions. Comparison of distributions of ladderane fatty acids indicates that short chain ladderane fatty acids are mostly produced in the water column and at the sediment surface, before being preserved deeper in the sediments. Short chain ladderane fatty acids were abundant in Arabian Sea and Peru Margin sediments (ODP Leg 201), often in higher concentrations than the original ladderane fatty acids. In a sediment core taken from within the Arabian Sea OMZ, short chain ladderanes made up more than 90% of the total ladderanes at depths greater than 5 cm below sea floor. We also found short chain ladderanes in higher concentrations in hydrolysed sediment residues compared to those freely occurring in lipid extracts, suggesting that they had become bound to the sediment matrix. Furthermore, these matrix-bound short chain ladderanes were found at greater sediment depths than short chain ladderanes in the lipid extract, suggesting that binding to the sediment matrix aids the preservation of these lipids. Though sedimentary degradation of short chain ladderane fatty acids did occur, it appeared to be at a slower rate than that of the original ladderane fatty acids, and short chain ladderane fatty acids were found in sediments from the Late Pleistocene (similar to 100 kyr). Together these results suggest that the oxic degradation products of ladderane fatty acids may be suitable biomarkers for past anammox activity in OMZs

Sephardim in Shanghai

In Shanghai bildete sich nach dem Opiumkrieg (1840-42) eine kleine Gemeinde von Bagdader Juden, die bis zur Gründung der Volksrepublik China im Jahre 1949 bestand. Diese Juden waren in den dreißiger Jahren des 19. Jahrhunderts vor den Verfolgungen im Osmanischen Reiche geflohen und zunächst in die unter englischer Herrschaft stehenden indischen Städte Bombay und Kalkutta übergesiedelt. Nach dem Opiumkrieg stiegen sie in Shanghai in den Opiumhandel ein und erzielten damit bis zum Ende des 19. Jahrhunderts hohe Gewinne. Im 20. Jahrhundert investierten sie ihr Kapital in den Immobilienhandel, in die Industrie und in gemeinnützige Unternehmen und einige von ihnen machten damit legendäre Gewinne. Die Zahl der in Shanghai lebenden Bagdader Juden betrug gegen Ende des 19. Jahrhundeds 175 und wuchs danach in der Zeit bis zum Ersten Weltkrieg auf ca. 800. Im Jahre 1909 gündeten diese Juden die Shanghai Jewish Communal Association. Dieser Verein stellte armen Juden koscheres Essen, Ausbildungsmöglichkeiten und medizinische Versorgung zur Verfügung. Die Gemeinde der Bagdader Juden legte grölßten Wert auf gute Beziehungen zu den Engländern, die in Shanghai, genauer gesagt in der internationalen Niederlassung, die politische Führung innehatten. Sehr reiche Juden erworben auch die englische Staatsangehörigkeit. Um als Europäer angesehen zu werden, bezeichneten sie sich in Shanghai als „Sephardim\u27\u22 ein Begriff, der ursprünglich den Juden aus Spanien und Portugal galt. Trotz ihrer kulturellen Anpassung an die englische Gesellschaft, bemühten sie sich ihre Identität als Bagdader Juden beizubehalten, was für sie als Minderheit innerhalb der Ausländergesellschak in der chineischen Großstadt Shanghai unentbehrlich war. Außerdem zeigten sie große Solidarität mit ihren Glaubensbnidern. Sie versuchten die damals vom Aussterben bedrohte Judengemeinde in Kaifeng zu retten. Sie unterstützten auch die eben entstandene Zionismusbewegung mit politischen, aber noch mehr mit finanziellen Mitteln. Und in Shanghai halfen sie 22.000 jüdischen Hüchtlingen aus Russland, Deutschland, Österreich und Polen

Biomarker evidence for the occurrence of anaerobic ammonium oxidation in the eastern Mediterranean Sea during Quaternary and Pliocene sapropel formation

The eastern Mediterranean Sea sedimentary record is characterised by intervals of organic-rich sapropel sediments, indicating periods of severe anoxia triggered by astronomical forcing. It has been hypothesised that nitrogen fixation was crucial in injecting the Mediterranean Sea with bioavailable nitrogen (N) during sapropel events. However, the evolution of the N biogeochemical cycle of sapropels is poorly understood. For example, the role of the complementary removal reactions like anaerobic ammonium oxidation (anammox) has not been investigated because the traditional lipid biomarkers for anammox, ladderane fatty acids, are not stable over long periods in the sedimentary record. Using an alternative lipid biomarker for anammox, bacteriohopanetetrol stereoisomer (BHT isomer), we present here for the first time N removal throughout the progression, e.g. formation, propagation, and termination, of basin-wide anoxic events. BHT isomer and ladderanes were analysed in sapropel records taken from three eastern Mediterranean sediment cores, spanning S1 to Pliocene sapropels. Ladderanes were rapidly degraded in sediments, as recently as the S5 sapropel. BHT isomer, however, was present in all sapropel sediments, as far back as the Pliocene, and clearly showed the response of anammox bacteria to marine water column redox shifts in high-resolution records. Two different N removal scenarios were observed in Mediterranean sapropels. During S5, anammox experienced Black Sea-type water column conditions, with the peak of BHT isomer coinciding with the core of the sapropel. Under the alternative scenario observed in the Pliocene sapropel, the anammox biomarker peaked at onset and termination of said sapropel, which may indicate sulfide inhibition of anammox during the core of sapropel deposition. This study shows the use of BHT isomer as a biomarker for anammox in the marine sediment record and highlights its potential in reconstructing anammox during past anoxic events that are too old for ladderanes to be applied, e.g. the history of oxygen minimum zone expansion and oceanic anoxic events

Distributions of bacteriohopanepolyols in lakes and coastal lagoons of the Azores Archipelago

Bacteriohopanepolyols (BHPs) are a diverse class of lipids produced by bacteria across a wide range of environments. In this study, we aim to further identify BHPs related to ecological niches and/or specific bacteria by characterizing the distribution of BHPs in suspended particulate matter (SPM) of the water column and in sediments in a range of lakes and coastal lagoons from the Azores Archipelago, as well as in a co-culture enriched for methanotrophs. Sediment samples from Azorean lakes with low-oxygen conditions during the summer months (i.e., Azul, Verde, Funda, and Negra) contain relatively high abundances of BHPs that are typically associated with methane-oxidizing (methanotrophic) bacteria (i.e., aminotetrol, aminopentol, and methylcarbamate-aminopentol), as well as the ethenolamine-BHPs (i.e., ethenolamine-BHpentol and ethenolamine-BHhexol) and the N-formylated aminoBHPs. Both ethenolamine-BHPs and N-formylated aminoBHPs were also detected in a methanotroph-methylotroph co-culture that was enriched from a lake. In the SPM of all water columns, bacteriohopanetetrol (BHT), BHT cyclitol ether, and aminotriol are the dominant BHPs. In SPM from Lake Funda, nucleoside BHPs (i.e., Me-adenosylhopaneHG-diMe (where HG refers to head group), N1-methylinosylhopane, 2Me-N1-inosylhopane, and Me-N1-inosylhopane) are present in low abundance or absent under oxic conditions but increase in concentration near the chemocline, suggesting potential in situ production of these nucleoside BHPs rather than an allochthonous origin. In contrast, sediments from shallow, well-mixed lakes (i.e., Empadadas, São Jorge, and Lomba) contain higher abundances of adenosylhopane and N1-methylinosylhopane, which likely originate from bacteria living in nearby soils. Based on our current results we revised the existing Rsoil index, which was previously used to infer terrestrial inputs to aquatic environments, to exclude any potential nucleosides produced in the lake water column (Rsoil-lake). In the coastal lagoons, Cubres East and Cubres West, methoxylated BHTs were detected, and higher abundances of ethenolamine-BHT were observed. This study highlights the diversity of BHPs in lakes and coastal lagoons and their potential as taxonomic markers for bacteria associated with certain ecological niches, which can be preserved in sedimentary records.</p

Effect of antenatal dietary interventions in maternal obesity on pregnancy weight-gain and birthweight: Healthy Mums and Babies (HUMBA) randomized trial

Background: Pregnancy interventions that improve maternal and infant outcomes are urgently needed in populations with high rates of obesity. We undertook the Healthy Mums and Babies (HUMBA) randomized controlled trial to assess the effect of dietary interventions and or probiotics in a multiethnic population of pregnant women with obesity, living in an area of high deprivation. Objectives: To determine whether a culturally tailored dietary intervention and or daily probiotic capsules in pregnant women with obesity reduces the co-primary outcomes of (1) excessive gestational weight gain (mean >0.27 kg/week) and (2) birthweight. Study Design: We conducted a 2 × 2 factorial, randomized controlled trial in women without diabetes at pregnancy booking, body mass index ≥30 kg/m2, and a singleton pregnancy. At 12+0 to 17+6 weeks' gestation, eligible women were randomized to a dietary intervention (4 tailored educational sessions at ≤28 weeks' gestation by a community health worker trained in key aspects of pregnancy nutrition plus text messaging until birth) or to routine dietary advice; and to daily capsules containing either (Lactobacillus rhamnosus GG and Bifidobacterium lactis BB12, minimum 6.5 × 109 colony forming units), or placebo, until birth. Analysis was by intention to treat with adjustment for maternal baseline body mass index. Infant outcomes were additionally adjusted for ethnicity, sex, and gestational age at birth. Results: In total, 230 women were recruited between April 2015 and June 2017 (dietary intervention N = 116 vs routine dietary advice N = 114; probiotics N = 115 vs placebo N = 115). Baseline characteristics and demographic variables were similar across all groups. There was no significant difference between intervention groups, for the co-primary outcomes of (1) proportion of women with excessive gestational weight gain (dietary intervention vs routine advice: 79/107 [73.8%] vs 90/110 [81.8%], adjusted relative risk [relative risk, 0.92; 95% confidence interval, 0.80-1.05]; probiotics versus placebo: 89/108 [82.4%] and 80/109 [73.4%], relative risk, 1.14, 95% confidence interval, 0.99-1.31) or (2) birthweight (dietary intervention vs routine advice: 3575 vs 3612 g, adjusted mean difference, -24 g, 95% confidence interval, -146 to 97; probiotics vs placebo: 3685 vs 3504 g, adjusted mean difference, 107 g, 95% confidence interval, -14 to 228). Total maternal weight gain, a secondary outcome, was lower with dietary intervention compared with routine dietary advice (9.7 vs 11.4 kg, adjusted mean difference, -1.76, 95% confidence interval, -3.55 to 0.03). There were no significant differences between intervention groups in other secondary maternal or neonatal outcomes. Conclusion: Although dietary education and or probiotics did not alter rates of excessive gestational weight gain or birthweight in this multiethnic, high-deprivation population of pregnant women with obesity, dietary education was associated with a modest reduction in total weight gain with potential future benefit for the health of mothers and their offspring if sustained.Karaponi A.M. Okesene-Gafa, Minglan Li, Christopher J.D. McKinlay, Rennae S. Taylor, Elaine C. Rush, Clare R. Wall, Jess Wilson, Rinki Murphy, Rachael Taylor, John M.D. Thompson, Caroline A. Crowther, Lesley M.E. McCowa