The Occurrence of Trihalomethane Compounds in Salt Lake City and Ogden, Utah, Drinking Water Supplies

A purge and trap, gas chromatography system was developed to analyze for trihalomethane (THMs) compounds at the ppb (parts per billion) level in drinking water. Monthly influent and effluent samples were taken from three Weber Basin Water Conservancy Distrcit treatment plants, three Salt Lake City water treatmetn platns, and one Slat Lake Metropolitan water treatment plant. In addition tap water samples were taken at various business and residential locations in Salt Lake City, Utah, and Ogen, Utah. All samples were analyzed for trihalomethanes and total organic carbon (TOC). In addition to monthly sampling, a comparison of the production of THMs during post and prechlorination of water at the Parleys Water Treatment Plant in Salt Lake City was conducted. moving th epoint of chlorination within the treatment plant did not appear to reudce trihalomethane levels in the finished product. Highest trihalomethane levels (84 ug/1) occurred in the summer months with the lowest levels (\u3c1 ug/1) recorded in the winter. The chemical form of the THMs varied from chloroform to the more brominated hydrocarbon from late winter through spring

Bioremediace persistentních aromatických polutantů

The remediation of persistent chlorinated aromatic compounds has become a priority of great relevance due to the teratogenic, carcinogenic and endocrine-disrupting properties of these xenobiotics. The use of biological methodologies for the clean-up of contaminated sites, collectively referred to as "bioremediation", has been gaining an increasing interest in recent years because it represents an effective, cost-competitive and environmentally friendly alternative to the physico-chemical and thermal treatments. In this respect, "white rot" fungi, an ecological subgroup of filamentous fungi, display features that make them excellent candidates to design an effective remediation technology ("mycoremediation"). In spite of this, fungi have not been widely exploited for their metabolic capabilities and the mechanism by which they are able to degrade the aforementioned pollutants has not been fully elucidated yet. Within this frame, the present Ph.D thesis was aimed at: i) assessing the efficiency of different mycoremediation strategies for the clean-up of a polychlorinated biphenyl (PCBs)-contaminated soil; ii) understanding the fungal degradation pathways of polychlorinated biphenyls and their major metabolites, namely chlorobenzoic acids (CBAs) and hydroxylated polychlorinated biphenyls (OH-PCBs). i)...Remediace persistentních chlorovaných aromatických sloučenin se stala prioritou vzhledem k teratogenním, karcinogenním a endokrinním účinkům těchto xenobiotik. V současné době si získává při sanacích znečištěných lokalit stále větší pozornost použití biologických remediačních technologií, souhrnně označovaných jako bioremediace. Představují efektivní, cenově konkurenceschopnou alternativu šetrnou k životnímu prostředí ve srovnání s fyzikálně-chemickými dekontaminačními postupy. Jako vhodný kandidát pro vytvoření remediační technologie se jeví skupina ligninolytických basidiomycetních hub tzv. houby bílé hniloby (mykoremediace). Doposud však nebyly pro své metabolické schopnosti široce využívány a mechanismus, jakým jsou schopny degradovat výše zmíněné polutanty, není rovněž plně prozkoumán. Tato disertační práce byla zaměřena na: i) zhodnocení účinnosti různých mykoremediačních strategií při odstraňování polychlorovaných bifenylů (PCB) z kontaminované půdy, ii) porozumění mechanismu specifických houbových degradačních drah PCB a jejich hlavních metabolitů (CBA, chlorbenzoové kyseliny a OH-PCB, hydroxylované polychlorované bifenyly). i) K vyhodnocení technické proveditelnosti vybraných remediačních strategií byla použita kombinace chemických, toxikologických a molekulárně-biologických technologií....Institute for Environmental StudiesÚstav pro životní prostředíFaculty of SciencePřírodovědecká fakult

Green degradation of mycotoxins by biotechnological application of enzymes from Pleurotus spp

Le micotossine sono metaboliti secondari tossici, prodotti da funghi filamentosi che appartengono principalmente ai generi Aspergillus, Penicillium, Fusarium e Alternaria. Sono comuni contaminanti alimentari di cereali, frutta, semi e spezie, prodotti a seguito di contaminazione fungina. La contaminazione da micotossine ha un impatto importante sulla salute mondiale e sulla sua economia. Alcune di esse sono classificate come sostanze cangerogene umane (aflatossine delle serie B e G) o possibili cancerogene umane (aflatossina M1, AFM1, fumonisina B1, FB1 e ocratossina A, OTA) dall’Agenzia Internazionale per la Ricerca sul Cancro (IARC). Inoltre, esplicano una azione tossica, sia acuta che cronica, su umani e animali. A causa della contaminazione da micotossine, milioni di dollari vengono persi ogni anno a causa di commodities invendute, problemi di salute e diminuzione della produttività degli animali e per la messa a punto di sistemi complessi e integrati di lotta e gestione di queste problematiche. Le strategie preventive non sono completamente efficaci e richiedono di essere implementate con nuove strategie di riduzione che agiscano nel post raccolta e che siano in grado di ridurre o di rimuovere le micotossine dai materiali contaminati. Lo scopo di questa tesi è stato quello di valutare e studiare la capacità delle laccasi di ridurre la contaminazione di micotossine, sia in vitro che in materiali contaminati, attraverso un approccio non invasivo sugli alimenti e sull’ambiente. Inoltre, fino a otto diversi mediatori redox sono stati utilizzati insieme alle laccasi nel cosiddetto Sistema Laccasi Mediatore (LMS) per massimizzare la degradazione delle micotossine. Per raggiungere questo scopo, l’attività di due diverse laccasi purificate, la Lac2 da Pleurotus pulmonarius e la ricombinante Ery4 da P. eryngii sono state testate contro le maggiori classi di micotossine. La Lac2 è stata identificata e valutata per la degradazione in vitro delle aflatossine, mentre la Ery4 è stata testata contro AFB1, AFM1, FB1, OTA, deossinivalenolo (DON), zearalenone (ZEN) e tossina T-2. iv Lo screening preliminare ha rivelato che l’inclusione di un mediatore redox nel mix di reazione è necessario per raggiungere un alto livello di degradazione con entrambi gli enzimi. Tuttavia, l’ LMS è risultato non completamente efficace per la degradazione dell’OTA e non efficace per la degradazione del DON. Attraverso l’uso di uno specifico LMS è stata ottenuta anche la degradazione simultanea di due diverse coppie di tossine, AFB1/ZEN e FB1/ tossina T-2. In aggiunta, il trattamento con LMS è stato utilizzato con successo in matrici artificialmente e naturalmente contaminate, latte e farina di mais, per la degradazione di AFM1 e ZEN, rispettivamente. Nonostante le grandi potenzialità mostrate da entrambi gli enzimi nel campo del biorisanamento, le laccasi restano dei biocatalizzatori versatili che possono essere utilizzati in una grande varietà di processi. L’applicazione dell’LMS è stato studiato in dettaglio nel latte per valutarne l’effetto sulle proteine del latte e la possibilità di produrre una cagliata con proprietà tecnologiche e nutrizionali migliorate. I risultati presentati in questa tesi pongono le basi per lo sviluppo di un metodo di biotrasformazione basato su un approccio enzimatico che apre nuove prospettive per l’utilizzo di un biocatalizzatore versatile e green, come la laccasi, nel campo della sicurezza e della qualità delle derrate alimentari contaminate da micotossine.Mycotoxins are toxic secondary metabolites produced by filamentous fungi mainly belonging to Aspergillus, Penicillium, Fusarium and Alternaria genera. They can be found as common contaminants of cereals, fruits, seeds and spices as a result of fungal spoilage. Mycotoxin contamination is an significant health and economic concern worldwide. Some of them were recognized by the International Agency of Research on Cancer (IARC) as carcinogenic (aflatoxin of the B and G series), possible carcinogenic (aflatoxin M1, AFM1; fumonisin B1, FB1; ochratoxin A, OTA) to humans. Moreover, they exert both acute and chronic toxic effects towards humans and animals. Because of mycotoxin contamination, billions of dollars are lost every year due to unsold commodities, decrease of animal health and productivity or to sustain a complex and integrated mycotoxin management system. Prevention strategies are not completely effective and require the implementation of novel post-harvest methods, able to mitigate or remove mycotoxins from contaminated materials. The aim of this thesis was to evaluate and study the capability of laccase enzymes to reduce mycotoxin contamination both in vitro and in contaminated materials through an environmental friendly and mild approach. In addition up to eight different redox mediators were used within the laccase mediator system (LMS) to maximize mycotoxin degradation. Within this purpose, the activity of two different purified LCs, native Lac2 from Pleurotus pulmonarius and the recombinant Ery4 from P. eryngii, was tested towards the main classes of mycotoxins. Lac2 was identified and evaluated for the in vitro degradation of aflatoxins, while Ery4 was tested towards AFB1, AFM1, FB1, OTA, deoxynivalenol (DON), zearalenone (ZEN) and T-2 toxin. The preliminary screening revealed that the inclusion of a toxin - specific redox mediator is required to achieve high levels of degradation with both enzymes. However, the use of the LMS resulted ineffective for DON and not efficient for OTA. i

AN EXTENSIVE REVIEW ON SUNSCREEN AND SUNTAN PREPARATIONS

The sunscreen industry is achieving remarkable worldwide prominence by responding to the growing need for skin protection with fast-paced innovation. Increased consumer awareness of the harmful effects of sunlight has fueled the demand for improved photoprotection. The need for broad-spectrum protection from both ultraviolet (UV) A and UV B rays has inspired scientists worldwide to research new cosmetic formulations and delivery systems. More effective sunscreen actives, emollients and novel cosmetic and functional ingredients have been regularly added to the formulator’s repertoire. Creativity in innovation has been hindered only by regulatory agencies and patent restrictions worldwide. Familiarity with the current restrictive regulations and patent law infringements has become integral to any research effort attempting to provide improved protection to individuals affected by the sun’s damaging effects. The increasing incidence of skin cancers and photodamaging effects caused by UV radiation has increased the use of sun screening agents which have shown beneficial effects in reducing the symptoms and reoccurrence of these problems. Unlike the situation in Europe where sunscreen ingredients are considered under cosmetics guidelines, the food and drug administration (FDA) is required to define sunscreens as drugs since they are advertised to prevent sunburn and, more recently, the risk of skin cancer. In the USA, the FDA has been regulating this industry since August 25, 1978, with the publication of the advance notice of proposed rulemaking. Sunscreens are considered drugs and cosmetics and therefore must be governed by the FDA-over-the-counter monograph. With the variety of sunscreen agents used in cosmetic and UV protection products, Australia, Canada, and the European Union (EU) have also developed regulatory protocols on safe sunscreen product use. Unlike the USA, though, Australia has approved 34 active sunscreen ingredients and the EU has approved 28 of these ingredients. Current FDA regulations allow labeling of sunscreen products to a maximum of 30þ, despite the many products currently available with numbers as high as 100. From a cosmetic formulation point of view, increasing the sun protection factor number in a product is governed by simple chemical principles

Advancing Knowledge on Cyanobacterial Blooms in Freshwaters

Cyanobacterial blooms are a water quality problem that is widely acknowledged to have detrimental ecological and economic effects in drinking and recreational water supplies and fisheries. There is increasing evidence that cyanobacterial blooms have increased globally and are likely to expand in water resources as a result of climate change. Of most concern are cyanotoxins, along with the mechanisms that induce their release and determine their fate in the aquatic environment. These secondary metabolites pose a potential hazard to human health and agricultural and aquaculture products that are intended for animal and human consumption; therefore, strict and reliable control of cyanotoxins is crucial for assessing risk. In this direction, a deeper understanding of the mechanisms that determine cyanobacterial bloom structure and toxin production has become the target of management practices. This Special Issue, entitled “Advancing Knowledge on Cyanobacterial Blooms in Freshwaters”, aims to bring together recent multi- and interdisciplinary research, from the field to the laboratory and back again, driven by working hypotheses based on any aspect of mitigating cyanobacterial blooms, from ecological theory to applied research