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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Development of new synthetic methodologies and the synthesis of natural products

Sheth, Ritesh B. January 2010 (has links)
Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisor: Douglass F. Taber, Dept. of Chemistry & Biochemistry. Includes bibliographical references.
42

Characterization of the actinomycetes from the rhizosphere of a desert shrub, big sagebrush (Artemisia tridentata), focusing on their production of novel antifungal antibiotics and bioactive secondary metabolites /

Sandanasamy, Antony Jose Basil. January 1900 (has links)
Thesis (Ph. D.)--University of Idaho, 2005. / Also available online in PDF format. Abstract. "May 2005." Includes bibliographical references.
43

Effects of cationic antimicrobial peptides on Candida and Saccharomyces species /

Harris, Mark R. January 2010 (has links)
Thesis (Ph.D.) - University of St Andrews, April 2010.
44

Efeito da nistatina, fluconazol e do extrato etanolico de propolis de Apis mellifera sobre propriedades de superficie de resina acrilica / Effect of nystatin, fluconazole and ethanolic extract of Apis mellifera propolis on acrylic resin surface

Silva, Wander José da, 1980- 30 September 2005 (has links)
Orientadores: Altair Antoninha Del Bel Cury, Pedro Luiz Rosalen / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-05T09:42:20Z (GMT). No. of bitstreams: 1 Silva_WanderJoseda_M.pdf: 3982460 bytes, checksum: cc52755a091670127495a82d48ac39c9 (MD5) Previous issue date: 2005 / Resumo: Na candidose, ou estomatite induzida por prótese, a Candida albicans atua como o patógeno mais importante e mais virulento. A terapêutica indicada no tratamento são os agentes antifúngicos (AA) como Fluconazol (FLU) e Nistatina (NYS) e mais recentemente tem sido indicado soluções a base de própolis. Entretanto, a literatura é escassa sobre os efeitos destes agentes nos materiais utilizados para confecção de bases de próteses. O objetivo deste estudo foi verificar a influência de NYS, FLU, e gel orobase (GO) de própolis sobre a superfície de resinas acrílicas durante período de 14 dias. Água destilada e GO manipulado sem princípio ativo foram utilizadas como grupos controle. Espécimes (3,0 x 2,5 x 0,5 cm) foram fabricados a partir de moldes de cera, com resina acrílica polimerizada em banho de água (Jet Clássico, grupos 1 a 5) ou com energia de microondas (OndaCryl, grupos 6 a 10), ambas processadas de acordo com as instruções dos fabricantes. Após a confecção, os espécimes receberam acabamento e polimento e a rugosidade superficial (RS), ângulo de contato (AC), energia livre de superfície (ELS) e dureza de superfície (DS) foram mensuradas. Os tratamentos de superfície foram feitos com os AA e grupos controles e os espécimes foram escovados com dentifrício e escova macia 3 vezes ao dia durante os 14 dias. Os meios de imersão foram substituídos diariamente. Novas mensurações para as variáveis foram executadas em 3, 7, 10 e 14 dias de exposição. Os compostos dos AA que poderiam ser incorporados à resina acrílica foram mensurados por cromatografia líquida. Os resultados mostraram que a RS aumentou para ambas as resinas acrílicas, mas não diferiram entre si (p>0,05); os grupos G2 e G7, contendo propolis mostraram valores maiores e estatisticamente diferente dos demais agentes nos tempos de T7, T10 e T14 (p<0,05). Também com o passar do tempo os grupos G1, G3, G4 e G8 mostraram valores de rugosidade aumentada e significantemente diferente dos demais tempos (p<0,05, teste de Tukey). Nas análises de cromatografia não foi detectada a presença de FLU ou NYS, assim como não foi detectada diferença entre as resinas acrílicas (p>0,05, teste de Tukey) quanto a compostos do GO. A microscopia eletrônica de varredura mostrou as alterações sobre a superfície dos espécimes após o tratamento. Dentro dos limites deste estudo, é possível concluir que os agentes antifúngicos podem interferir com propriedades da superfície de resina acrílica que são associadas a adesão de Candida sp / Abstract: The high prevalence of candidosis in denture wearers, and its association to Candida spp. as principal pathogen is well established. Besides, there are many studies about candidosis etiology, predisposing factors and its treatment using antifungal agents such as Fluconazole (FLU) and Nystatin (NYS). However, little work has been performed to explore the effects of these antifungal agents on acrylic resin surface. The aim of this study was to verify the influence of NYS, FLU, and propolis orobase gel over surface acrylic resins. Distillate water and orobase gel without any active component were used as control groups. Specimens (3.0 x 2.5 x 0.5 cm) were fabricated from wax moulds using heat cured (HC = Clássico; groups 1 to 5) or microwave cured (MW = Onda Cry; groups 6 to 10) acrylics resin, both processed according to manufacturers¿ instructions. After polymerized the specimens were polished and had their surface roughness (SR), contact angle (CA), surface free energy (SFE) and hardness (HD) measured. The surface treatments were done with antifungal agents and controls. The specimens had their surface toothbrushed 3 times a day during the 14 days of exposure to antifungal agents. The antifungal agents¿ solutions and gels were replaced daily. Measurements to all variables were performed in days 3, 7, 10 and 14. Components from antifungal agents that could be incorporated to acrylic resin measured with liquid chromatography. The results showed that SR increased for both acrylic resins and the treatment with propolis showed higher values and statistically different from the others (p<0.05). No statistical difference (Tukey test, p>0.05) was found regarding CA and SFE. No presence of FLU or NYS were detected in chromatography and no difference (p<0.05) between acrylic resins were detect to orobase gels detection. Scanning electronic microscopy evaluation showed surface alterations after treatment. Within the limits of this study, it is possible to conclude that antifungal agents are able to interfere with the surface properties of acrylic resins that are associated to Candida spp. adhesion / Mestrado / Protese Dental / Mestre em Clínica Odontológica
45

The antifungal activity of an aqueous Tulbaghia violacea plant extract against Aspergillus flavus

Belewa, Xoliswa Vuyokazi January 2015 (has links)
Phytochemical analysis of both HEA1 and the crude plant extract showed the presence of phenolics, tannins and saponins. Saponins were the predominant secondary metabolites and were mostly abundant in the plant extract and to a lesser extent in the active compound. Steroidal saponins, tannins and phenolics were also detected in the plant extract, but only the phenolics were detected in the active compound. The results of the phytochemical analysis showed that those compounds that were not present in the active compound could be removed from the crude extract during the TLC purification process. Investigation on the mechanism of action of the crude plant extract on the sterol production by A. flavus showed that the plant extract affected ergosterol biosynthesis by causing an accumulation of oxidosqualene in the ergosterol biosynthetic pathway resulting in a decline in ergosterol production. An oscillatory response in lanosterol production was observed in the presence of the plant extract, which may be an adaptation mechanism of A. flavus to unfavourable conditions and compensation for the loss of enzyme activity which may have occurred as a result of the accumulation of oxidosqualene. The antifungal activity of the plant extract on ergosterol production by A. flavus may also be due to saponins which target the cell membrane and ergosterol production in fungi. The effect of the plant extract on the fungal cell wall of A. flavus also showed that the plant extract caused a decline in β-(1, 3) glucan production by inhibiting β-glucan synthase. The plant extract also affected the chitin synthesis pathway of A. flavus, by causing a decline in chitin production, which was due to the inhibition of chitin synthase. Investigation of chitinase production using 4MU substrates showed that the plant extract caused an accumulation of chitobioses, by activating chitobiosidases and endochitinases. A decline in N-acetylglucosaminidase activity in the presence of the plant extract was observed and this prevented the formation of N-acetylglucosamine. The accumulation of chitobiosidase and endochitinase may be as a result of autolysis that may be triggered by A. flavus as a survival mechanism in the presence of the plant extract and as a compensatory mechanism for the loss of β-glucans and chitin. The antifungal effect of the plant extract on various components of the cell wall of A. flavus, makes T. violacea aqueous plant extract an ideal chemotherapeutic agent against both human and plant pathogens of Aspergillus. The broad spectrum of antifungal activity of T. violacea against A. flavus also eliminates any chances of the fungus developing resistance towards it and would make it a candidate for use as a potential antifungal agent. Further identification and possible chemical synthesis is needed to shed light on the safety and efficacy of the active compound for further development as a chemotherapeutic agent.
46

Studies on thiarubrine, a naturally occurring disulfide polyine

Constabel, Carsten Peter January 1988 (has links)
Chemical and biological aspects of thiarubrine, a highly antifungal dithiacyclohexadiene polyine, were investigated. A tissue culture system for the production of thiarubrines was developed by culturing hairy roots of Chaenactis douglasii induced by Agrobacterium rhizogenes strain TR7. One culture line accumulated two times the levels of thiarubrines of nontransformed control root cultures, while maintaining rapid growth. The combination of fast growth and high thiarubrine accumulation could not be duplicated in controls by adding exogenous NAA to the culture medium. Hairy root cultures also produced less thiarubrine B relative to thiarubrine A compared to controls. Thiarubrine synthesis appears to be closely correlated with degree of tissue differentiation; it is suggested that it may be more practical to improve the growth rate of thiarubrine-producing root cultures by transformation rather than seek to induce synthesis in fast-growing suspension cultures. The biosynthetic relation between thiarubrines and the always co-occurring thiophenes was investigated by performing ³⁵S tracer experiments with C. douglasii hairy root cultures. It is possible that the thiophenes are not actively synthesized by the roots but rather are products of thiarubrine decomposition resulting from the extraction procedures and other manipulations of the cultures. The in vitro conversion of thiarubrine to thiophene can be induced by light, heat and other agents. No turnover of thiarubrines could be detected in the cultures in late logarithmic or stationary phases of the growth cycle. I Thiarubrines show strong light-independent antibacterial and antifungal activity. The mechanism of action of thiarubrine against E. coli and S. cerevisiae was investigated using comparative disk bioassays. A very similiar polyine from Rudbeckia hirta was as active as thiarubrine in the dark, indicating the central role of the disulfide ring in toxicity of the compounds. Visible light enhanced this activity suggesting that decomposition of the disulfide ring is important for its antibiotic effects. The photodegradation product, a thiophene, is phototoxic, probably via both type I and type II photosensitization mechanisms. The root culture extracts of Rudbeckia hirta yielded a new isomer of a known dithiacyclohexadiene polyine. MS and NMR analyses confirmed the cis configuration of this isomer. / Science, Faculty of / Botany, Department of / Graduate
47

Red-emitting carbon dots and their biological application as antifungal/anti-biofilm agent

Huang, Regina 27 May 2020 (has links)
Carbon dots (CD) have emerged as the new eye-catching theranostic nanomaterials due to their distinctive features, including tunable emission, facile surface modification, high biocompatibility and low cytotoxicity. These distinguishing features allow full customizations of CD according to the needs of various studies. Of note, they have been widely employed as nano-vehicles with live-tracking systems in many biological applications to deliver medicine with low bioavailability to targeted sites. Candida albicans, a commonly seen commensal fungus accounts for life-threatening infections in humans, is the leading cause of oral candidiasis. Yet, the efficacy of the "gold standard" Amphotericin B (AmB) has been limited due to poor water solubility and dose-dependent cytotoxicity. In addition, the interactions of CD with Candida cells/biofilms and human epithelial tissues have not been fully investigated, and very limited studies have been done on CD-based antifungal drugs delivery for topical administration. Herein, AmB-conjugated guanylated CD (CD-Gu + -AmB) tackling oral fungal infections were synthesized and possessed potent antifungal/anti-biofilm effects against C. albicans. Moreover, CD-Gu + -AmB exhibit low cytotoxicity to primary human oral keratinocytes and can selectively accumulate in the cell nuclei. Above all, the first evidence of studying the penetration and exfoliation profiles of CD in a three- dimensional organotypic human oral epithelial tissue model was provided, and the accumulation of CD-Gu + -AmB in the epithelial tissue can form a 'shielding' layer on oral epithelia against C. albicans. This study demonstrates that CD-Gu + -AmB may serve as a promising antifungal agent for tackling C. albicans and Candida-induced oral candidiasis through fast epithelial penetration, extra-/intra-cellular embedding and gradual exfoliation
48

A study on antifungal proteins, ribonucleases and hemagglutinins, examples of defense proteins. / CUHK electronic theses & dissertations collection

January 2004 (has links)
Xia Lixin. / "August 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 210-224). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
49

A biochemical study of defense proteins: hemagglutinin, hemolysin and antifungal protein.

January 2007 (has links)
Leung, Ho Wai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 136-146). / Abstracts in English and Chinese. / THESIS COMMITTEE --- p.II / ACKNOWLEDGEMENT --- p.III / ABSTRACT --- p.IV / CHINESE ABSTRACT --- p.VI / TABLE OF CONTENT --- p.VII / OVERVIEW OF THIS PROJECT --- p.1 / Chapter SECTION 1: --- Purification and Characterization of hemagglutinins from French bean and mottled kidney bean / Chapter Chapter 1 --- INTRODUCTION / Chapter 1.1 --- General Introduction --- p.2 / Chapter 1.2 --- Physiological functions of plant lectins --- p.6 / Chapter 1.3 --- Physiological functions of animal lectins --- p.9 / Chapter 1.4 --- Biological functions of lectins --- p.12 / Chapter 1.5 --- Clinical and research applications of lectins --- p.16 / Chapter 1.6 --- Legume lectins --- p.17 / Chapter 1.7 --- Isolation and purification of lectins --- p.19 / Chapter 1.8 --- Objectives of the present study --- p.21 / Chapter Chapter 2 --- MATERIALS AND METHODS / Chapter 2.1 --- Chemicals --- p.22 / Chapter 2.2 --- Assay of hemagglutinating activity --- p.24 / Chapter 2.3 --- Purification protocol --- p.26 / Chapter 2.4 --- Assay of saccharide inhibition of hemagglutination --- p.28 / Chapter 2.5 --- Assay of pH stability --- p.28 / Chapter 2.6 --- Molecular mass determination and N-terminal sequence determination --- p.28 / Chapter 2.7 --- Assay of mitogenic activity --- p.29 / Chapter 2.8 --- Assay of antiproliferative activity --- p.30 / Chapter 2.9 --- Assay for antifungal activity --- p.30 / Chapter 2.10 --- Assay of HIV-1 reverse transcriptase inhibitory activity --- p.31 / Chapter 2.11 --- Assay of stability towards trypsin and chymotrypsin --- p.31 / Chapter 2.12 --- Assay of nitric oxide production --- p.32 / Chapter 2.13 --- Assay ofHIV-1 integrase --- p.32 / Chapter Chapter 3 --- EXPERIMENTAL RESULTS / Chapter 3.1 --- Purification scheme --- p.35 / Chapter 3.2 --- Size determination and N-terminal sequencing --- p.36 / Chapter 3.3 --- Temperature stability assay --- p.37 / Chapter 3.4 --- pH stability assay --- p.37 / Chapter 3.5 --- Saccharides inhibition of hemagglutination --- p.37 / Chapter 3.6 --- Stability towards Trypsin and Chymotrypsin --- p.38 / Chapter 3.7 --- Anti-proliferative activity --- p.38 / Chapter 3.8 --- HTV-1 reverse transcriptase inhibition --- p.39 / Chapter 3.9 --- Mitogenic activity --- p.39 / Chapter 3.10 --- Nitric oxide production --- p.39 / Chapter 3.11 --- HIV-1 integrase --- p.39 / Chapter 3.12 --- Defensin --- p.40 / Chapter Chapter 4 --- DISCUSSION / Chapter 4.1 --- Purification scheme --- p.68 / Chapter 4.2 --- Sequence comparison --- p.69 / Chapter 4.3 --- Physical Stability of the hemagglutinins --- p.70 / Chapter 4.4 --- Protease Stability --- p.71 / Chapter 4.5 --- Sugar Specificity Assay --- p.72 / Chapter 4.6 --- Anti-proliferative Aactivity toward Cancer Cells --- p.73 / Chapter 4.7 --- HTV-1 reverse trancriptase and H̐ơþV integrase inhibition --- p.74 / Chapter 4.8 --- Mitogenic activity --- p.75 / Chapter 4.9 --- Antifungal protein --- p.76 / Chapter Chapter 5 --- CONCLUSION --- p.78 / Chapter SECTION 2: --- Purification and Characterization of flammulolysin from mushroom Flαmmulinα velutipes / Chapter Chapter 1 --- INTRODUCTION / Chapter 1.1 --- General Introduction --- p.79 / Chapter 1.2 --- Mechanisms of hemolysis --- p.80 / Chapter 1.3 --- Biological role of hemolysins --- p.80 / Chapter 1.4 --- Mushroom hemolysin --- p.82 / Chapter 1.5 --- Applications of hemolysins --- p.83 / Chapter 1.6 --- Objectives of the present study --- p.83 / Chapter Chapter 2 --- MATERIALS AND METHODS --- p.84 / Chapter Chapter 3 --- EXPERIMENTAL RESULTS / Chapter 3.1 --- Purification and sequence determination --- p.90 / Chapter 3.2 --- Effect of sugars and salts on hemolysin --- p.90 / Chapter 3.3 --- Effect of Temperature and pH on hemolysin --- p.91 / Chapter 3.4 --- Effect of Proteases on hemolysin --- p.91 / Chapter 3.5 --- Effect of osmotic protection on hemolysin --- p.91 / Chapter 3.6 --- Effect of hemolysin on tumor cells --- p.91 / Chapter 3.7 --- Effect of hemolysin on spleen cells --- p.92 / Chapter 3.8 --- Effect of hemolysin on bacterial growth --- p.92 / Chapter 3.9 --- Effect of hemolysin on fungal growth --- p.92 / Chapter Chapter 4 --- DISCUSSION / Chapter 4.1 --- Purification and sequence comparison of hemolysin --- p.103 / Chapter 4.2 --- Sugar and Salts inhibition --- p.104 / Chapter 4.3 --- Temperature stability --- p.105 / Chapter 4.4 --- pH stability --- p.106 / Chapter 4.5 --- Protease stability --- p.106 / Chapter 4.6 --- Osmotic Protection --- p.106 / Chapter 4.7 --- Anti-tumour activity of the hemolysin --- p.107 / Chapter 4.8 --- Anti-fungal activity --- p.108 / Chapter Chapter 5 --- CONCLUSION --- p.109 / Chapter SECTION 3: --- Purification and Characterization of antifungal peptide from buckwheat seeds Fagopyrum esculentum / Chapter Chapter 1 --- INTRODUCTION / Chapter 1.1 --- Plant antiftmgal proteins --- p.110 / Chapter 1.2 --- Classification of antifungal proteins --- p.110 / Chapter 1.3 --- Distribution of antifungal proteins in plants --- p.111 / Chapter 1.4 --- Mechanisms of antifungal activity --- p.111 / Chapter 1.5 --- Future Perspectives of Antifungal proteins --- p.112 / Chapter 1.6 --- Antifungal peptide from Buckwheat --- p.112 / Chapter 1 .7 --- Objectives of the present study --- p.113 / Chapter Chapter 2 --- MATERIALS AND METHODS --- p.114 / Chapter Chapter 3 --- EXPERIMENTAL RESULTS / Chapter 3.1 --- Purification and sequence determination --- p.118 / Chapter 3.2 --- Effect on anti-fungal activity --- p.118 / Chapter 3.3 --- Effect of temperature and pH on antifungal activity --- p.118 / Chapter 3.4 --- Effect of the antifungal peptide on tumor cells --- p.119 / Chapter 3.5 --- Effect of antifungal peptide on HIV-1 Reverse transcriptase Activity --- p.119 / Chapter 3.6 --- Effect of antifungal peptide on spleen cells and NO Production --- p.119 / Chapter Chapter 4 --- DISCUSSION / Chapter 4.1 --- Purification scheme and N-terminal sequence --- p.130 / Chapter 4.2 --- Antifungal Activity --- p.131 / Chapter 4.3 --- Physical stability --- p.131 / Chapter 4.4 --- Anti-proliferative activity toward cancer cells --- p.131 / Chapter 4.5 --- HTV-1 Reverse Transcriptase Inhibitory activity --- p.132 / Chapter 4.6 --- Mitogenic activity and nitric oxide production --- p.132 / Chapter Chapter 5 --- CONCLUSION --- p.133 / OVERALL CONCLUSION --- p.134 / REFERENCES --- p.136
50

Utilização de microrganismos e nanofibras funcionalizadas como agentes de controle de fungos toxigênicos

Veras, Flávio Fonseca January 2016 (has links)
Fungos filamentosos com capacidade de produzir micotoxinas podem estar presentes em alimentos, desde o cultivo até o produto após industrialização. Devido a isso, estratégias para controlar o crescimento fúngico devem ser investigadas, a fim de evitar o desenvolvimento desses microrganismos, bem como a produção de suas toxinas nos alimentos. Neste trabalho, duas abordagens para o controle de fungos toxigênicos foram avaliadas. A primeira estratégia foi a utilização de bactérias provenientes de diferentes ambientes aquáticos, sendo que 10 linhagens de Bacillus spp. e a linhagem Pseudomonas sp. 4B foram testadas quanto à influência sobre os parâmetros de crescimento (taxas de crescimento micelial, esporulação e germinação de esporos) de fungos toxigênicos (Aspergillus e Penicillium) e formação de micotoxinas. Todas as bactérias foram capazes de inibir o crescimento dos fungos em meio de cultura, apresentando halos de inibição variando de 1,0 até 15,7 mm. Bacillus sp. P11 apresentou resultados mais expressivos em relação às demais linhagens do gênero Bacillus com maiores valores de redução na maioria dos parâmetros de crescimento. Além disso, Bacillus sp. P11 e Pseudomonas sp. 4B apresentaram efeito sobre as taxas de crescimento micelial, esporulação e germinação de esporos, com níveis de redução acima de 43,3, 32,1 e 84,1% respectivamente. Mesmo assim, as demais linhagens também apresentaram resultados satisfatórios sobre esses parâmetros. Estas bactérias também reduziram a síntese de aflatoxina B1 e ocratoxina A em mais de 94 e 63%, respectivamente, quando cultivadas simultaneamente com os fungos produtores de cada micotoxina. Adicionalmente, a capacidade de Bacillus sp. P11 em produzir os lipopeptídeos iturina A (167,9 mg/mL de extrato butanólico) e surfactina (361,9 mg/mL de extrato butanólico) foi confirmada. Estes compostos podem ter contribuído para a atividade antifúngica desta bactéria. A segunda estratégia investigada neste estudo para controlar o desenvolvimento de fungos toxigênicos foi o emprego de nanofibras de poli-ɛ-caprolactona (PCL) incorporadas com cetoconazol e natamicina como material antimicrobiano. Nesta abordagem, as nanofibras foram produzidas pela técnica de eletrofiação e posteriormente caracterizadas e avaliadas quanto ao seu potencial antifúngico. Nanofibras funcionalizadas com cetoconazol ou natamicina apresentaram atividade antifúngica contra os isolados toxigênicos uma vez que zonas de inibição variando de 6 a 44 mm foram observadas. Além disso, as análises de microscopia eletrônica e espectroscopia demonstraram que a incorporação dos antifúngicos não altera de forma expressiva as principais características das nanofibras. Também foi possível verificar a capacidade de liberação controlada dos antifúngicos durante 72 h de contato das nanofibras com diferentes soluções simulantes. Valores próximos a 80 e 45 μg/mL de cetoconazol e natamicina, respectivamente, foram observados em solução de Tween 20 (5%). Portanto, o processo de eletrofiação foi capaz de agregar propriedades antifúngicas às nanofibras de PCL. Os resultados demonstraram que as bactérias e os nanomateriais investigados neste estudo são promissores para o controle de fungos toxigênicos e produção de micotoxinas. / Filamentous fungi that have the potential to produce mycotoxins may be present in food, from cultivation to after industrialization. Therefore, several strategies to control fungal growth must be investigated in order to avoid the development of these microorganisms and the production of their toxins in food. In this work, two approaches to toxigenic fungi control were evaluated. The first one was the use of bacteria from different aquatic environments as biocontrol agents in which 10 Bacillus spp. strains and the Pseudomonas sp. 4B strain were tested in relation to the effect on growth parameters (mycelial growth, sporulation and spore germination rates) of toxigenic fungi (Aspergillus and Penicillium) and mycotoxin formation. All bacteria were able to inhibit the fungal growth in culture medium with inhibition zones ranging from 1.0 to 15.7 mm. It was also observed that Bacillus sp. P11 had better results compared to other Bacillus strains with larger reduction values in most of growth parameters. Furthermore, Bacillus sp. P11 and Pseudomonas sp. 4B exhibited effect on mycelial growth, sporulation and spore germination rates with reduction values above of 43.3, 32.1 and 84.1%, respectively. Even so, the other strains also showed satisfactory results on these parameters. Finally, these bacteria reduced the synthesis of aflatoxin B1 and ochratoxin A at levels above 94 and 63%, respectively, when co-cultivated with each mycotoxin producing fungi. Additionally, the ability of Bacillus sp. P11 to produce lipopeptides such as iturin A (167.9 mg/ml of butanolic extract) and surfactin (361.9 mg/ml of butanolic extract) was confirmed. These compounds may have contributed to antifungal activity of this bacterium. The second investigation of this work in order to control the growth of toxigenic fungi was the use of poly-ε-caprolactone nanofibers incorporated with ketoconazole and natamycin as antimicrobial material. In this approach, nanofibers were produced by the electrospinning technique and subsequently characterized and evaluated for their antifungal potential. Both nanofibers functionalized with ketoconazole and natamycin showed antifungal activity against toxigenic isolates since inhibitory zones ranging from 6 to 44 mm were observed. In addition, scanning electron microscopy and infrared spectroscopy analysis showed that the antifungals incorporation does not change the characteristics of nanofibers. It was also possible to verify the ability of controlled drug release during 72 h of nanofibers contact with different simulants solutions. Values near 80 and 45 μg/ml of ketoconazole and natamycin, respectively, were observed in the solution containing 5% Tween 20. Therefore, the electrospinning process was able to provide antifungal properties to the nanofibers. The results showed that bacteria and nanomaterials investigated in this study are promising for developing control strategies of toxigenic fungi and mycotoxin production.

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