Pharmaceuticals have emerged as a major group of environmental contaminants over the past decade but relatively little is known about their occurrence in freshwaters compared to other pollutants. We present a global-scale analysis of the presence of 203 pharmaceuticals across 41 countries and show that contamination is extensive due to widespread consumption and subsequent disposal to rivers. There are clear regional biases in current understanding with little work outside North America, Europe, and China, and no work within Africa. Within individual countries, research is biased around a small number of populated provinces/states and the majority of research effort has focused upon just 14 compounds. Most research has adopted sampling techniques that are unlikely to provide reliable and representative data. This analysis highlights locations where concentrations of antibiotics, cardiovascular drugs, painkillers, contrast media, and antiepileptic drugs have been recorded well above thresholds known to cause toxic effects in aquatic biota. Studies of pharmaceutical occurrence and effects need to be seen as a global research priority due to increasing consumption, particularly among societies with aging populations. Researchers in all fields of environmental management need to work together more effectively to identify high risk compounds, improve the reliability and coverage of future monitoring studies, and develop new mitigation measures.

This article discusses the separation of butanol from aqueous solutions and/or fermentation broth by adsorption. Butanol fermentation is also known as acetone butanol ethanol (ABE) or solvent fermentation. Adsorbents such as silicalite, resins (XAD-2, XAD-4, XAD-7, XAD-8, XAD-16), bone charcoal, activated charcoal, bonopore, and polyvinylpyridine have been studied. Use of silicalite appears to be the more attractive as it can be used to concentrate butanol from dilute solutions (5 to 790-810 g L(-1)) and results in complete desorption of butanol (or ABE). In addition, silicalite can be regenerated by heat treatment. The energy requirement for butanol recovery by adsorption-desorption processes has been calculated to be 1,948 kcal kg(-1) butanol as compared to 5,789 kcal kg(-1) butanol by steam stripping distillation. Other techniques such as gas stripping and pervaporation require 5,220 and 3,295 kcal kg(-1) butanol, respectively.

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We have used the yeast two-hybrid system to isolate cDNAs encoding proteins that specifically interact with the 42-aa ␤-amyloid peptide (A␤), a major constituent of senile plaques in Alzheimer's disease. The carboxy terminus of ␣ 2 -macroglobulin (␣2M), a proteinase inhibitor released in response to inf lammatory stimuli, was identified as a strong and specific interactor of A␤, utilizing this system. Direct evidence for this interaction was obtained by co-immunoprecipitation of ␣2M with A␤ from the yeast cell, and by formation of SDS-resistant A␤ complexes in polyacrylamide gels by using synthetic A␤ and purified ␣2M. The association of A␤ with ␣2M and various purified amyloid binding proteins was assessed by employing a method measuring proteinprotein interactions in liquid phase. The dissociation constant by this technique for the ␣2M-A␤ association using labeled purified proteins was measured (K d ‫؍‬ 350 nM). Electron microscopy showed that a 1:8 ratio of ␣2M to A␤ prevented fibril formation in solution; the same ratio to A␤ of another acute phase protein, ␣ 1 -antichymotrypsin, was not active in preventing fibril formation in vitro. These results were corroborated by data obtained from an in vitro aggregation assay employing Thiof lavine T. The interaction of ␣2M with A␤ suggests new pathway(s) for the clearance of the soluble amyloid peptide.Senile plaques in the brain and cerebral blood vessels of patients with Alzheimer's disease are composed primarily of the aggregated form of A␤ (1, 2). The A␤ peptide is derived post-translationally by proteolytic activity from a larger amyloid precursor protein (3-10). The mechanism for A␤ clearance or for its deposition is not known. Two proteinase inhibitors, ␣ 2 -macroglobulin (␣2M) and ␣ 1 -antichymotrypsin (␣1ACT), have been identified as being associated with senile plaques (11,12,13). ␣2M is capable of binding to and blocking the proteolytic activity of most proteinases before rapid clearance of these ␣2M -proteinase complexes by the low density lipoprotein receptor-related protein (LRP). Internalization and degradation of ␣1ACT-proteinase complexes are mediated by the serpin-enzyme complex receptor. Significantly increased levels of both ␣2M and ␣1ACT are often found in localized areas of inflammation (14,15,16). The full range of biological activities of ␣2M and ␣1ACT still remains to be defined.In an effort to identify proteins that interact in vivo with A␤ and therefore might play a role in its clearance or deposition, we screened a HeLa library using the yeast two-hybrid system (17-21). One of the proteins determined to have a strong and specific interaction with A␤ was ␣2M. To examine the possible role of this interaction in neurotoxic amyloid fibril formation, we investigated the following: (i) the in vivo binding of A␤ to ␣2M in the yeast cell; (ii) the in vitro binding affinity of A␤ to ␣2M compared with that of A␤ to other amyloid-binding proteins; and (iii) the effect of ␣2M, ␣1ACT, and apolipoprotein (apo) J on fibril formation. EXPERIMENTA...

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The present study investigated the cultivable mesophilic (37 degrees C) and thermophilic (60 degrees C) cellulose-degrading bacterial diversity in a weathered soil-like sample collected from the deep subsurface (1.5 km depth) of the Homestake gold mine in Lead, South Dakota, USA. Chemical characterization of the sample by X-ray fluorescence spectroscopy revealed a high amount of toxic heavy metals such as Cu, Cr, Pb, Ni, and Zn. Molecular community structures were determined by phylogenetic analysis of 16S rRNA gene sequences retrieved from enrichment cultures growing in presence of microcrystalline cellulose as the sole source of carbon. All phylotypes retrieved from enrichment cultures were affiliated to Firmicutes. Cellulose-degrading mesophilic and thermophilic pure cultures belonging to the genera Brevibacillus, Paenibacillus, Bacillus, and Geobacillus were isolated from enrichment cultures, and selected cultures were studied for enzyme activities. For a mesophilic isolate (DUSELG12), the optimum pH and temperature for carboxymethyl cellulase (CMCase) were 5.5 and 55 degrees C, while for a thermophilic isolate (DUSELR7) they were 5.0 and 75 degrees C, respectively. Furthermore, DUSELG12 retained about 40% CMCase activity after incubation at 60 degrees C for 8 h. Most remarkably, thermophilic isolate, DUSELR7 retained 26% CMCase activity at 60 degrees C up to a period of 300 h. Overall, the present work revealed the presence of different cellulose-degrading bacterial lineages in the unique deep subsurface environment of the mine. The results also have strong implications for biological conversion of cellulosic agricultural and forestry wastes to commodity chemicals including sugars.

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BackgroundReduced yields of ethanol due to bacterial contamination in fermentation cultures weaken the economics of biofuel production. Lactic acid bacteria are considered the most problematic, and surveys of commercial fuel ethanol facilities have found that species of Lactobacillus are predominant. Bacteriophage lytic enzymes are peptidoglycan hydrolases that can degrade the Gram positive cell wall when exposed externally and provide a novel source of antimicrobials that are highly refractory to resistance development.ResultsThe streptococcal phage LambdaSa2 (λSa2) endolysin demonstrated strong lytic activity towards 17 of 22 strains of lactobacilli, staphylococci or streptococci and maintained an optimal specific activity at pH 5.5 and in the presence of ≤ 5% ethanol (fermentation conditions) toward L. fermentum. Lactobacillus bacteriophage endolysins LysA, LysA2 and LysgaY showed exolytic activity towards 60% of the lactobacilli tested including four L. fermentum isolates from fuel ethanol fermentations. In turbidity reduction assays LysA was able to reduce optical density >75% for 50% of the sensitive strains and >50% for the remaining strains. LysA2 and LysgaY were only able to decrease cellular turbidity by <50%. Optimal specific activities were achieved for LysA, LysA2, and LysgaY at pH 5.5. The presence of ethanol (≤5%) did not reduce the lytic activity. Lysins were able to reduce both L. fermentum (BR0315-1) (λSa2 endolysin) and L. reuteri (B-14171) (LysA) contaminants in mock fermentations of corn fiber hydrolysates.ConclusionBacteriophage lytic enzymes are strong candidates for application as antimicrobials to control lactic acid bacterial contamination in fuel ethanol fermentations.