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Degradation of long-chain fatty acids (LCFAs) in methanogenic environments is a syntrophic process involving the activity of LCFA-degrading bacteria and hydrogen-utilizing methanogens. If methanogens are inhibited, other hydrogen scavengers are needed to achieve complete LCFA degradation. In this work, we developed two different oleate (C18:1 LCFA)-degrading anaerobic enrichment cultures, one methanogenic (ME) and another in which methanogenesis was inhibited (IE). Inhibition of methanogens was attained by adding a solution of 2-bromoethanesulfonate (BrES), which turned out to consist of a mixture of BrES and isethionate. Approximately 5 times faster oleate degradation was accomplished by the IE culture compared with the ME culture. A bacterium closely related to Syntrophomonas zehnderi (99% 16S rRNA gene identity) was the main oleate degrader in both enrichments, in syntrophic relationship with hydrogenotrophic methanogens from the genera Methanobacterium and Methanoculleus (in ME culture) or with a bacterium closely related to Desulfovibrio aminophilus (in IE culture). A Desulfovibrio species was isolated, and its ability to utilize hydrogen was confirmed. This bacterium converted isethionate to acetate and sulfide, with or without hydrogen as electron donor. This bacterium also utilized BrES but only after 3 months of incubation. Our study shows that syntrophic oleate degradation can be coupled to desulfonation.IMPORTANCE In anaerobic treatment of complex wastewater containing fat, oils, and grease, high long-chain fatty acid (LCFA) concentrations may inhibit microbial communities, particularly those of methanogens. Here, we investigated if anaerobic degradation of LCFAs can proceed when methanogens are inhibited and in the absence of typical external electron acceptors, such as nitrate, iron, or sulfate. Inhibition studies were performed with the methanogenic inhibitor 2-bromoethanesulfonate (BrES). We noticed that, after autoclaving, BrES underwent partial hydr

peer-reviewed, Sulphonates are often the major form of sulphur in soils where sulphate usually represents less than 5% of the total sulphur. The use of sulphonates as a S source is limited to a functional bacterial guild. However, fungi may assist bacteria in sulphonate desulphurization. In this study, grassland turfs were watered periodically with a modified Hoagland's solution that was i) sulphur free, ii) contained low molecular weight sulphonate iii) or high molecular weight sulphonate. DNA fingerprint analyses of fungal and bacterial communities revealed significant differences between the rhizosphere soil and the bulk soil. Sulphonate treatments had only significant effects on the bacterial and desulphonating bacterial communities and no significant effects on the fungal communities. However, sequencing of the fungal ITS region identified the presence of potentially endophytic fungi in sulphonate amended turfs. Analysis of the sulphur species in soil suggested that the added toluenesulphonate-sulphur was transformed despite the fact that the number of the desulphonating bacteria remained unchanged indicating no sulphonate limitation. The results showcase a robust fungal community in grassland turfs where only the bacterial community with its desulphonating bacterial guild is predominantly responding to the sulphonate amendment. (C) 2013 Elsevier Masson SAS. All rights reserved., ACCEPTED, peer-reviewed

peer-reviewed, Sulfonates are major soil sulfur components that can be desulfurized by certain soil-borne bacteria as a sulfur source, but application of sulfate through fertilization could affect this natural sulfur mobilizing process. This study investigates the effects of sulfate treatments on bacterial communities in semi-natural grasslands. Agrostis stolonifera-dominated turfs with their autochthonous bacteria from Woburn Experimental Farm, UK, were incubated with and without additional sulfate over a period of eight weeks and compared to soil and rhizosphere samples taken from the field directly. Cultivable rhizobacteria able to desulfurize toluenesulfonate were dominated by strains affiliated to the Variovorax, Polaromonas and Rhodococcus genera. The betaproteobacteria communities (16S rRNA gene-based denaturing gradient gel electrophoresis) and the desulfonating bacterial communities (asfA based terminal restriction fragment length polymorphism) revealed clear differences between field rhizospheres and bulk soil and the two types of incubated rhizospheres. Clone libraries of asfA from the sulfate-limited treatment were dominated by a new AsfA type, affiliated to Polaromonas. The results from this study suggest that the community of desulfonating bacteria in the Agrostis rhizosphere adapts quickly to changing levels of inorganic sulfate., SUBMITTED, peer-reviewed

Pure 2,4 DNT-3- and -5-SO3Na were prepared from 2,3,4- and 2,4,5-TNT, respectively, and a procedure was developed for their extraction (as a mixture) from red water. Reactions of the sulfonates were studied, with special emphasis on direct and indirect methods for desulfonating them to 2,4-DNT. Reactions studied also included reduction of the nitro groups, followed by desulfonation to 2,4-DAT; heating with sulfur dioxide (giving 2-amino-4-nitrotoluene by partial reduction and desulfonation); and replacement of the sulfonate group by chlorine, hydroxyl, sulfur, cyano, and various substituted amino groups. Most of these reactions with pure sulfonates were also applied to the corresponding TNT isomers, and in some cases directly to red water. The economic feasibility of 2,4-DAT recovery was considered. Also discussed were recent studies on the recovery of TNM from TNT process gas, and the recovery of TNB from TNT oxidation products.