ABSTRACT
This study evaluated the feasibility of obtaining methane in anaerobic digestion (AD) from the waste products generated by the processing of fruit and vegetables. During the first phase (0-55 d) of the AD using sludge from fruit and vegetable processing, an average value of 244±88 L kg(-1) dry matter d(-1)of biogas production was obtained, and methane content reached 65% of the biogas. Co-digestion with chopped fresh artichoke wastes in a second phase (55-71 d) enhanced biogas production, and resulted in an average value of 354±68 L kg(-1) dry matter d(-1), with higher methane content (more than 70%). The archaeal community involved in methane production was studied using the ANAEROCHIP microarray and real-time PCR. Results indicated that species of Methanosaeta and Methanosarcina were important during the AD process. Methanosarcina numbers increased after the addition of chopped fresh artichoke, while Methanosaeta numbers decreased.
Subject(s)
Archaea/metabolism , Cynara scolymus/chemistry , Fruit/chemistry , Refuse Disposal/methods , Sewage/microbiology , Vegetables/chemistry , Waste Products/analysis , Ammonia/analysis , Anaerobiosis , Archaea/genetics , Biodegradation, Environmental , Biofuels , Fatty Acids, Volatile/analysis , Gene Dosage/genetics , Methane , Oligonucleotide Array Sequence Analysis , Principal Component Analysis , RNA, Ribosomal, 16S/genetics , VolatilizationABSTRACT
The effects of Tween 20 on the desorption of proteins from polyethylene and polyurethane were studied, using single protein solutions of the human proteins fibrinogen (Fb), immunoglobulin G (IgG), serum albumin (HSA), high density lipoproteins (HDL), and plasma. The surfactant may partly or even completely desorb the proteins, depending on the type of polymer and protein. About 40% of adsorbed HSA and 80% of adsorbed HDL from the corresponding single protein solutions were desorbed by Tween 20 from polyethylene, whereas Tween 20 had a small effect on the desorption of adsorbed Fb and IgG under the same conditions. However, the desorption of Fb and IgG by Tween 20 was much higher in the case of a diluted plasma solution compared to a pure protein solution. These findings may be explained by the differences of the interaction strengths between polymers and the adsorbed proteins. The displacement of HSA from polyethylene by Tween 20 occurred in the first few minutes and did not increase in time. It was also observed that preadsorbed Tween 20 was able to prevent in a large extent the adsorption of HSA onto polyethylene. Thus, the effect of Tween 20 on the desorption of protein is due to either the displacement of protein or prevention of protein adsorption onto the surfaces.
Subject(s)
Polyethylenes/chemistry , Polysorbates/pharmacology , Polyurethanes/chemistry , Proteins/chemistry , Surface-Active Agents/pharmacology , Adsorption/drug effects , Binding, Competitive , Blood Proteins/chemistry , Blood Proteins/metabolism , Fibrinogen/chemistry , Fibrinogen/metabolism , Humans , Immunoenzyme Techniques , Immunoglobulin G/chemistry , Immunoglobulin G/metabolism , Lipoproteins, HDL/chemistry , Lipoproteins, HDL/metabolism , Polyethylenes/metabolism , Polysorbates/metabolism , Polyurethanes/metabolism , Serum Albumin/chemistry , Serum Albumin/metabolism , Surface-Active Agents/metabolismABSTRACT
Plasma and CSF levels of beta-Endorphin (beta-End) were measured by radioimmunoassay in three groups of human subjects. The first group consisted of healthy adults, and only plasma beta-End was determined. The second group consisted of patients showing non-painful neurological diseases. The third group consisted of patients suffering from acute pain due to herniated intervertebral discs. In the last two groups, beta-End levels were measured in plasma and CSF. The results showed that plasma levels of beta-End were similar in the first two groups of patients. In contrast, patients with acute pain showed significantly increased levels of beta-End in plasma. CSF levels of beta-End did not show significant differences among the groups. The results suggest that the increase in plasma levels of beta-End was a consequence of the stress produced by acute pain.
