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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.
1

Avaliação das atividades antimicrobiana e citotóxica de metabólitos secundários produzidos pela actinobactéria ACTMS-9H isolada da rizosfera de Paulinia cupana Kunth

LIMA, Sandrine Maria de Arruda 27 February 2013 (has links)
Submitted by Eduardo Barros de Almeida Silva (eduardo.philippe@ufpe.br) on 2015-04-17T14:49:44Z No. of bitstreams: 2 Dissertação Sandrine Lima.pdf: 902329 bytes, checksum: 83147db27edaf8354efe02565a0beca3 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-04-17T14:49:44Z (GMT). No. of bitstreams: 2 Dissertação Sandrine Lima.pdf: 902329 bytes, checksum: 83147db27edaf8354efe02565a0beca3 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2013-02-27 / CAPES / Os micro-organismos, em particular as actinobactérias, são conhecidos por produzir um vasto número de metabólitos secundários bioativos de interesse farmacêutico. O objetivo deste estudo foi investigar as atividades antimicrobiana e citotóxica de metabólitos secundários produzidos pela actinobactéria ACTSM-9H isolada da rizosfera de Paullinia cupana Kunth de Maués - Amazonas. Para identificação taxonômica da linhagem foram utilizadas as técnicas de caracterização fenotípica e molecular. A produção dos metabólitos secundários foi avaliada através da fermentação em cultivo submerso utilizando farinha de soja como substrato e em meio sólido utilizando arroz. A atividade antimicrobiana foi determinada através da técnica de microdiluição em caldo, a citotoxicidade através do método do MTT e a atividade hemolítica realizada frente a membrana plasmática de eritrócitos murinos. A actinobactéria foi identificada como Streptomyces hygroscopicus S75-5. No estudo bioguiado para a avaliação das atividades antimicrobiana e citotóxica o extrato metanólico da biomassa proveniente da fermentação em cultivo submerso apresentou melhor atividade, sendo escolhido para ser particionado com n-hexano, acetato de etila e 2-butanol. A prospecção química indicou a presença de alcalóides, açúcares redutores e saponinas nos extratos metanólico e fase butanólica. A fase butanólica apresentou atividades antimicrobiana e citotóxica, sendo fracionada. Quatro frações obtidas da fase butanólica foram analisadas por bioautografia e apresentaram pelo menos um composto com atividade frente a Staphylococcus aureus. A fração EB1 apontou a presença de um alcalóide (Rf 0,7) com atividade antimicrobiana na bioautografia. A atividade antimicrobiana da fração EB1 mostrou valores da CMI iguais ou abaixo de 3,9 μg/mL frente aos micro-organismos testados. Na atividade citotóxica, a fração EB1 apresentou valores da IC50 frente às linhagens tumorais humanas HEp-2, HT-29, NCI-H292 e HL- 60, sempre menores ou iguais a doxorrubicina, utilizada como padrão, sendo mais seletividade para HL-60 com IC50 de 0,009 μg/mL. Em conclusão, os metabólitos produzidos por Streptomyces hygroscopicus S75-5 apresentaram potentes atividades antimicrobiana e antitumoral, evidenciando a importância de estudos futuros visando o isolamento dos compostos responsáveis por esta atividade.
2

Optimizacija formulacije medijuma za proizvodnju antibiotika ciljanog delovanja primenom prirodnog izolata Streptomyces hygroscopicus / Optimization of media formulation for the production of antibiotics with target activity using the natural isolate Streptomyces hygroscopicus

Veličković Tatjana 01 March 2019 (has links)
<p style="text-align: justify;">Jedno od najvećih dostignuća u dvadesetom veku je bio pronalazak antibiotika i njihova primena u humanoj medicini. Međutim, vremenom se pokazalo da su izazivači bolesti mikroorganizmi koji &ldquo;uče&rdquo; i imaju sposobnost da se &ldquo;menjaju&rdquo;, &scaron;to neminovno dovodi do pojave antibiotske rezistencije, a čemu ide u prilog &scaron;iroko rasprostranjena upotreba antibiotika u lečenju pacijenata i primena humanih antimikrobnih lekova u veterini i fitofarmaciji. Razvoj novih i unapređenje postojećih farmaceutika zahteva ogromna ulaganja koja se mogu ali i ne moraju vratiti godinama. Prvi korak u razvoju novog farmaceutika je identifikacija ciljanog antibiotskog delovanja metabolita izabranog proizvodnog mikroorganizma, nakon čega sledi optimizacija uslova biosinteze u smislu sastava medijuma za proizvodnju.<br />Osnovni cilj ove doktorske disertacije je optimizacija formulacije medijuma za kultivaciju prirodnog izolata Streptomyces hygroscopicus u pogledu izvora makronutrijenata i njihovih količina, kako bi se metabolička aktivnost primenjenog proizvodnog mikroorganizma, u definisanim proizvodnim uslovima, usmerila ka sintezi antibiotika sa ciljanim delovanjem.<br />Optimizacijom formulacije medijuma za kultivaciju prirodnog izolata <em>Streptomyces hygroscopicus</em>, u primenjenim eksperimentalnim uslovima, odabrani su najpogodniji izvori makronutrijenata i definisane su njihove optimalne koncentracije za proizvodnju antibiotika sa ciljanim delovanjem. Utvrđeno je da je biosinteza baktericida efikasnih protiv <em>B. cereus</em> ATCC 10876, <em>S. aureus</em> ATCC 11632 i P. <em>aeruginosa</em> ATCC 27853 najizraženija u medijumu sa fruktozom, sojinim bra&scaron;nom i fosfatnim solima, dok je za dobijanje fungicida koji deluju na <em>C. albicans</em> ATCC 10231 i <em>A. niger</em> ATCC 16404 najadekvatnije primeniti medijum sa glukozom kao izvorom ugljenika i već pomenutim izvorima azota i fosfora pri čemu je odnos navedenih sastojaka medijuma specifičan za svaki test mikroorganizam. Sa tehnolo&scaron;kog aspekta, rezultati ovih istraživanja predstavljaju pouzdan izvor informacija za unapređenje proizvodnih karakteristika primenjenog biokatalizatora, izbor tehnike kultivacije, definisanje toka i optimizaciju postupka proizvodnje baktericida i fungicida sa krajnjim ciljem uvećanja razmera posmatranog bioprocesa.</p> / <p>One of the greatest achievements in the twentieth century was the invention of antibiotics and their application in human medicine. However, over time, it has been proven that disease susceptors are &quot;learning&quot; microorganisms and have the ability to &quot;change&quot;, which inevitably leads to the emergence of antibiotic resistance, which is in favor of widespread use of antibiotics in the treatment of patients and the application of human antibiotics in veterinary medicine and phytopharmacy. The development of new and the advancement of existing pharmaceuticals requires huge investments that may or may not be back for years. The first step in the development of a new pharmaceutical is the identification of the target antibiotic activity of the metabolite of the selected production microorganism, followed by the optimization of the conditions of biosynthesis in terms of composition of the production medium.<br />The main goal of this PhD thesis is the optimization of the formulation of the medium for the cultivation of the natural isolate Streptomyces hygroscopicus in terms of the source of macronutrients and their amounts, in order to direct the metabolic activity of the applied production microorganism, in the defined production conditions, towards the synthesis of antibiotics with targeted action. By optimizing the formulation of the medium for the culture of the natural isolate Streptomyces hygroscopicus, in the applied experimental conditions, the most suitable sources of macronutrients were selected and their optimal concentrations for the production of antibiotics with targeted action were defined. The biosynthesis of bactericides was found to be effective against B. cereus ATCC 10876, S. aureus ATCC 11632 and P. aeruginosa ATCC 27853 most pronounced in the medium with fructose, soy flour and phosphate salts, while for the production of fungicides acting on C. albicans ATCC 10231 and A. niger ATCC 16404 most appropriately apply a glucose medium as carbon source and already mentioned sources of nitrogen and phosphorus wherein the ratio of said ingredients to the medium is specific to each test microorganism. From a technological point of view, the results of these studies represent a reliable source of information for improving the production characteristics of the applied biocatalyst, a selection of cultivation techniques, defining the flow and optimizing the production of bactericides and fungicides with the ultimate goal of increasing the size of the observed bioprocess.</p>
3

Optimizacija biosinteze antagonista skladišnih patogena jabuke primenom Streptomyces hygroscopicus / Optimization of antagonists of storage apple pathogens biosynthesis by Streptomyces hygroscopicus

Mitrović Ivana 25 September 2018 (has links)
<p style="text-align: justify;">Plodovi jabuke su tokom čitave godine prisutni u ishrani beba, dece i odraslih ljudi zbog čega je kvalitet i zdravstevena bezbednost ovih namirnica od izuzetnog značaja. Veliki broj fitopatogenih gljiva su prouzrokovači bolesti jabuka međutim, među značajnim prouzrokovačima bolesti jabuka u skladi&scaron;tima spominju se gljive iz rodova Alternaria i Fusarium. Smatra se da su zdravstveno bezbedni plodovi jabuke pre svega zdravi plodovi, bez prisustva fitopatogenih gljiva i bez ostataka fungicida. Sve veća briga oko primene sintetičkih fungicida zbog njihove toksičnosti, razvoja rezistentnosti patogena na fungicide i &scaron;tetnih efekata na životnu sredinu i zdravlje ljudi, doveli su do potrebe za pronalaženjem alternative hemijskoj za&scaron;titi, a jedno od mogućih se ogleda upravo u primeni biotehnolo&scaron;kim postupkom proizvedenih agenasa. Budući da su visoki tro&scaron;kovi biotehnolo&scaron;ke proizvodnje osnovna prepreka za &scaron;iru primenu ovih agenasa, optimizacija uslova izvođenja biosinteze predstavlja najvažniji korak ka njenom prevazilaženju. Stoga je kao cilj istraživanja u okviru ove doktorske disertacije definisana optimizacija biosinteze antagonista skladi&scaron;nih patogena jabuke primenom Streptomyces hygroscopicus na nivou laboratorijskog bioreaktora u pogledu odabira izvora ugljenika i azota i količina izvora ugljenika, azota i fosfora u hranljivoj podlozi za biosintezu željenih antagonističkih agenasa, kao i parametara biosinteze sa posebnim osvrtom na intenzitet primenjene aeracije i me&scaron;anja. Analizom dobijenih rezultata zaključeno je da se podloga za kultivaciju S. hygroscopicus koja je sadržala glicerol i pored već prisutnog azota u podlozi nije sadržala dodatni izvor azota, pokazala kao najpogodnija za produkciju željenih antagonističkih agenasa efikasnih protiv izolata vrsta A. alternata i F. avenaceum. Rezultati optimizacije sastava hranljive podloge ukazuju da se primenom definisanih optimalnih vrednosti ispitivanih faktora, koje su: sadržaj glicerola od 20 g/l, sadržaj (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> od 0,25 g/l i sadržaj K<sub>2</sub>HPO<sub>4</sub> od 1,41 g/l u podlozi za biosintezu antagonista skladi&scaron;nih patogena jabuke primenom S. hygroscopicus, na osnovu definisanih matematičkih modela predviđaju sledeće vrednosti parametara toka i parametara uspe&scaron;nosti biosinteze antagonista skladi&scaron;nih patogena jabuke: rezidualni glicerol od 5,3418 g/l; rezidualni azot od 0,193 g/l; rezidualni fosfati od 0,8601 g/l; prečnik zone inhibicije rasta micelije izolata A. alternata KA10 od 28,22 mm; prečnik zone inhibicije rasta micelije izolata A. alternata T1Jg3 od 36,86 mm; prečnik zone inhibicije rasta micelije izolata F. avenaceum KA12 od 25,54 mm i prečnik zone inhibicije rasta micelije izolata F. avenaceum KA13 od 26,78 mm. Rezultati dobijeni ispitivanjem uticaja različitog intenziteta aeracije i brzine me&scaron;anja na biosintezu antagonista skladi&scaron;nih patogena jabuke primenom S. hygroscopicus u laboratorijskom bioreaktoru standardnih geometrijskih odnosa ukupne zapremine 3 l ukazuju da se primenom definisanih optimalnih vrednosti ispitivanih faktora, brzine me&scaron;anja od 100 o/min, intenziteta aeracije od 1,2 l/l/min i pri trajanju kultivacije od 96 h na osnovu definisanih matematičkih modela predviđaju sledeće vrednosti parametara toka i parametara uspe&scaron;nosti biosinteze antagonista skladi&scaron;nih patogena jabuke: rezidualni glicerol od 8,2645 g/l; rezidualni azot od 0,1723 g/l; rezidualni fosfati od 0,5167 g/l; suva materija 1,5023 g/l; prečnik zone inhibicije rasta micelije izolata A. alternata KA10 od 62,62 mm; prečnik zone inhibicije rasta micelije izolata A. alternata T1Jg3 od 61,09 mm; prečnik zone inhibicije rasta micelije izolata F. avenaceum KA12 od 45,55 mm i prečnik zone inhibicije rasta micelije izolata F. avenaceum KA13 od 43,02 mm. Validnost dobijenih rezultata potvrđena je izvođenjem biosinteze antagonista skladi&scaron;nih patogena jabuke na podlozi optimalnog sastava i primenom optimalnih procesnih parametara u laboratorijskom bioreaktoru standardnih geometrijskih odnosa ukupne zapremine 7l, a efikasnost produkovanih antagonističkih agenasa efikasnih na izolate A. alternata (KA10 i T1Jg3) i F. avenaceum (KA12 i KA13) potvrđena je i u in planta ogledima. Ostavreni rezultati optimizacije biosinteze antagonista skladi&scaron;nih patogena jabuke primenom Streptomyces hygroscopicus na nivou laboratorijskog bioreaktora predstavljaju osnovu za dalje uvećanje razmera do industrijskih, &scaron;to je ključni korak ka potencijalnoj industrijalizaciji predloženog proizvodnog postupka.</p> / <p>Apple fruits are available on the market all year round and their safety is of great importance for the consumers. Unfortunately, many phytopathogenic fungi can cause apple diseases but fungi from the genera Alternaria and Fusarium are listed among important storage pathogens of apple fruits. It is considered that health-safe apple fruits are primarily healthy fruits, without the presence of phytopathogenic fungi and without the remains of fungicides. Excessive use of pesticides in modern agriculture, including those used for control of fungal phytopathogens, has led to several problems related to pollution, environmental degradation and emergence of resistant strains. Biological<br />control of plant pathogens by means of microorganisms is considered as an attractive alternative to chemical-based treatments, with minimal impact on the environment. The main lack of biotechnology production of the antifungal agents are the high costs, so the optimization of the biosynthesis conditions is the most important step towards its overcoming. Therefore, the aim of this research is to optimize the medium composition and process conditions (agitation and aeration rate) of the antagonists of storage apple pathogens biosinthesis by Streptomyces hygroscopicus in laboratory-scale bioreactor. Based on the obtained results, it can be concluded that the S. hygroscopicus cultivation medium containing glycerol as a carbon source, with no additional nitrogen source, proved to be the most suitable for the production of the A. alternate and F. avenaceum antagonistic agents. The results of the optimization of medium for biosynthesis of the antagonists of storage apple pathogens using S. hygroscopicus indicated the following optimal values of the examined factors: the content of glycerol of 20 g/l, (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> of 0.25 g/l and K<sub>2</sub>HPO<sub>4</sub> of 1.41 g/l. By applying the defined optimal values and using the appropriate mathematical models, the following responses are predicted: residual glycerol of 5.3418 g/l; residual nitrogen of 0.193 g/l; residual phosphates of 0.8601 g/l; inhibition zone diameters of A. alternata KA10 of 28.22 mm; inhibition zone diameters of A. alternata T1Jg3 of 36.86 mm; inhibition zone diameters of F. avenaceum KA12 of 25.54 mm and inhibition zone diameters of F. avenaceum KA13 of 26.78 mm. Examining the effect of different agitation and aeration rate on the biosynthesis of antagonists of storage apple pathogens using S. hygroscopicus in a laboratory-scale bioreactor with total volume of 3 l, the following optimal values of the investigated factors are obtained: the agitation rate of 100 rpm, the aeration of 1.2 l/l/min and 96-hour as optimal time of cultivation. Bringing together the appropriate mathematical models and defined optimal values, the following responses are predicted: residual glycerol of 8.2645 g/l; residual nitrogen of 0.1723 g/l; residual phosphates of 0.5167 g/l; biomass content of 1.5023 g/l; inhibition zone diameters of A. alternata KA10 of 62.62 mm; inhibition zone diameters of A. alternata T1Jg3 of 61.09 mm; inhibition zone diameters of F. avenaceum KA12 of 45.55 mm and inhibition zone diameters of F. avenaceum KA13 of 43.02 mm. The validity of the results was confirmed by performing the biosynthesis of the antagonists of storage apple pathogens in the medium with optimal composition and the optimal process parameters in a laboratory-scale bioreactor with the total volume of 7l. The efficacy of produced antagonistic agents effective against A. alternata (KA10 and T1Jg3) and F. avenaceum (KA12 and KA13) isolates was confirmed in vitro and in planta. The results obtained within this research represents the basis for the further enlargement of the scale, which is a key step towards the potential industrialization of the proposed production process.</p>
4

Effects of some microelements on antifungal activity and biomass of the Actinomyces producing Validamycin-A

Luong, Huu Thanh, Vu, Thuy Nga, Ha, Thi Thuy, Nguyen, Kieu Bang Tam, Dao, Thi Hong Van 05 February 2019 (has links)
Validamycin A (Val-A) is an aminoglycoside's antibiotic with anti-fungal activity. Val-A synthesized by Streptomyces hygroscopicus strain depending on the growth and development of this actinomyces. In this study, the effects of Mn and Zn on the antifungal activity and biomass of the Streptomyces hygroscopicus were conducted. The results showed that micronutrients Mn, Zn had significant effects on biomass as well as antifungal activity of strain Streptomyces hygroscopicus- DA15. With the addition of Mn at a concentration of 1μg/l of the nutrient medium, biomass of Streptomyces hygroscopicus was 2.85±0.02g/ml, the anti-fungal Rhizoctoniasolani (R. solani) round diameter reached 3.5±0.2cm. With the addition of Zn=3μg/l of the nutrient medium, biomass of Streptomyces hygroscopicus DA15 was 4.5±0.02g/ml, the anti-fungal R. solani round diameter reached 3.4±0.2cm. / Validamycin A (val-A) là một loại kháng sinh có khả năng kháng nấm, được tổng hợp bởi xạ khuẩn Streptomyces hygroscopicus và phụ thuộc vào quá trình sinh trưởng, phát triển của xạ khuẩn. Bài báo này đánh giá ảnh hưởng của nguyên tố vi lượng Mn, Zn đến hoạt tính kháng nấm Rhizoctonia solani (R. solani) và sinh khối của chủng Streptomyces hygroscopicus DA15. Khi bổ sung Mn vào môi trường nuôi cấy với nồng độ 1μg/l, sinh khối của Streptomyces hygroscopicus- DA15 đạt 2,85±0,02g/ml, đường kính vòng kháng nấm đạt 3,5±0,2cm. Bổ sung Zn vào môi trường nuôi cấy với hàm lượng Zn=3μg/l, sinh khối của Streptomyces hygroscopicus DA15 đạt 4,5±0,02g/ml và đường kính vòng kháng nấm đạt 3,4±0,2cm.
5

A Rapid, Small-Scale Method for Improving Fermentation Medium Performance

Zhu, Yin January 2007 (has links)
Cell biomass and chemicals (e.g. bioactive compounds) can be produced by fermentation. Optimising a fermentation system involves optimizing many variables such as determining the effect of inoculum quality and media components, and selecting the most appropriate fermenter design and operating conditions (such as agitation aeration and fermentation mode). Identifying the optimal media is very important because it can significantly affect product concentration, yield and productivity. However, the media contains many components so many trials need to be done, which makes the process laborious, expensive, open-ended, and often time-consuming. The data generated from the many trials can be difficult to analyse. This study developed a rapid, inexpensive small-scale technique to identify how media components affected the growth of Streptomyces hygroscopicus and its production of a secondary metabolite, the anti-tumour agent rapamycin. A method was developed using microtitre plates to screen the effect of three concentrations of nine media components on cell growth and rapamycin production using the Box-Behnken experimental design. Firstly, the methodology for microtitre plates was developed, which involved characterizing the physical parameters of a fermentation system, identifying the incubation time to minimize evaporation, modifying the assay method to deal with the small sample volumes, and developing an alternative method to determinate the rapamycin concentration that was cheaper than the HPLC method. Data from shake flasks trials (the normal screening method) were used to validate the microtitre method and to assess the latter's usefulness in predicting scale-up effects. Six media components - sodium chloride (NaCl), di-potassium orthophosphate (K2HPO4), l-aspartic acid, l-arginine, l-histidine and salt (formula 1) solution - significantly affected culture growth and/or rapamycin concentration. The regression tree method was used to indicate the importance and critical concentration range of each factor. The Pearson's product-moment value indicated a good correlation between data from microtitre plates and shake flasks (cell growth: r=0.75 p=0.016 n=8; rapamycin concentration r=0.92 p=0.08 n=6). The speed of the microtitre plate and shake methods were compared by assessing the total cycle time and the time required for various stages in the method. Performance of each method was assessed as cost of media and equipment. Using microtitre plates to screen and optimise media in terms of biomass and secondary metabolite production is faster and cheaper than using shake flasks. Labour efficiency for the numerous, repetitive, small-scale experiments was substantially increased. Trials could be run without well-to-well cross contamination. The regression tree statistics methodology successfully showed the effect of input variables on target variables and identified effective medium component concentrations and any interactions. It is recommended that the microtitre plate procedure developed in this research may be applied to any study investigating the optimum media composition for growing other Streptomyces spp. strains, in screening studies when searching for new bioactive molecules, or for characterizing natural or recombinant/mutated micro-organisms.

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