Search results for "bacteria."
showing 10 items of 4757 documents
C1 Inhibitor-C1¯sComplexes Are Internalized and Degraded by the Low Density Lipoprotein Receptor-related Protein
1997
Like other serpin-enzyme complexes (SECs), proteinase-complexed C1 inhibitor (C1-INH) is rapidly cleared from the circulation and thought to be a neutrophil chemoattractant, suggesting that complex formation causes structural rearrangements exposing a domain which is recognized by specific cell surface receptors. However, the cellular receptor(s) responsible for the catabolism and potential mediation of chemotaxis by C1-INH-protease complexes remained obscure. To determine whether the SEC receptor mediates the binding and potential chemotaxis of C1-INH·C1s, we performed binding assays with HepG2 cells, neutrophils, and monocytes, and the results show that C1-INH·C1s neither bind to these ce…
Increased sulfate availability in saline water promotes hydrogen sulfide production in fish organic waste
2020
The risk of hydrogen sulfide (H2S) production can be a challenge in marine land-based recirculating aquaculture systems (RAS). Hydrogen sulfide is a toxic gas that can cause massive fish mortality even at low concentrations, and in addition, serious odour problems in the surroundings. It is a bacterial by-product originating from the degradation of organic matter in sulfur-rich waters such as marine waters. In order to hinder H2S production in marine land-based RAS, more information on the H2S production conditions and the associated microbiology is needed. In this study, the production of H2S from rainbow trout (Oncorhynchus mykiss) organic waste was examined using a novel H2S measurement …
Host-guest interactions for extracting antibiotics with a γ-cyclodextrin poly(glycidyl-co-ethylene dimethacrylate) hybrid sorbent
2021
Abstract A procedure for the solid-phase extraction of antibiotics (enoxacin, ofloxacin, norfloxacin, ciprofloxacin, and sparfloxacin) in water has been developed. The sorbent used is based on a poly(glycidyl-co-ethylene dimethacrylate) network, whose previously modified surface has been functionalized with γ-cyclodextrin through a click-chemistry reaction. The architecture of the material has been characterized by thermogravimetric analysis, N2 adsorption-desorption, Raman spectroscopy, confocal microscopy, and scanning electron microscopy, showing good capability to be used as a filler for extraction cartridges. The optimization of the extraction methodology shows good intra-day and inter…
Molecular/chemical ecology in sponges. Evidence for an adaptive antibacterial response in Suberites domuncola
2004
Sponges (Porifera) represent the evolutionary oldest metazoan phylum still extant today. They have developed a complex Bauplan, based on the existence of structural and regulatory molecules; many of these have been cloned and analyzed in the past years. The demosponge Suberites domuncula has been used as a suitable model to demonstrate that these animals not only possess an adaptive immune response on the level of cytokines, but also, as pointed out here, on the level of synthesis of bioactive alkyl-lipid derivatives. From specimens of S. domuncula the two lyso-PAF (platelet-activating factor) compounds, 1-O-hexadecyl-sn-glycero-3-phosphocholine and 1-O-octadecyl-sn-glycero-3-phosphocholine…
Exploring the limits of anaerobic biodegradability of urban wastewater by AnMBR technology
2018
[EN] Anaerobic membrane bioreactors (AnMBRs) can achieve maximum energy recovery from urban wastewater (UWW) by converting influent COD into methane. The aim of this study was to assess the anaerobic biodegradability limits of urban wastewater with AnMBR technology by studying the possible degradation of the organic matter considered as non-biodegradable as observed in aerobic membrane bioreactors operated at very high sludge retention times. For this, the results obtained in an AnMBR pilot plant operated at very high SRT (140 days) treating sulfate-rich urban wastewater were compared with those previously obtained with the system operating at lower SRT (29 to 70 days). At 140 days SRT the …
Evaluation of the enzymatic activity of selected bacterial strains
2007
Evaluation of the enzymatic activity of selected bacterial strains In these studies we attempted to evaluate the lipolytic, proteolytic and cellulolytic activity of bacterial strains isolated from water and the bottom sediments of Turawa Lake. The following bacterial genera prevailed among the isolated strains: Bacillus, Pseudomonas, Enterobacter, Cellulomonas and Cytophaga. The lipolytic activity was determined using a titrimetric method, the proteolytic activity — using a modified Anson method, and the cellulolytic activity - on the basis of mass decrement of a cellulose disk after 14 days of bacterial culture. The cultures were maintained at 28°C, pH 7.0 with the following substrates: ol…
Distinct and diverse anaerobic bacterial communities in boreal lakes dominated by candidate division OD1
2012
Lakes have a central role in the carbon cycle of the boreal landscape. These systems typically stratify in summer and their hypolimnetic microbial communities influence burial of biogenic organic matter in sediments. The composition of bacterial communities in these suboxic habitats was studied by pyrosequencing of 16S rRNA amplicons from five lakes with variable dissolved organic carbon (DOC) concentrations. Bacterioplankton communities in the hypolimnetic waters were clearly different from the surface layer with candidate division OD1, Chlorobi and Bacteroidetes as dominant community members. Several operational taxonomic units (OTUs) affiliated with candidate division OD1 were abundant a…
Discriminative features of type I and type III secreted proteins from Gram-negative bacteria
2006
AbstractThe amino acid composition of sequences and structural attributes (α-helices, β-sheets) of C-and N-terminal fragments (50 amino acids) were compared to annotated (SWISS-PROT/ TrEMBL) type I (20 sequences) and type III (22 sequences) secreted proteins of Gram-negative bacteria.The discriminant analysis together with the stepwise forward and backward selection of variables revealed the frequencies of the residues Arg, Glu, Gly, Ile, Met, Pro, Ser, Tyr, Val as a set of strong (1-P < 0.001) predictor variables to discriminate between the sequences of type I and type III secreted proteins with a cross-validated accuracy of 98.6–100 %. The internal and external validity of discriminant…
UJI AKTIVITAS ANTIBAKTERI DAN SKRINING FITOKIMIA EKSTRAK HEKSANA, ETIL ASETAT DAN METANOL TUMBUHAN SURUHAN (Peperomia pellucida L. Kunth)
2020
Antibacterial activity test and screening of phytochemical of extract hexane, ethyl acetate and methanol have been carried out. The extraction of the P.pellucida plants was carried out by the maceration method in stages based on the polarity of the solvent. Analysis of chemical compounds done with phytochemical screening test. Based on the identification of chemical compounds by phytochemical screening, hexane and ethyl acetate extract has been detected only in the presence of flavonoid compounds with moderate categories. Methanol extract contains high-grade alkaloids and moderate flavonoid and tannin compounds. Antibacterial test using disffusion methods suggest that ethyl acetate and me…
The Role of Lectins in Finfish: A Review
2019
The immune system of vertebrates involves both innate and acquired immune responses. The innate immunity is more generalized with robust response whereas the other has a highly specific response to infectious pathogens. Because of the lack of specialized lymphatic organs, innate immunity is an important mode of defense in fishes. The less specific innate immune system acts mainly through complement pathway which depends on pattern-based recognition of “self” and “non-self” targets by host lectins and associated proteins. This ultimately results in the clearance of target cells. Lectins are glycoproteins which possess at least one carbohydrate recognition domain (CRD) that specifically and r…