Stereocontrolled synthesis of (-)-galanthamine

An enantioselective synthesis of (-)-galanthamine has been realized in 11 linear steps starting from isovanillin. A Mitsunobu aryl ether forming reaction was used to assemble the galanthamine backbone, which was stitched together using enyne ring-closing metathesis, Heck, and N-alkylation reactions affording the tetracyclic ring system. Control of relative and absolute stereochemistry was derived from an easily accessible enantiomerically enriched propargylic alcohol 13

Bacteriohopanepolyol signatures as markers for methanotrophic bacteria in peat moss

Bacteriohopanepolyols (BHPs) are bacterial biomarkers with a likely potential to identify present and past methanotrophic communities. To unravel the methanotrophic community inpeat bogs, we report the BHP signatures of type I and type II methanotrophs isolated from Sphagnummosses and of an extreme acidophilic verrucomicrobial methanotroph. A type I Methylovulum-like strain (M200) contains a remarkable combination of BHPs, including a complete suite of mono-unsaturated aminobacteriohopanepentol, -tetrol and -triol. The Methylomonas-like strain (M5) mainly produces aminobacteriohopanepentol, characteristic for type I methanotrophs, and the Methylosinus-like strain (29) contains both aminobacteriohopanetetrol and aminobacteriohopanetriol, typical for a type II methanotroph. The type II methanotroph Methylocella palustris and the verrucomicrobial Methylacidiphilum fumariolicum strain SolV primarily produce aminotriol, which is also produced by many other bacteria. InSphagnummosses and underlying peat from a peat bog from Moorhouse, UK, the only detectable BHPs indicative of methanotrophs are aminobacteriohopanepentol (aminopentol) and aminobacteriohopanetetrol (aminotetrol), although both are relatively low in abundance compared to other BHPs. Aminopentol serves as a markerfor type I methanotrophs, while aminotetrol may reflect the presence of both type I and type II methanotrophs. The similar quantities of aminotetrol and aminopentol indicate that the methanotrophic community inSphagnumpeat probably consist of a combination of both type I and type II methanotrophs, which is in line with previously published pmoA-based micro-array result

Bacteriohopanepolyol signatures as markers for methanotrophic bacteria in peat moss

Bacteriohopanepolyols (BHPs) are bacterial biomarkers with a likely potential to identify present and past methanotrophic communities. To unravel the methanotrophic community inpeat bogs, we report the BHP signatures of type I and type II methanotrophs isolated from Sphagnummosses and of an extreme acidophilic verrucomicrobial methanotroph. A type I Methylovulum-like strain (M200) contains a remarkable combination of BHPs, including a complete suite of mono-unsaturated aminobacteriohopanepentol, -tetrol and -triol. The Methylomonas-like strain (M5) mainly produces aminobacteriohopanepentol, characteristic for type I methanotrophs, and the Methylosinus-like strain (29) contains both aminobacteriohopanetetrol and aminobacteriohopanetriol, typical for a type II methanotroph. The type II methanotroph Methylocella palustris and the verrucomicrobial Methylacidiphilum fumariolicum strain SolV primarily produce aminotriol, which is also produced by many other bacteria. InSphagnummosses and underlying peat from a peat bog from Moorhouse, UK, the only detectable BHPs indicative of methanotrophs are aminobacteriohopanepentol (aminopentol) and aminobacteriohopanetetrol (aminotetrol), although both are relatively low in abundance compared to other BHPs. Aminopentol serves as a markerfor type I methanotrophs, while aminotetrol may reflect the presence of both type I and type II methanotrophs. The similar quantities of aminotetrol and aminopentol indicate that the methanotrophic community inSphagnumpeat probably consist of a combination of both type I and type II methanotrophs, which is in line with previously published pmoA-based micro-array result

Evidence for complete denitrification in a benthic foraminifer

Contains fulltext : 35883.pdf (publisher's version ) (Closed access

Improved nitrogen removal by application of new nitrogen-cycle bacteria (Review)

In order to meet increasingly stringent European discharge standards, new applications and control strategies for the sustainable removal of ammonia from wastewater have to be implemented. In this paper we discuss a nitrogen removal system based on the processes of partial nitrification and anoxic ammonia oxidation (anammox). The anammox process offers great opportunities to remove ammonia in fully autotrophic systems with biomass retention. No organic carbon is needed in such nitrogen removal system, since ammonia is used as electron donor for nitrite reduction. The nitrite can be produced from ammonia in oxygen-limited biofilm systems or in continuous processes without biomass retention. For successful implementation of the combined processes, accurate biosensors for measuring ammonia and nitrite concentrations, insight in the complex microbial communities involved, and new control strategies have to be developed and evaluated. [KEYWORDS: ammonium, anammox, denitrification, nitrification,/kwd>, nitrite, planctomycetales]