Search results for "DIGESTION"
showing 10 items of 357 documents
Evaluation of potential biogas production in Sicily
2012
The aim of the present work is to predict the Sicilian potential biogas production, using the below unmarketable raw materials. The statistical data about OFMSW, the number of animals bred on medium and large farms and the amounts of by-products of food processing industries have been evaluated, in order to compute the potential biogas production and energy in the nine provinces of Sicily. In Sicily (Italy) 5.05 million inhabitants (2012), living in nine provinces, could produce 0.8 million tons of the Organic Fraction of Municipal Solid Waste (OFMSW) per year. At present only 0.07 million tons (3.17 % ca. of MSW) are actually treated (2010). This fraction would be one of the raw materials …
A new method to valued efficiency of enzyme blends for pancreas tissue digestion
2009
One of the best successful examples of cell therapy is represented by islet transplantation since 1990. However islet isolation methods are not completely standardized yet. More than half of isolation procedures failed to isolate adequate islets for transplantation, due to variable pancreas conditions and to unpredictable enzymatic blend efficiency. Enzymes used for pancreas digestion include collagenases and neutral proteases: their composition and activity are largely variable between different batches. We set up a new in vitro method to better in vitro characterize enzymatic blend before its use in human pancreas. In our experimental approach human immortalized cells (ECV-304) or human is…
Background element content in the lichen Pseudevernia furfuracea: a comparative analysis of digestion methods
2019
In bioaccumulation studies, the interpretation of pollutant contents in the target biomonitor has to be performed by assessing a deviation from an unaltered reference condition. A common strategy consists in the comparison with background element content (BEC) values, often built up by uncritically merging methodologically heterogeneous data. In this respect, the acid digestion of samples was identified as a major step affecting BEC data. Here, the analytical outcomes of two acid mixtures were compared on a set of matched paired samples of the lichen Pseudevernia furfuracea, a widely used biomonitor for which BEC values based on partial digestion were previously provided. The standard refer…
Development of an aerobic digestion model for the assessment of greenhouse gases production (AeDMG1): Calibration and validation
2015
The increasing interest in greenhouse gas emissions from WWTPs has been leading to new tools for their designing and managing. The activated sludge models have been modified in order to consider on – site emissions from nitrification and denitrification, in particular. The biological nitrogen removal processes have been mainly assessing due to nitrous oxide (N2O) production as intermediate. The IPCC suggests that N2O contributes to climate change because it has a global warming potential 298-fold stronger than carbon dioxide. Even if the mathematical modelling is wide regarding the activated sludge models for greenhouse gases, a model for aerobic digestion is still not available. In this pa…
Determination of ultratrace bismuth in milk samples by atomic fluorescence spectrometry.
2003
Abstract A sensitive procedure was developed for determination of bismuth (Bi) in milk samples by hydride generation atomic fluorescence spectrometry (HG–AFS) after microwave-assisted sample digestion with HNO3 and H2O2. The method provides a sensitivity of 1832 fluorescence units (ng/mL) with a detection limit of 0.01 ng/mL, which corresponds to 20 pg absolute limit of detection, equivalent to 0.50 ng/g in the original sample. Application of the methodology to cow milk samples from the Spanish market showed the presence of Bi at a concentration of 11.8–28.8 ng/g, which compared well with data obtained after dry ashing of samples and with data obtained by inductively coupled plasma–mass spe…
Improvement of the thermophilic anaerobic digestion and hygienisation of waste activated sludge by synergistic pretreatment
2019
Hybrid disintegration of waste activated sludge (WAS) before the thermophilic anaerobic stabilization of WAS contributes to the intensification of organic compounds decomposition and increases the effectiveness of the anaerobic stabilization process compared to the fermentation of raw WAS. This article investigates the influence of a chemical-thermal pretreatment procedure with the use of NaOH and freezing by the dry ice on WAS. We found that the hybrid pretreatment of WAS causes higher concentration of released organics in the liquid phase (represented here as a change in soluble chemical oxygen demand - SCOD value) in comparison to these disintegration techniques used separately. The use …
From grass to gas: microbiome dynamics of grass biomass acidification under mesophilic and thermophilic temperatures
2017
Background Separating acidification and methanogenic steps in anaerobic digestion processes can help to optimize the process and contribute to producing valuable sub-products such as methane, hydrogen and organic acids. However, the full potential of this technology has not been fully explored yet. To assess the underlying fermentation process in more detail, a combination of high-throughput sequencing and proteomics on the acidification step of plant material (grass) at both mesophilic and thermophilic temperatures (37 and 55 °C, respectively) was applied for the first time. Results High-strength liquor from acidified grass biomass exhibited a low biodiversity, which differed greatly depen…
Anaerobic solubilisation of nitrogen from municipal solid waste (MSW)
2003
This paper reviews anaerobic solubilisation of nitrogen municipal solid waste (MSW) and the effect of current waste management practises on nitrogen release. The production and use of synthetically fixed nitrogen fertiliser in food production has more than doubled the flow of excessive nitrogenous material into the community and hence into the waste disposal system. This imbalance in the global nitrogen cycle has led to uncontrolled nitrogen emissions into the atmosphere and water systems. The nitrogen content of MSW is up to4.0% of total solids (TS) and the proteins in MSW have a lower rate of degradation than cellulose. The proteins are hydrolysed through multiple stages into amino acids …
Biological effects of short-chain fatty acids in nonruminant mammals.
1993
propionate, volatile fatty acids (VFAs), cholesterol, cell prolifera tion, human gastric lipase
Diet shapes the gut microbiota of the omnivorous cockroach Blattella germanica
2015
The gut microbiota of insects contributes positively to the physiology of its host mainly by participating in food digestion, protecting against pathogens, or provisioning vitamins or amino acids, but the dynamics of this complex ecosystem is not well understood so far. In this study, we have characterized the gut microbiota of the omnivorous cockroach Blattella germanica by pyrosequencing the hypervariable regions V1-V3 of the 16S rRNA gene of the whole bacterial community. Three diets differing in the protein content (0, 24 and 50%) were tested at two time points in lab-reared individuals. In addition, the gut microbiota of wild adult cockroaches was also analyzed. In contrast to the high…