Pharmaceutically active compounds (PhACs) have been found in wastewater effluents and receiving waters around the world. As yet there are no jurisdictions that regulate their release, or their impact on receiving water ecosystem health. The issue is complex due to the number of PhACs that exist, the variability in their structure and function, the variability in removal during different wastewater treatment processes, the potential for formation of metabolites and transformation products, and a lack of information on the impacts due to their presence on receiving waters. Gemfibrozil is a lipid regulating drug that is commonly found in wastewater effluents and receiving waters. It has been shown to partially degrade during biological wastewater treatment processes and has also been shown to produce reaction products through reactions with free chlorine. This thesis investigated the removal and transformation of gemfibrozil through several different wastewater treatment processes, namely biological removal and chlorination. Reactions between gemfibrozil and free chlorine led to the identification of four reaction products. The structures of three of the four reaction products were elucidated. The kinetics of formation of these reaction products were then investigated at a range of pH values, and in two wastewater matrices. One reaction product, 4’-ClGem was shown to form under conditions relevant to wastewater treatment. The impacts of gemfibrozil and 4’-ClGem presence on the abundance of suspended and biofilm bacteria in a simulated receiving water experiment were evaluated. It was shown that changes in the water matrix had more of an impact on bacterial abundance than presence of gemfibrozil or 4’-ClGem. A bacterial dose-response experiment showed a negative response at 10 mg/L exposure to 4’-ClGem, which is orders of magnitude higher then what would be found in receiving waters. In order to prevent the formation of chlorinated reaction products, it is necessary to remove gemfibrozil prior to disinfection. Recirculating biofilters (RBS), a biological technology for onsite or small-scale wastewater treatment, were explored as a potential treatment process for gemfibrozil removal. Results indicate that RBFs show promise as a robust technology to remove greater than 50% of influent gemfibrozil.

The presented dissertation is a study focused on the characterization of sensory quality, especially the flavour of model samples of natural cheeses. Attention is aimed to the composition and content of volatile (sensory active) substances as important markers of flavour and free/bound fatty acids as their precursors. The headspace solid phase microextraction in conjunction with gas chromatography with mass spectrometry was used to determine volatiles. For the determination of fatty acids, the lipids were isolated from the sample with a solvent mixture of diethyl ether and petroleum ether, followed by esterification using a methanolic solution of boron trifluoride as a catalyst and final analysis by gas chromatography with flame ionization detection. The experimental part was divided into two experiments; in experiment I, Moravský bochník type cheeses (45 % fat in dry matter., 60 % dry matter) were analysed, in experiment II, Edam type cheeses (45 % fat in dry matter, 50 % dry matter). Model samples of cheeses were made at Tomas Bata University in Zlín. For all samples, a classical mesophilic culture containing Lactococcus spp. and Leuconostoc spp. was used, this was always supplemented with a suitable monoculture of thermophilic bacteria; in the case of Moravský bochník cultures of Streptococcus thermophilus and Lactobacillus helveticus and in the case of Edam cheeses Lactobacillus casei and Lactobacillus plantarum. The essence of both experiments was to assess the influence of the used microbial cultures on the above-mentioned parameters, at the same time their changes during the ripening of the cheeses were monitored. The results showed that the addition of thermophilic cultures, as well as the maturation process did not affect the number of fatty acids or volatiles, but significant differences were found in their content. The content of bound fatty acids decreased during cheese ripening due to ongoing lipolytic changes while increasing the content of free fatty acids and their subsequent degradation to volatile substances, which ultimately contribute to the taste and aroma of the cheese. Ketones and acids were the most quantitatively present in all samples. During maturation, contrary to expectations, the content of identified volatiles also decreased. The addition of the thermophilic cultures didn’t have a clear effect and varied depending on the maturation phase. In the first phase, although they showed more pronounced lipolytic activity, the subsequent metabolic processes - the breakdown of free fatty acids into volatile substances, compensated for these differences. These results confirm a significant share of the basic mesophilic culture in the formation of volatile substances, in particular the flavour of cheeses.

This work deals with monitoring of sensory active compounds during production of Edam cheeses, i.e. natural hard cheeses with low heat curd, and of processed cheeses, which were produced from Edam cheeses. Sensory active compounds contribute to overal flavour of cheese. They are volatile compounds, which include alcohols, aldehydes, ketones, fatty acids, esters, lactones, terpenes etc. These compounds were identified and quantified using SPME/GC/FID method in the model samples of Edam cheeses and processed cheeses, produced at Tomas Bata University in Zlin. In total 42 volatile compounds were identified, 6 aldehydes, 7 ketones, 15 alcohols, 6 esters and 8 acids. Differences in number of compounds identified, as well as in the contents of them, were found between samples. Effect of pasteurization on the contents and composition of the identified compounds was the most obvious in the samples of matured cheeses. In the samples of processed cheeses the effect of pasteurization was the most obvious in combination with prolonged heating during melting.

This thesis describes development and optimalization of method for identification of polyphenols compounds present in hops (Humulus lupulus L.) that have potential antimicrobial activity. Within extraction of compounds from hop, minced hop cones were applied in a growth medium, where compounds diffused into the medium and created an inhibition zone after inoculated with Streptococcus aureus. The method combining extraction with acetone a salting out using QuEChERS principles was optimized for extraction of compounds from solid growth medium. The analysis was carried out using LC/HR-MS with a quadrupole-orbitrap hybrid mass analyzer. The MS method was developed as a screening method with a subsequent fragmentation of compound of interest on the base of inclusion mass list. The compounds extracted from inhibition zone were identified either by searching against a database or their structures have been elucidated on the basis of their fragmentation spectra.

A crescente demanda dos consumidores por produtos seguros e com vida de prateleira estendida fez aumentar o interesse nas chamadas embalagens ativas. Estas podem interagir com o alimento, promovendo a melhoria de suas características, além da manutenção de sua segurança e qualidade. Dentre os compostos ativos comumente empregados para a formação deste tipo específico de embalagem, o sorbato de potássio e a nisina tem chamado a atenção, devido às suas propriedades antimicrobianas, sendo reconhecidos como conservantes seguros para alimentos por organizações como a Food and Agriculture Organization (FAO), World Health Organization (WHO) e Food and Drug Administration (FDA). Neste contexto, o presente trabalho teve como objetivo o desenvolvimento e a caracterização de filmes à base de quitosana como veículo dos agentes antimicrobianos sorbato de potássio (SP) e nisina (N). Os filmes foram produzidos pela técnica de casting, mantendo-se constante a concentração da quitosana em 2g/100g de solução filmogênica, e incorporando-se o SP e a N nas concentrações de 2,5, 5,0, 7,5 e 10,0 mg/g de quitosana. Os filmes foram caracterizados quanto à sua umidade, solubilidade em água, propriedades mecânicas (tensão na ruptura, elongação e módulo elástico), ângulo de contato, microscopia eletrônica de varredura (MEV), espectroscopia de infravermelho com transformada de Fourier (FTIR), e difusão dos compostos bioativos em meio aquoso. A umidade dos filmes não foi afetada pela adição dos compostos antimicrobianos em nenhuma das concentrações, variando entre aproximadamente 22 e 24%, e a solubilidade de todas as formulações foi completa, possivelmente devido ao alto grau de desacetilação da quitosana utilizada. Em relação às propriedades mecânicas, foi observada redução da tensão na ruptura e um forte aumento na elongação com o aumento da concentração tanto de SP quanto de N. Por outro lado, para o módulo elástico, foi constatado redução com o aumento da concentração de SP, diferente da N, onde não houve variação deste valor para as diferentes concentrações analisadas. A hidrofobicidade do filme aumentou com o aumento da concentração de ambos os compostos, verificada pelo aumento no ângulo de contato. As análises de MEV demonstraram que os filmes se apresentaram coesos, com estrutura homogênea e com ausência de regiões de descontinuidade, independente do agente antimicrobiano. Foi observado o aparecimento de um pico na região de 1650 nm, para os filmes adicionados de sorbato de potássio, indicando possível interação entre o grupo carboxila do sorbato de potássio, e o grupo amina da quitosana. Para as análises de difusão, o modelo proposto apresentou bom ajuste, principalmente aos adicionados de SP, apresentando uma difusão mais controlada com o tempo. Observou-se uma difusividade efetiva na ordem de 10-13m2/s sem diferença estatística entre as concentrações analisadas. Portanto, pode-se concluir que os filmes de quitosana adicionados dos agentes antimicrobianos sorbato de potássio e nisina têm um bom potencial na formação de embalagens ativas, difundindo em meio aquoso de maneira eficaz, além de conferir aos filmes melhorias em suas propriedades físico-químicas. / Increasing consumer demand for safe products and with extended shelf-life has increased the interest in active packaging. It is designed to interact with food, improving its characteristics, keeping the safety and quality maintenance. Among the active compounds commonly used to form this particular type of packaging, potassium sorbate and nisin has drawn attention due to its antimicrobial properties, being recognized as safe for food applications by the Food and Agriculture Organization (FAO), World Health Organization (WHO) and Food and Drug Administration (FDA). In this context, this work aimed at the development and characterization of chitosan-based films as a vehicle of the antimicrobial agents potassium sorbate (PS) and nisin (N). The films were produced by casting technique, keeping the concentration of chitosan constant in 2g/100g of filmogenic solution and incorporating the PS and N at the concentrations of 2.5, 5.0, 7.5 and 10.0 mg/g of chitosan. The films were characterized for their moisture content, water solubility, mechanical properties (tensile stress, elongation at break and young modulus), contact angle, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and diffusion of the bioactive compound in aqueous media. The moisture content of the films was not affected by the addition of antimicrobial compounds in any of the concentrations, ranging between approximately 22 and 24%, and the solubility of all formulations was complete, perhaps due to the high deacetylation degree of chitosan used. In the mechanical properties, it was observed a decrease in the tensile stress and a strong increase in elongation with increasing concentration of both PS and N. On the other hand, for the young modulus, it was observed a decrease with increasing concentrations of PS, different from N, which was not observed variations of this value for the different concentrations analyzed. The hydrophobicity of the film increased when increasing the concentration of both compounds, observed by an increase in the contact angle. The SEM analysis showed that the films was cohesive, with an homogeneous structure and with no discontinuity regions, independent of the agent used. It was observed the appearance of a peak in the wavelength 1650 nm, for the films with potassium sorbate, indicating possible interaction between the carboxyl group of potassium sorbate, and the amine group of chitosan. For diffusion analysis, the model showed good agreement, especially the PS formulations, showing a more controlled diffusion with time. Diffusion coefficient was observed in the order of 10-13 m2/s with no statistical difference between the analyzed concentrations. Therefore, it can be concluded that the chitosan films made with potassium sorbate and nisin has good potential to produce active packaging, releasing their compounds effectively, and also conferring an improvement in its physicochemical properties.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-06-22T19:03:02Z No. of bitstreams: 1 AldileneSilvaLima.pdf: 13164666 bytes, checksum: cd1c6e1b366f76a72539ecddec6062e4 (MD5) / Made available in DSpace on 2017-06-22T19:03:02Z (GMT). No. of bitstreams: 1 AldileneSilvaLima.pdf: 13164666 bytes, checksum: cd1c6e1b366f76a72539ecddec6062e4 (MD5) Previous issue date: 2014-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Rhipicephalus microplus is an ectoparasite of major economic importance to cattle. The control cattle tick has difficult by resistance of populations to synthetic acaricides. Plant bioactive molecules can be an alternative to control this ectoparasite. The aim of this study was to evaluate the repellent and acaricide effect of extracts and essential oils from plants on the cattle tick R. microplus. Hexane, ethyl ether, ethanolic, and methanolic extracts was obtained of P. tuberculatum fruits. After extraction, all of the extracts were dried. Essential oil from L. alba was obtained by hydrodistillation, all oil essential of Citrus ssp. were extracted by cold pressing fruits and all the identification of the major compounds of essential oils was performed by gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography flame ionization detector (GC-FID). Monoterpenes was obtained commercially. All the extracts was use larval packet tests and Adult immersion tests. Oil essential was used to repellency test. All extracts showed highest larvicidal activity against R. microplus. Hexane extract showed a CL50 of 0.04 mg/mL, CL50 ethyl ether of 0.08 mg/mL and ethanolic LC50 of 2.73 mg/mL. P. tuberculatum fruit extracts were also effective against engorged females R. microplus. Genotypes LA-13 and LA-57 of L. alba showed repellent activity against larvae of R. microplus more than 40 hours at concentration of 6.88 mg/cm². Monoterpenes showed lower repellent activity. Oil essenctial of Citrus aurantium var. dulcis showed repellent activity more than 30 hours at concentration of 6.88 mg/cm². Other essential oils tested showed a time of repellency lower 5 hours. Ours results reported than plants contains bioactive compounds with great potential acaricides, and they can be commercial products for the control of R. microplus. / O Rhipicephalus microplus é um ectoparasita de maior importância econômica à bovinocultura. O controle do carrapato bovino tem sido dificultado pela resistência de populações aos acaricidas sintéticos. Compostos bioativos de plantas podem ser uma alternativa para o controle deste ectoparasita. O objetivo deste trabalho foi avaliar o efeito repelente e carrapaticida de extratos e óleos essenciais de plantas sobre o carrapato bovino R. microplus. Extratos da planta Piper tuberculatum foram obtidos com hexano, éter etílico, etanólico e metanólico. Depois todos os extratos foram rotoevaporado. Os óleos essenciais de Lippia alba foram obtidos por hidrodestilação, os de Citrus ssp. por prensagem a frio dos frutos e todos os componentes dos óleos essenciais foram analisados por Cromatografia Gasosa acoplada a espectrometria de massa (CG-MS). Os monoterpenos utilizados foram obtidos comercialmente. Todos os extratos foram utilizados no teste de larvas e imersão de fêmeas Ingurgitadas. Os óleos essenciais foram utilizados no teste de repelência. Todos os extratos demonstraram uma alta atividade sobre larvas de R. microplus. O extrato Hexânico de frutos de P. tuberculatum apresentou uma CL50 de 0,04 mg/mL, seguido de éter etílico com CL50 de 0,08 mg/mL, etanólico com CL50 de 2,73 mg/mL. O extrato éter etílico de frutos de P. tuberculatum também demonstrou uma alta atividade sobre fêmeas Ingurgitadas. Os genótipos LA-13 e LA-57 de Lippia alba apresentaram uma alta atividade repelente sobre larvas de R. microplus por mais de 40 horas numa concentração de 6,88 mg/cm². Os monoterpenos apresentaram baixa atividade repelente. O óleo essencial de Citrus aurantium var. dulcis apresentou uma alta atividade repelente com mais de 30 horas de repelência na concentração de 6,88mg/cm². Os demais óleos testados apresentaram um tempo de repelência menor que 5 horas. Nossos resultados demonstraram que as plantas possuem compostos ativos com alto potencial acaricida, e que podem vir a serem utilizados em produtos de uso comercial para o controle do carrapato bovino.

A indústria do processamento de frutas gera um grande volume de resíduos. Entretanto, muitos destes resíduos podem apresentar elevado valor nutricional, ou ainda, apresentarem teores importantes de compostos ativos com atividades antioxidantes, podendo, em alguns casos serem superiores às concentrações encontradas na polpa da fruta. Entretanto, o descarte de tais resíduos pode provocar sérios problemas ambientais. Diversos estudos relatam que os resíduos agroindustriais provenientes do processamento (produção de sucos, polpas congeladas, extratos secos, etc) de frutas podem ser usados na produção de diversos produtos, tais como: produtos de panificação, ração animal, fertilizantes, produção de biogás, dentre outros. Por outro lado, ainda há poucos estudos e aplicações frente ao grande potencial apresentado por estes resíduos. Diversos estudos relatam que resíduos agroindustriais provenientes do processamento do camu-camu apresentam teores significativas de compostos ativos e elevado valor nutricional. Assim, o objetivo deste projeto foi produzir e caracterizar farinhas obtidas em diferentes temperaturas (50, 60 e 70°C) do resíduo do despolpamento do camu-camu (FRCC) e avaliar o potencial para aplicação das mesmas em cookies. O resíduo foi submetido a secagem em três diferentes temperaturas (50, 60 e 70°C) em estufa de circulação forçada de ar, trituradas em moinho de facas e a granulometria padronizada em 16 mesh. As farinhas obtidas, assim como o resíduo úmido do processamento do camu-camu foram caracterizados quanto: ao conteúdo de água, atividade de água, pH, cor, composição centesimal (proteína, fibras, lipídeos, cinzas e carboidratos), composição mineral (nitrogênio, fósforo, potássio, cálcio, magnésio, enxofre, boro, cobre, ferro, manganês e zinco), fenólicos totais, potencial antioxidante (métodos do DPPH•, FRAP e ORAC), carotenóides, taninos, vitamina C, capacidade de absorção de água e óleo, capacidade emulsificante e capacidade espumante. Após a caracterização, a farinha com potencial antioxidante superior e maior concentração de fenólicos totais, foi utilizada para a produção de cookies com as seguintes porcentagens de substituição da farinha de trigo: 5%(C-5FRCC), 10% (C-10FRCC), 15% (C-15FRCC) e 20% (C-20FRCC), além do controle (sem substituição).Por sua vez, os cookies foram avaliados em relação ao conteúdo de água, pH, cor, perda de água, altura, diâmetro, fator de espalhamento, volume específico, dureza, fenólicos totais e potencial antioxidante (métodos do DPPH•, FRAP e ORAC). Verificou-se, de um modo geral, que a temperatura de secagem afetou as propriedades das farinhas, sendo que as farinhas obtidas após secagem a 70°C (FRCC70) apresentou valores superiores de concentração de compostos ativos e potencial antioxidante, em relação às farinhas obtidas após secagem nas demais temperaturas. Desta forma, a FRCC70 utilizada na produção dos cookies. A substituição parcial da farinha de trigo pela FRCC70 provocou pequenas alterações nas características físicas (altura, diâmetro, fator de espalhamento, volume específico) dos cookies, principalmente para as porcentagens de substituição mais elevadas desta farinha. De um modo geral, os cookies com substituição pela FRCC apresentaram dureza superior. Verificou-se ainda que o aumento da concentração da FRCC70 nos cookies provocou aumento da concentração dos compostos fenólicos. Da mesma forma, verificou-se que o aumento da porcentagem de substituição da FRCC70 nos cookies aumentou o potencial antioxidante medido pelos métodos do FRAP e ORAC. Por outro lado, não verificou-se efeito do aumento da porcentagem de substituição no potencial antioxidante medido pelo método do DPPH• dos cookies. Assim, verificou-se que a farinha do resíduo do processamento do camu-camu mostrou potencial para aplicação em cookies por poder agregar valor nutricional, em função do aumento do potencial antioxidante e da concentração de fenólicos totais desses produtos. / Fruit processing industry generates a high volume of by-products. However, many of these byproducts may present high nutritional value, or they may present important concentrations of active compounds with antioxidant activities, and in some cases they could have higher concentrations than thosefound in the fruit pulp. However, the discard of such by-prodcuts can cause serious environmental problems. Several studies report that the agroindustrial by-products from fruit process (production of juices, frozen pulp, dried extracts, etc.) can be used in the production of several products, such as: bakery products, animal feed, fertilizers, biogas production, among others. On the other hand, there are still few studies and applications in view of the great potential presented by these by-products. Several studies reported that agroindustrial by-products from camu-camu processing have significant concentrations of active compounds and high nutritional value. Thus, the aim of this project was to produce and characterize flours obtained at different temperatures (50, 60 and 70 ° C) of the camu-camu pulp by-product (FRCC) and to evaluate the potential for application of the same in cookies. By-product was dried in three different temperatures (50, 60 and 70 ° C) in a forced air circulation oven, milled with a knife mill and the standard granulometry in 16 mesh. Flours and the wet by-product were evaluated in relation to water content, water activity, pH, color, centesimal composition (protein, fiber, lipids, ashes and carbohydrates), mineral composition (nitrogen, phosphate, potassium, calcium, magnesium, sulfur, boron, copper, iron, manganese and zinc), total phenolics, antioxidant potential (DPPH•, FRAP and ORAC methods), carotenoids, tannins, vitamin C, water absorption capacity and oil, emulsifying capacity and foaming capacity. After the characterization, the flour with higher antioxidant potential and higher total phenolic concentration was used to produce cookies with the following percentages of wheat flour substitution: 5% (C-5FRCC), 10% (C-10FRCC), 15% (C-15FRCC) and 20% (C-20FRCC), in addition to the control (without substitution). Cookies were evaluated in relation towater content, pH, color, water loss, height, diameter, spreading factor, specific volume, hardness, total phenolics and antioxidant potential (DPPH•, FRAP and ORAC methods). It was generally found that the drying temperature affected the properties of the flour. The flour obtained after drying at 70 ° C (FRCC70) showed higher concentration of active compounds and antioxidant potential in relation to the flour obtained after drying in other temperatures. In this way, the FRCC70 used in the production of cookies. The partial replacement of wheat flour by FRCC70 caused small changes in the physical characteristics (height, diameter, spreading factor and specific volume) of the cookies, mainly for the higher substitution percentages of this flour. In general, cookies with FRCC70 substitution showed higher hardness. It was also verified that the increase of FRCC70 concentration in cookies caused an increase in the concentration of phenolic compounds, likewise, in the antioxidant potential measured by the FRAP and ORAC methods. On the other hand, no effect was observed in the antioxidant potential measured by the DPPH• method. Thus, it can be concluded that the flour of the camu-camu processing byproducts showed potential for application in cookies because it can add nutritional value, due to the increase of the antioxidant potential and the total phenolic concentration of these products.

<p>Large amounts of human pharmaceutical products are consumed worldwide. Many drugs and their metabolites, referred to as pharmaceutically active compounds (PhACs), are not fully metabolized prior to household discharge resulting in their common occurrence in wastewater treatment plants (WWTPs). In most instances, WWTPs present the first treatment opportunity for removing PhACs and preventing significant environmental exposure. Because most municipal WWTPs rely on the microbial component of the activated sludge process, there is a need to estimate the influence of PhACs in wastewater influent on the activated sludge microbial communities and the treatment performance of WWTPs. The objective of this dissertation was to determine the impact of selected PhACs (i.e., ketoprofen, naproxen, clofibric acid, carbamazepine and gemfibrozil) on activated sludge microorganisms and key individual microbial species in domestic wastewater treatment. Analyses were performed in batch reactors initially and then in laboratory-scale sequencing batch reactors (SBR) which mimic WWTP operations. Ammonia oxidizing bacteria (AOB) were selected as indicator organisms because of their importance in wastewater treatment and demonstrated sensitiveness to toxic compounds. </p><p>The batch experiments results suggested that microbial growth inhibition was correlated to organic loadings. In the presence of 0.2% (v/v) ethanol, significant inhibition, ranging from 34 to 43%, was observed for all PhACs other than clofibric acid. </p><p>Nitrification inhibition studies using Nitrosomonas europaea, a model AOB strain showed that ketoprofen, naproxen, carbamazepine and gemfibrozil inhibited nitrite production. The corresponding maximum nitrification inhibition rates were 25, 29, 22 and 26%, respectively. Inhibition was shown to increase with PhAC concentration for concentrations greater than 0.1 µM. Results from membrane integrity tests suggest that the inhibition may be due to the disturbance of the cell membrane by PhACs and such inhibition was shown to be irreversible. </p><p>Even though PhACs were shown to inhibit the nitrification rate in pure culture studies, the performance of SBRs exposed to individual PhACs was not adversely affected neither in terms of COD nor ammonia removal. Microbial fingerprinting for both total bacteria and AOB confirmed that no significant shifts occurred when microbial communities were exposed to PhACs. However, some PhACs introduced in binary mixture were found to both inhibit the nitrification of N. europaea as well as the performance of SBRs. The mixture composed of 0.5 &#956;M ketoprofen and 0.5 &#956;M naproxen showed significant inhibition (25%) on the nitrite production of N. europaea although neither 0.5 &#956;M ketoprofen nor 0.5 &#956;M naproxen had significant effect when presented alone. Similarly, both COD and ammonia removal were significantly impacted by binary mixtures of PhACs. These results suggest that mixture effects can play an important role in an overall treatment's nitrification potential and this phenomenon should be further investigated.</p> / Dissertation

Interactions are all around us, and as humans we may use words and gestures to communicate our intentions. At the micro level of fungi, communications are replaced by chemical signals and structure. These interactions fall into three distinctive categories: synergistic, where organisms help each other, as is the case with ectomycorrhizal fungi and tree roots, deadlock, or combat, where organisms fight for or defend a resource. When it comes to fungi-tree interactions, the fungi group of basidiomycetes fall into the latter category. At the onset of fungal infection, a living tree defends itself by producing resinous substances such as terpenes. These compounds are frequently found in hydrodistilled turpentine, which makes turpentine a prime source of antifungal compounds. A D-optimal design of fractionated turpentine together with gas chromatography (GC) coupled to a mass spectrometer was employed to find the most biologically active constituent of turpentine. Growth rate of Coniophora puteana was used to assess the efficacy of the mixed fractions. The partial least squares projection model had an excellent predictive power (R2 = 0.988, Q2 = 0.825) and validity. A putative sesquiterpene was identified as the most active compound for inhibiting fungal growth. The model was corroborated by an external validation assay employing preparative GC. After the death of a tree, fungi are no longer hindered by secondary metabolites from the tree. Instead, other interspecies interactions and intraspecies interactions, such as fungi-fungi interactions, occur. We found that when the white-rot fungus Heterobasidion parviporum and brown-rot fungus Gloeophyllum sepiarium interact with each other, amino acids are used to a higher extent. Amino acids may be used to produce antifungal compounds to hinder the other species from growing. Lysine in particular was utilized to a greater extent during interaction. Glutamine was the only amino acid that increased in concentration. Glutamine might be exuded or converted by enzymes from already existing glutamic acid. Dry weights suggest that the fungi were in a deadlock and that nutrient limitation might be a determining factor. It seemed that H. parviporum was favoured by a decrease in pH while the opposite pattern may be true for G. sepiarium.

A crescente demanda dos consumidores por produtos seguros e com vida de prateleira estendida fez aumentar o interesse nas chamadas embalagens ativas. Estas podem interagir com o alimento, promovendo a melhoria de suas características, além da manutenção de sua segurança e qualidade. Dentre os compostos ativos comumente empregados para a formação deste tipo específico de embalagem, o sorbato de potássio e a nisina tem chamado a atenção, devido às suas propriedades antimicrobianas, sendo reconhecidos como conservantes seguros para alimentos por organizações como a Food and Agriculture Organization (FAO), World Health Organization (WHO) e Food and Drug Administration (FDA). Neste contexto, o presente trabalho teve como objetivo o desenvolvimento e a caracterização de filmes à base de quitosana como veículo dos agentes antimicrobianos sorbato de potássio (SP) e nisina (N). Os filmes foram produzidos pela técnica de casting, mantendo-se constante a concentração da quitosana em 2g/100g de solução filmogênica, e incorporando-se o SP e a N nas concentrações de 2,5, 5,0, 7,5 e 10,0 mg/g de quitosana. Os filmes foram caracterizados quanto à sua umidade, solubilidade em água, propriedades mecânicas (tensão na ruptura, elongação e módulo elástico), ângulo de contato, microscopia eletrônica de varredura (MEV), espectroscopia de infravermelho com transformada de Fourier (FTIR), e difusão dos compostos bioativos em meio aquoso. A umidade dos filmes não foi afetada pela adição dos compostos antimicrobianos em nenhuma das concentrações, variando entre aproximadamente 22 e 24%, e a solubilidade de todas as formulações foi completa, possivelmente devido ao alto grau de desacetilação da quitosana utilizada. Em relação às propriedades mecânicas, foi observada redução da tensão na ruptura e um forte aumento na elongação com o aumento da concentração tanto de SP quanto de N. Por outro lado, para o módulo elástico, foi constatado redução com o aumento da concentração de SP, diferente da N, onde não houve variação deste valor para as diferentes concentrações analisadas. A hidrofobicidade do filme aumentou com o aumento da concentração de ambos os compostos, verificada pelo aumento no ângulo de contato. As análises de MEV demonstraram que os filmes se apresentaram coesos, com estrutura homogênea e com ausência de regiões de descontinuidade, independente do agente antimicrobiano. Foi observado o aparecimento de um pico na região de 1650 nm, para os filmes adicionados de sorbato de potássio, indicando possível interação entre o grupo carboxila do sorbato de potássio, e o grupo amina da quitosana. Para as análises de difusão, o modelo proposto apresentou bom ajuste, principalmente aos adicionados de SP, apresentando uma difusão mais controlada com o tempo. Observou-se uma difusividade efetiva na ordem de 10-13m2/s sem diferença estatística entre as concentrações analisadas. Portanto, pode-se concluir que os filmes de quitosana adicionados dos agentes antimicrobianos sorbato de potássio e nisina têm um bom potencial na formação de embalagens ativas, difundindo em meio aquoso de maneira eficaz, além de conferir aos filmes melhorias em suas propriedades físico-químicas. / Increasing consumer demand for safe products and with extended shelf-life has increased the interest in active packaging. It is designed to interact with food, improving its characteristics, keeping the safety and quality maintenance. Among the active compounds commonly used to form this particular type of packaging, potassium sorbate and nisin has drawn attention due to its antimicrobial properties, being recognized as safe for food applications by the Food and Agriculture Organization (FAO), World Health Organization (WHO) and Food and Drug Administration (FDA). In this context, this work aimed at the development and characterization of chitosan-based films as a vehicle of the antimicrobial agents potassium sorbate (PS) and nisin (N). The films were produced by casting technique, keeping the concentration of chitosan constant in 2g/100g of filmogenic solution and incorporating the PS and N at the concentrations of 2.5, 5.0, 7.5 and 10.0 mg/g of chitosan. The films were characterized for their moisture content, water solubility, mechanical properties (tensile stress, elongation at break and young modulus), contact angle, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and diffusion of the bioactive compound in aqueous media. The moisture content of the films was not affected by the addition of antimicrobial compounds in any of the concentrations, ranging between approximately 22 and 24%, and the solubility of all formulations was complete, perhaps due to the high deacetylation degree of chitosan used. In the mechanical properties, it was observed a decrease in the tensile stress and a strong increase in elongation with increasing concentration of both PS and N. On the other hand, for the young modulus, it was observed a decrease with increasing concentrations of PS, different from N, which was not observed variations of this value for the different concentrations analyzed. The hydrophobicity of the film increased when increasing the concentration of both compounds, observed by an increase in the contact angle. The SEM analysis showed that the films was cohesive, with an homogeneous structure and with no discontinuity regions, independent of the agent used. It was observed the appearance of a peak in the wavelength 1650 nm, for the films with potassium sorbate, indicating possible interaction between the carboxyl group of potassium sorbate, and the amine group of chitosan. For diffusion analysis, the model showed good agreement, especially the PS formulations, showing a more controlled diffusion with time. Diffusion coefficient was observed in the order of 10-13 m2/s with no statistical difference between the analyzed concentrations. Therefore, it can be concluded that the chitosan films made with potassium sorbate and nisin has good potential to produce active packaging, releasing their compounds effectively, and also conferring an improvement in its physicochemical properties.