1,720,977 research outputs found
Candida aquaetextoris sp. nov., a new species of yeast occurring in sludge from a textile industry wastewater treatment plant in Tuscany, Italy
No full textWe describe Candida aquaetextoris, a new yeast species isolated from sludge that accumulates at the main wastewater treatment facility which processes discharges from textile factories located in the Prato metropolitan district, northern Tuscany, Italy. This yeast degrades 4.(1-nonyl)phenol, a toxic intermediate originating from the microbial attack of nonylphenol polyethoxylates, which are nonionic surfactants largely used in leather and textile industries. In the investigation we employed conventional and molecular taxonomy techniques to compare the new isolate to strains of physiologically similar species, such as Candida maltosa and Candida tropicalis, as well as strains of quite phenotypically different species, such as Candida haemulonii. The results demonstrate that the yeast which we identified represents a separate taxon
Co-composting for managing effluent from thermophilic anaerobic digestion of municipal solid waste
No full textAnaerobic effluent from thermophilic digestion (55°C) of organic fraction of municipal solid waste (OFMSW) was ultimately treated through a co‐composting process. OFMSW sorted by an industrial plant was used as bulking agent mixed to the digested effluent in the co‐composting experiment. Compost detoxification of the anaerobic effluent was carried out in a static windrow aerated by blowing air in it. The bio‐oxidative post‐treatment technology adopted allowed the anaerobic effluent mixed with the OFMSW to overcome phytotoxicity and to reach maturity for a possible use as organic amendant in agriculture. Short term composting (5 weeks) proved also to act efficiently in drying and hygienizing the initial waste biomass
Antimutagenic and Antioxidant Activity of a Selected Lectin-free Common Bean (Phaseolus vulgaris L.) in Two Cell-based Models
No full textLegumes and particularly beans are a key food of Mediterranean diet representing an important source of proteins, fiber, some minerals and vitamins and bioactive compounds. We evaluated the antioxidant and anti-mutagenic effects of a new fermented powder of a selected lectin-free and phaseolamin-enriched variety of common bean (Phaseolus vulgaris L.), named Lady Joy. Lady Joy lysate (Lys LJ) was studied in human erythrocytes and in Saccharomyces cerevisiae yeast cells. The antioxidant and anti-hemolytic properties of Lys LJ, studied in an ex vivo erythrocytes system using the cellular antioxidant assay (CAA-RBC) and the hemolysis test, evidenced a dose-dependent antioxidant activity as well as a significant hemolysis inhibition. Besides, results evidenced that Lys LJ treatment significantly decreased the intracellular ROS concentration and mutagenesis induced by hydrogen peroxide in S. cerevisiae D7 strain. In conclusion, Lys LJ showed both an antimutagenic effect in yeast and a strong scavenging activity in yeast and human cells
Biodegradation of 4-(1-nonyl)phenol by axenic cultures of the yeast Candida aquaetextoris: Identification of microbial breakdown products and proposal of a possible metabolic pathway
No full textCandida aquaetextoris, a yeast recently described for its ability to use 4-(1-nonyl)phenol (pNP) as the sole carbon and energy source in aerobic conditions, has been studied in order to determine the degradation products deriving from the growth on such a compound which is of environmental concern because of its proved toxicity to several organisms. Two main metabolites, namely trans-4-hydroxy-cinnamic acid and 4-hydroxy-acetophenone (4-acetylphenol), have been identified through either TLC and NMR spectrometry analyses of liquid substrate from cultures of C. aquaetextoris grown on pNP, with 4-acetylphenol that accumulates without any further degradation. These findings suggest that C. aquaetextoris might metabolise pNP via terminal oxidation of the alkyl chain, followed by a β-oxidation pathway. On the basis of this evidence, a novel metabolic route for the microbial degradation of 4-(1-nonyl)phenol, at least in certain yeasts, is proposed
Biodegradazione di tesioattivi non ionici: isolamento in coltura pura di microorganismi attivi
No full textSono riportati i risultati di uno studio relativo all’isolamento in coltura axenica e la caratterizzazione funzionale di ceppi microbici capaci di degradare i tensioattivi non-ionici polietossilati che rappresentano un serio fattore di inquinamento data la tossicità e la refrattarietà al decadimento durante i trattamenti depurativi delle acque reflue di molti comparti industriali quali quello tessile, quello conciario, quello della carta e molti altri ancora
Bacterial attack of non-ionic aromatic surfactants: comparison of degradative capabilities of new isolates from nonylphenol polyethoxylate polluted wastewaters
No full textNonylphenol polyethoxylates (NPEOs) are largely used in many different industrial applications. In 1987 estimated production of NPEOs in Europe was 150,000 tons, with 25,000 tons only produced in Italy. They represent a group of compounds which are of environmental concern because of their toxicity to biological systems. Furthermore, NPEOs and their intermediates tend to accumulate in sewage sludge during wastewater depuration or possibly in sediments once treated waters are discharged into rivers and sea. Primary degradation of NPEOs, that also means the loss of surfactant properties, easily occurs in aerobic conditions as a consequence of the progressive loss of ethylene oxide units. On the other hand, complete mineralization appears to proceed very slowly. Anyway scarce information is available about microorganisms which possibly carry out biodegradation of these compounds. The present paper reports results concerning the isolation and characterization of three different Gram negative bacteria from nonylphenol polyethoxylate contaminated sludge, that can individually attack NPEOs in axenic cultures effecting primary degradation
Procedure per l'ottimizzazione degli interventi nei progetti di bonifica biologica di suoli contaminati
No full textSono esposti i criteri che devono governare l’adozione di misure tese alla esaltazione delle reazioni microbiche finalizzate alla biodegradazione/bitrasformazione degli inquinanti presenti in un determinato contesto ambientale
Effect of compost-derived humic acids on vegetable biomass production and microbial growth within a plant (Cichorium intybus)-soil system: A comparative study
No full textThe responses of chicory plants to amendments with natural and synthetic surface active substances, represented by either potassium humates from compost stabilised green waste or Tween 80, are reported from a pot trial. Results are evaluated in terms of plant biomass production and behaviour of soil microbial populations following different treatments. Amendments with humic acids stimulated vegetative growth of chicory. They also caused significative variations in the numbers of bacterial heterotrophs and autotrophic nitrifiers in the soil. The study suggests that the mechanism through which humic acids affect both plant and soil microbes may chiefly involve enhancement of cell membrane permeability to nutrients
Biodegradation of dibenzothiophene by a bacterial isolate of Burkholderia sp., strain DBT1
No full textBurkholderia sp. DBT1 is a bacterial strain formerly isolated from the wastewater dicharge pipeline of an oil refinery located in Tuscany, Italy. It is cable of biodegrading dibenzothiophene (DBT) in liquid culture through the “Kodama pathway” within three days of incubation
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