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At least 793 records · Page 44Linked to original sources
PubMed2003

Fatty acids of lipid fractions in extracellular polymeric substances of activated sludge flocs.

Phospholipid (PL), glycolipid (GL), and neutral lipid (NL) FA, and the lipopolysaccharide 2- and 3-hydroxy (LPS 2-OH and 3-OH) FA of activated sludges and extracted extracellular polymeric substances (EPS) were determined on samples collected from two wastewater treatment plants. EPS extracted from sludges by means of sonication and cation exchange contained proteins (43.4%), humic-like substances (11.5%), nucleic acids (10.9%), carbohydrates (9.9%), and lipid-bound FA (1.8%). The lipids associated with EPS were composed of GL, PL, NL, and LPS acids in proportions of 61, 21, 16, and 2%, respectively. The profiles of lipid-bound FA in activated sludges and EPS were similar (around 85 separate FA were identified). The FA signatures observed can be attributed to the likely presence of yeasts, fungi, sulfate-reducing bacteria, gram-positive and gram-negative bacteria, and, in lesser quantities, mycobacteria. Comparison of data from the dates of sampling (January and September) showed that there were more unsaturated PLFA in the EPS extracted from the activated sludges sampled in January. This observation could be partly related to microorganism adaptation to temperature variations. The comparison between two wastewater treatment plants showed that the FA profiles were similar, although differences in microbial community structure were also seen. Most of the FA in sludges had an even number of carbons.

Extracellular Fluid↗
PubMed2005

Identification of chemical substances in industrial wastes and their pyrolytic decomposition products.

In order to quantify the sources of chemical pollutants in the leachate from reclaimed wastes, chemical substances in 11 different types of industrial wastes were identified. Their elution behaviors were also investigated. Alkanes (5.3-890 ng g(-1)), benzenes (8.1-110 ng g(-1)), polyaromatic hydrocarbons (PAHs) (3.2-560 ng g(-1)), alcohols, steroids, phenol (7.1 ng g(-1)), ketones, furans (190-210 ng g(-1)), phthalates (8.9-560 ng g(-1)), benzoquinones, dibenzothiophene (190 ng g(-1)), benthiocarb (4.2 ng g(-1)), sulfur, nitrile compounds, amino compounds, amido compounds, pyridines, quinolines (1.8-15 ng g(-1)), isoquinolines, carbazoles, acridines, chlordenes (1.5-1.6 ng g(-1)) and nonachlors (1.1-1.6 ng g(-1)) were detected in 9 types of industrial wastes. The chemical substances detected in waste at the highest concentrations were alkanes, PAHs and phthalates. Water supply sludge, dust and brick garbage contained many kinds of chemical substances. The elution behaviors of specific chemical substances, COD and nutrients varied by characteristic and production process of each waste. Over 100 different compounds were detected in pyrolysis products including carbohydrate, carotynoid, amino acids, proteins, humic acids, lignin and combustion products.

Dust↗
PubMed1993

Influence of Tołpa Peat Preparation on haemostasis in rats.

The influence of Tołpa Peat Preparation (TPP) on certain parameters of haemostasis was studied. The present results indicate that TPP (100, 200 and 300 mg/kg p.o.) had no influence on the bleeding time, clotting time, thrombin time, prothrombin time, kaolin-kephalin time, euglobulin lysis time, the concentration of fibrinogen, the platelet count and ADP-induced platelet aggregation. No changes in animals after long-term treatment with TPP (100 mg/kg for two weeks) were found either. In in vitro studies TPP given in concentrations 10(-5), 10(-4), 10(-3) and 10(-2) g/cm3 was used and certain changes of the studied parameters, probably caused by the presence of high salt content in this substance, were observed.

Amino Acids↗
PubMedDate not supplied

Cellulase activity, degradation of cellulose and lignin and humus formation by cellulolytic fungi.

Cellulase activity and degradation of cellulose and lignin in wheat straw and formation of humus during degradation by Botryotrichum sp., Masoniella sp., Paecilomyces fusisporus, Sclerotium sp. and Trichurus spiralis was studied. All the cultures exhibited carboxy-methyl-cellulase activity, but cellulase activity on cellulose powder, filter paper and cotton was shown only by Masoniella sp., P. fusisporus and Sclerotium sp. when grown on cellulose powder in submerged culture conditions. However, when grown on wheat straw in solid culture all fungi exhibited FPD activity. All except Masoniella sp. degraded both cellulose and lignin efficiently as compared to cellulose. There was formation of humus like substances during growth of fungi on wheat straw.

Carboxymethylcellulose Sodium↗
PubMed2001

Evaluation of gel filtration resins for the removal of PCR-inhibitory substances from soils and sediments.

A variety of gel filtration resins (Sephadex G200 and G150; Sepharose 6B, 4B and 2B; Bio-Gel P100, P200; and Toyopearl HW 55, HW 65, and HW 75) were evaluated for their efficacy in removing PCR-inhibitory substances from feedlot soil DNA crude extracts using gravity-flow disposable columns. Sepharose resins demonstrated the best properties for DNA purification when compared to other gel filtration resins, and Sepharose 2B was the most efficient purification resin based upon flow rate and the elution of DNA and humic acids from the columns. A method for purifying large solution volumes of DNA extract economically was also developed using low-cost disposable Disposaflex columns. Crude DNA extracts of cattle feedlot soil and aquifer sediment impacted by animal and human wastes were easily purified using the Disposaflex column method regardless of whether a gentle chemical lysis or a bead mill homogenization DNA extraction method was employed.

Animals↗
PubMed2025

New insights into soil amendment: Impact of humic acid on typical antibiotic resistance in agricultural soil.

Humic acid (HA) addition can improve agricultural soil, but little is known about how it affects the soil resistome. In this study, we used selective agar plate combined with quantitative PCR (qPCR) and 16S rRNA gene sequencing to investigate how HA influences antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs) in soil contaminated with erythromycin and kanamycin. 0.1 % HA reduced the abundance of culturable erythromycin-resistant bacteria (ERB), while promoting the growth of kanamycin-resistant bacteria (KRB). Lysinibacillus and Paenibacillus were the dominant genera in ERB and KRB, respectively, governing the changes in their abundances. At this concentration, the Lysinibacillus abundance in ERB decreased from 96.74 % to 70.57 %. Meanwhile, that of Paenibacillus in KRB increased from 33.40 % to 77.44 %. The copy number of ermF decreased after HA addition, while that of ermB increased. Furthermore, 0.1 % HA significantly reduced the copy number and relative abundance of aadA1 and aac(6')-Ib (aka aacA4)-03 in the soil. Changes in these two types of ARB and ARGs were primarily driven by shifts in the microbial community structure. Soil physicochemical properties, particularly increased organic matter (OM), altered the absolute abundance of ermB. Meanwhile, changes in intI1 abundance determined the risk associated with aadA1 and aac(6')-Ib (aka aacA4)-03. These findings emphasize the dual role of HA in the dissemination of antibiotic resistance in agricultural soils and highlight the necessity of considering dose-dependent effects when applying HA as a soil amendment.

Soil Microbiology↗
PubMed1999

Bioassays for risk assessment of coal conversion products.

Traditional as well as biotechnological processing of coal leads to complex mixtures of products. Besides chemical and physical characterization, which provides the information for product application, there is a need for bioassays to monitor properties that are probably toxic, mutagenic or cancerogenic. Investigations carried out focused on the selection, adaptation and validation of bioassays for the sensitive estimation of toxic effects. Organisms like bacteria, Daphnia magna and Scenedesmus subspicatus, representing different complexities in the biosphere, were selected as test systems for ecotoxicological and mutagenicity studies. The results obtained indicate that bioassays are, in principle, suitable tools for characterization and evaluation of coal-derived substances and bioconversion products. Using coal products, coal-relevant model compounds and bioconversion products, data for risk assessment are presented.

Animals↗
PubMed2000

The influence of fulvic and ulmic acids from peat, on the spontaneous contractile activity of smooth muscles.

The aim of the presented studies was to evaluate which classes of compounds of peat ingredients could be responsible for the partial agonistic effect of aqueous peat extract on the alpha2 adreno and D2 dopamine receptors of smooth muscles, which we have reported from former investigations. Based on the different solubility of peat ingredients, water-soluble components of fulvic and ulmic acids were separated according to the pH-value and chemical structure of the solvent. The biological activity of these acids was examined in peat baths using smooth muscle fibers of guinea pig stomach. The results demonstrate that the water-soluble components of fulvic and ulmic acids have a partially agonistic effect on the alpha2 adreno and D2 dopamine receptors, but at the same time quite different effects in terms of their influence on the spontaneous contractile activity (SCA) of smooth muscles have to be noted. From these investigations, we can conclude that aqueous peat extract and the water-soluble components of fulvic acid exhibit similar partial agonistic effects on the alpha2 adreno and D2 dopamine receptors. Therefore it is likely that the mentioned effects of the peat extract derive from the fulvic- and ulmic acids only. The water-soluble component of ulmic acid also showed partial agonistic effects on alpha2 adreno and D2 dopamine receptors. In this case, another substance group is involved, which has a faster blocking effect on these receptors, but was barely soluble in water at a normal pH-value (pH 7).

Animals↗