Use of brevibacterium sp 19-derived amidase for the synthesis of hydroxamic fatty acids

Summary Oleylhydroxamic acid (Oleyl HA) was produced by acylation of neutralized hydroxylamine with oleic acid in buffered or in solvent media using the broad-spectrum amidase activity ofBrevibacterium (BB) sp 19 cells.     

Improved Isolation of SlaA and SlaB S-layer proteins in Sulfolobus acidocaldarius

The Sulfolobus acidocaldarius S-layer is composed of two main proteins: SlaA, which forms the ordered structure of the S-layer matrix, and SlaB, which supports and anchors the S-layer into the tetraether lipid membrane. While SlaA has previously been purified by exploiting its thermotolerance and high resistance to detergents, SlaB has resisted isolation, particularly from the cell membrane. Removal of proteins other than those of the S-layer is especially difficult if large batch-scale culture volumes are unavailable. Here, we describe a benchtop-scale protocol for the purification of SlaA from S. acidocaldarius, enabling isolation of SlaB using size exclusion chromatography (gel filtration). Using this protocol, we were able to identify for the first time tetraether lipids strongly attached to SlaB via heat- and detergent-resistant interactions.

     

Proteomic Analysis of the Reproductive Organs of the Hermaphroditic Gastropod Lymnaea stagnalis Exposed to Different Endocrine Disrupting Chemicals

Many studies have reported perturbations of mollusc reproduction following exposure to low concentrations (ng/L range) of endocrine disrupting chemicals (EDCs). However, the mechanisms of action of these molecules on molluscs are still poorly understood. Investigation of the modifications of protein expression in organisms exposed to chemicals using proteomic methods can provide a broader and more comprehensive understanding of adverse impacts of pollution on organisms than conventional biochemical biomarkers (e.g., heat-shock proteins, metallothioneins, GST, EROD). In this study we have investigated the impacts of four chemicals, which exhibit different endocrine disrupting properties in vertebrates, on the proteome of the hermaphroditic freshwater pulmonate gastropod Lymnaea stagnalis after 21 days of exposure. Testosterone, tributyltin, chlordecone and cyproterone acetate were chosen as tested compounds as they can induce adverse effects on the reproduction of this snail. The 2D-DIGE method was used to identify proteins whose expression was affected by these compounds. In addition to modifying the expression of proteins involved in the structure and function of the cytoskeleton, chemicals had impacts on the expression of proteins involved in the reproduction of L. stagnalis. Exposure to 19.2 µg/L of chlordecone increased the abundance of ovipostatin, a peptide transmitted during mating through seminal fluid, which reduces oviposition in this species. The expression of yolk ferritin, the vitellogenin equivalent in L. stagnalis, was reduced after exposure to 94.2 ng Sn/L of tributyltin. The identification of yolk ferritin and the modification of its expression in snails exposed to chemicals were refined using western blot analysis. Our results showed that the tested compounds influenced the abundance of yolk ferritin in the reproductive organs. Alteration in proteins involved in reproductive pathways (e.g., ovipostatin and yolk ferritin) could constitute relevant evidence of interaction of EDCs with reproductive pathways that are under the control of the endocrine system of L. stagnalis.     

Instrumental Rotation for Persistent Fetal Occiput Posterior Position: A Way to Decrease Maternal and Neonatal Injury?

Objective

To evaluate immediate perineal and neonatal morbidity associated with instrumental rotations performed with Thierry’s spatulas for the management of persistent posterior occiput (OP) positions.

Methods

Retrospective study including all persistent occiput posterior positions with vaginal OP delivery, from August 2006 to September 2007. Occiput anterior deliveries following successful instrumental rotation were included as well. We compared maternal and neonatal immediate outcomes between spontaneous deliveries, rotational and non rotational assisted deliveries, using χ² and Anova tests.

Results

157 patients were enrolled, comprising 46 OP spontaneous deliveries, 58 assisted OP deliveries and 53 deliveries after rotational procedure. Instrumental rotation failed in 9 cases. Mean age and parity were significantly higher in the spontaneous delivery group, while labor duration was shorter. There were no significant differences in the rate of severe perineal tears and neonatal adverse outcomes between the 3 groups.

Conclusion

Instrumental rotation using Thierry’s spatulas was not associated with a reduced risk of maternal and neonatal morbidity for persistent OP deliveries. Further studies are required to define the true interest of such procedure in modern obstetrics.     

Ascertaining the biochemical function of an essential pectin methylesterase in the gut microbe Bacteroides thetaiotaomicron

Pectins are a major dietary nutrient source for the human gut microbiota. The prominent gut microbe Bacteroides thetaiotaomicron was recently shown to encode the founding member (BT1017) of a new family of pectin methylesterases essential for the metabolism of the complex pectin rhamnogalacturonan-II (RG-II). However, biochemical and structural knowledge of this family is lacking. Here, we showed that BT1017 is critical for the metabolism of an RG-II–derived oligosaccharide ΔBT1017oligoB generated by a BT1017 deletion mutant (ΔBT1017) during growth on carbohydrate extract from apple juice. Structural analyses of ΔBT1017oligoB using a combination of enzymatic, mass spectrometric, and NMR approaches revealed that it is a bimethylated nonaoligosaccharide (GlcA-β1,4-(2-O-Me-Xyl-α1,3)-Fuc-α1,4-(GalA-β1,3)-Rha-α1,3-Api-β1,2-(Araf-α1,3)-(GalA-α1,4)-GalA) containing components of the RG-II backbone and its side chains. We showed that the catalytic module of BT1017 adopts an α/β-hydrolase fold, consisting of a central twisted 10-stranded β-sheet sandwiched by several α-helices. This constitutes a new fold for pectin methylesterases, which are predominantly right-handed β-helical proteins. Bioinformatic analyses revealed that the family is dominated by sequences from prominent genera of the human gut microbiota, including Bacteroides and Prevotella. Our re-sults not only highlight the critical role played by this family of enzymes in pectin metabolism but also provide new insights into the molecular basis of the adaptation of B. thetaiotaomicron to the human gut.     

Turkey as a crossroad for Greater Flamingos Phoenicopterus roseus: evidence from population trends and ring-resightings (Aves: Phoenicopteridae)

The Greater Flamingo Phoenicopterus roseus is a waterbird commonly found in saline and brackish lagoons throughout the Mediterranean Region. We have gathered existing data on Greater Flamingos in Turkey and carried out field surveys to present the most up to date information on wintering (1999–2014) and breeding (1969– 2014). The wintering population of flamingos shows an increasing trend with 54,947±20,794 individuals mainly concentrated in the Gediz, Büyük Menderes and Çukurova deltas, respectively. Breeding attempts were recorded in at least seven wetlands in Turkey in the past, yet after 1999 most of the colonies were abandoned due to basin scale intensive water management practices in Central Anatolia. Currently, only Tuz Lake and Gediz Delta are used as regular breeding sites, while breeding has been recorded sporadically in Ac?göl and Ak?ehir Lakes. The breeding colony of Tuz Lake is of prime importance at the Mediterranean scale, with the number of young chicks in 2011, 2012 and 2013 accounting for the highest number of fledglings in the Mediterranean Region and West Africa (18,418, 20,274 and 20,292 respectively). Finally, building upon the previous findings about Turkey and the western Mediterranean metapopulation links, recent resightings of Turkish flamingos (despite the limited numbers) confirm post-fledging and natal dispersal reaching the western Mediterranean Basin and West Africa. Flamingos from Turkey were also found to disperse to Israel and to a region outside the known flyways of the western Mediterranean and West African flamingos (i.e. to Israel and UAE). Thus, Turkey, due to its geographic position, appears to be a crossroad between the western and eastern Mediterranean Region and southwest Asia.