Waste lipids to energy: how to optimize methane production from long-chain fatty acids (LCFA)

The position of high-rate anaerobic technology (HR-AnWT) in the wastewater treatment and bioenergy market can be enhanced if the range of suitable substrates is expanded. Analyzing existing technologies, applications and problems, it is clear that, until now, wastewaters with high lipids content are not effectively treated by HR-AnWT. Nevertheless, waste lipids are ideal potential substrates for biogas production, since theoretically more methane can be produced, when compared with proteins or carbohydrates. In this minireview, the classical problems of lipids methanization in anaerobic processes are discussed and new concepts to enhance lipids degradation are presented. Reactors operation, feeding strategies and prospects of technological developments for wastewater treatment are discussed. Long-chain fatty acids (LCFA) degradation is accomplished by syntrophic communities of anaerobic bacteria and methanogenic archaea. For optimal performance these syntrophic communities need to be clustered in compact aggregates, which is often difficult to achieve with wastewaters that contain fats and lipids. Driving the methane production from lipids/LCFA at industrial scale without risk of overloading and inhibition is still a challenge that has the potential for filling a gap in the existing processes and technologies for biological methane production associated to waste and wastewater treatment.Fundação para a Ciência e a Tecnologia (FCT) - project FAT-METHANE (POCTI/CTA/46328/2002), grants PRAXIS XXI/BD/20326/99, SFRH/BPD/14591/2003, SFRH/BD/24256/2005Instituto Nacional da Propriedade Industrial (INPI)Netherlands Science FoundationLettinga Associates Foundatio

Proportion of circulating Gc (vitamin D-binding protein) in complexed form: Relation to clinical outcome in fulminant hepatic necrosis

Alterations in circulating levels of vitamin D-binding protein (Gc) and the percentage of Gc in complexed form were further studied in normal subjects and in patients with fulminant hepatic necrosis in relation to clinical outcome. Levels of Gc were markedly reduced in all 7 patients studied, particularly in nonsurvivors. The percentage of Gc in complexed form was generally <10% in normal subjects. However, complexes were increased in all patients, and the percentage correlated strongly with clinical outcome, being 22% ± 7.3% in survivors and 72% ± 7.5% in those who died (p < 0.001). These results provide further evidence that Gc plays an important role in complexing and clearance of cellular actin released during tissue necrosis

Monitoring substratum hygiene using an everyday complex organic soil: the human fingerprint

Human fingerprint residue is an example of a specific and complex organic-material/microorganism soil which is often present in a variety of environments that are required to be hygienic. When applied onto surfaces a fingerprint may affect cleanability and influence bacterial retention, alter topography and in some cases, may even compromise the aesthetic qualities of the material. One of the most common modes of cross contamination in hygienic environments is via the human hand but this soil/microorganism matrix is rarely studied in controlled conditions. Modifications were made to published sweat and sebum standard formulations to allow a gram positive organism (Staphylococcus aureus) and a gram negative representative (Escherichia coli) to survive in a synthetic fingerprint soil for subsequent hygienic assessment of a range of surfaces. Alongside this, a method has been developed for depositing a range of organic soils in specific quantities and arrangements (e.g., the synthetic fingerprint soil in a fingerprint pattern) onto a range of substrata to allow surfaces to be more accurately assessed for cleanability