Food fermentation is a method widely used in the past to extend the storage life of food. Numerous studies on fermented food have revealed that they not only have biopreservative properties but also health benefits. Lactic acid bacteria are the major group of microorganisms involved in food fermentation and the properties that influence food are primarily due to the compounds released from microorganisms such as organic acids and bacteriocins. Their health benefits are exerted through several mechanisms including inhibiting the growth of pathogenic bacteria and modifying the host immune response. A number of strains that have been investigated show different properties even between the same species thus emphasizing the importance of strain identification. To determine if some traditional fermented Swedish foods contain lactic acid bacteria, bacteria from four fermented Swedish foods (two surströmming and two sausages) were isolated using MRS broth. Bacterial isolates were examined for their colony and cell morphology and Gram staining and were found to be predominantly Gram-positive cocci or rods. 16S rRNA PCR amplifications of selected isolates was performed using universal prokaryotic primers and sequenced. The sequencing results showed that the bacterial isolates from Oskars surströmming Filéer and Gognacs medvurst were Lactobacillus sakei and the isolate from Mannerströms surströmming was Enterococcus sp. This study showed that the traditional Swedish fermented food evaluated did contain lactic acid bacteria.

Abstract Two regions of the genome of the Lactobacillus delbrueckii subsp. lactis bacteriophage LL-H were characterized, representing 14 % of the phage genome. The first region of 2497 bp contained genes encoding phage structural proteins and the second region of 2498 bp genes involved in lytic functions. The nucleotide sequences of the major capsid protein gene g34, a putative capsid morphogenesis gene (ORF178A), the gene mur encoding phage cell wall hydrolase (lysin), the gene hol (ORF107) encoding the cell membrane permeabilizing phage holin, and six other genes with unknown function were found. Identification of these genes was performed by amino acid sequencing of their encoded proteins (genes g34 and mur), by their physiological effect on E. coli (genes hol and mur), by sequence comparison (genes mur, hol, ORF178A), and by biochemical analysis of their encoded purified protein (gene mur). A promoter for the capsid protein encoding gene cluster was determined by primer extension method. A purification method suitable for large scale processing (cation exchange chromatography by expanded bed adsorption method) was developed for the phage LL-H lysin protein Mur. Purified Mur was biochemically determined as a N-acetylmuramidase, which was effective on cell walls of Lb. delbrueckii, Lb. helveticus, Lb. acidophilus and Pediococcus damnosus. Some biotechnological applications for the lysis genes hol and mur or the purified protein Mur are suggested. Mur digests E. coli cell walls inefficiently, but could still be used for lysis of E. coli. Coexpression of the phage LL-H lysin and holin genes yielded to lysis of the E. coli host only at low culture densities. Therefore, some chemicals were tested for their ability to trigger lysis of E. coli cells overexpressing the phage LL-H gene mur. Thymol was found to mimic the physiological effects of the phage holin in a bacterial growth state independent manner. An efficient lysis method utilizing intracellular production of Mur and triggering the lysis with thymol was developed.

Master of Science / Department of Chemistry / Kenneth J. Klabunde / In this study, low molecular weight nanocomposites of L-lactic acid were synthesized with Commercial, Nanoactive®, and Nanoactive Magnesium Oxide Plus®, each of which differs in both surface area and shape. Synthesis of the composites was carried out by refluxing the nanoparticles in a solvent suspension. Both methanol and 1-propanol were used during this work. Heating was necessary in order to achieve adequate dispersion of the particles before adding L-lactic acid. Upon addition of the lactic acid monomer, the reactants were refluxed for a total of 3 hours, followed by evaporation of the excess solvent. The products were characterized via DSC, TGA, FTIR, [superscript]1H and [superscript]13C NMR, UV-Vis, XRD, and TEM. Additionally, titrations were performed with the reactants to ensure the particles were not being consumed by the acid regardless of their size. The results of this study indicate that condensation reactions are the primary polymerization route of lactic acid and polymerization appears to initiate on the surface of the magnesium oxide particles, resulting in physically unique composites of lactic acid and magnesium oxide.

Master of Science / Food Science Institute / Randall K. Phebus / Due to the potential of Shiga toxin-producing Escherichia coli (STEC) contamination, beef processors use various antimicrobial interventions throughout the slaughter and fabrication processes to reduce risks of contaminating the food supply. Certain antimicrobials are approved and marketed for spraying onto chilled subprimal cuts; however, administering these treatments through commercial-scale equipment against foodborne pathogens is not fully validated. This study evaluated the efficacy of three common antimicrobial sprays, individually (Study 1) and combined (Study 2), against a rifampicin-resistant STEC cocktail (O26, O45, O103, O111, O121, O145, and O157:H7) using a commercial style subprimal spray cabinet. For Study 1, beef subprimals (n=16) were mist-inoculated with the cocktail (ca. 5 log CFU/cm²), followed by spray-treatment with individual antimicrobials [200 ppm peracetic acid (PAA), 2% Centron™ (sulfuric acid, sodium sulfate anhydrous and water mixture; CEN), 4.5% lactic acid (LA), or water (W)]. Study 1 was designed as randomized generalized block. After each treatment phase, STEC population reductions were quantified. As individual antimicrobial treatments, LA and PAA provided greater (P ≤ 0.05) STEC reductions (0.5 and 0.6 ± 0.08 log CFU/cm², respectively) compared to water (0.2 ± 0.08 log CFU/cm²), but the CEN reduction (0.4 ± 0.10 log CFU/cm²) was statistically similar to W. To test the efficacy of combined treatments on subprimal cuts in Study 2, a split-plot design was used using three replications. The inoculated subprimals (n=4) were first treated with PAA, LA, CEN, or W; vacuum packaged; and stored for 72 hours at 4°C. Each subprimal was then divided (n=16) and treated with each of the four antimicrobials as a second treatment. Cumulative reductions from the two treatments and storage ranged from 0.5 to 1.5 log CFU/cm² (± 0.3 log CFU/cm²); the greatest reduction was observed when subprimals were treated with LA followed by vacuum packaged storage and another LA application. Nevertheless, there was no statistical significance among treatments for a particular combination of treatments in Study 2. These studies indicate that the individual antimicrobial treatments evaluated are marginally effective for reducing STEC populations on chilled beef subprimal cuts during fabrication. Although there does not seem to be a specific combination of treatment that is more effective than another, the overall bacterial reduction may be improved by combining treatments when the beef is stored under vacuum packaged conditions and retreated upon bag opening, as typical of mechanical tenderization operations.

Pediococci are Gram-positive, non-spore forming lactic acid bacteria, LAB, that are commonly used in the industrial fermentation of vegetables and meat. On the other hand species of pediococci may constitute part of the secondary microflora as non-starter lactic acid bacteria, NSLAB, responsible for cheese ripening. This study was conducted to determine and isolate pediococci from South African farm-style cheese and to morphologically and physiologically characterize the pediococci isolates to a species level. Strains of Pediococcus species isolated from South African farm-style cheese were evaluated for the production of antimicrobial peptides, pediocins, and their effect against food pathogens Bacillus cereus ATCC 1178 and Listeria monocytogenes ATCC 7644. Eight farm-style cheeses namely pasteurized young Gouda (PYG), pasteurized matured Goude (PMG) as well as pasteurized matured Parmesan (PMP); un-pasteurised or raw milk aged Bouquet (RAB), aged Gouda (RAG) and matured Gouda (RMG) as well as goat cheese Gouda (:RGG) were chosen for the isolation of Pediococcus species. LAB were cultivated on MRS agar where logarithmic counts of LAB ranged from 6.90 cfu/g to 9.40 cfu/g. Microscopic examination of selected colonies identified 110 (18%) of 606 isolates as Gram-positive, catalase negative presumptive pediococci occurring in pairs, clusters and tetrads. Presumptive pediococci were distributed among five of the eight cheeses namely PYG, PMG, RAB, RAG and RMG in numbers of 33, 21,28, 12 and 16 respectively. Physiological characterization of presumptive pediococci isolates was determined under specific growth parameters, temperature, pH and salt (w/v). These isolates were characterized as P. acidilactici, forty-nine, and P. pentosaceus, sixty-one, isolates. For the antimicrobial assay three techniques namely, the agar disc, spot and overlay methods were evaluated. Comparisons on the sensitivity or susceptibility of two Lactococcus strains, L. diacetilactis NCDO 176 and L. lactis NCDO 605, to crude extract from P. acidilactici STI was assessed. The agar disc assay technique produced more reliable results compared to the other techniques and L. diacetilactis NCDO 176 was more susceptible to crude pediocin extract produced from P. acidilactici STI. A total of fifty-two strains (47%) from both species, twenty-seven (24%) P. acidilactici and twenty-five (23%) P. pentosaceus, exerted antagonism against L. diacetilactis NCDO 176 through the action of perdiocins. Among these strains thirteen (13%) of both species, seven (6%) P. acidilactici and six (7%) P. pentosaceus inhibited B. cereus ATCC 1178 while a total of thirty-seven strains (33%) of both species where, seventeen (15%) P. acidilactici and twenty (18%) P. pentosaceus showed inhibition against L. monocytogenes ATCC 7644. Among these strains inhibition of food pathogens was variable against L. monocytogenes ATCC 7644 and low against B. cereus ATCC 1178. Comparison of the antimicrobial activity of the two Pediococcus species showed similarity in the inhibition pattern, however, more strains of P. pentosaceus exerted antagonism against L. lactis NCDO 176 and L. monocytogenes ATCC 7644 compared to P. acidilactici. / Dissertation (MSc)--University of Pretoria, 2005. / Food Science / unrestricted

Ting is a cooked fermented sorghum food that is popular amongst southern Africans for its sour taste and unique flavour. However, major challenges are associated with large-scale production and marketing of this spontaneously fermented food due to inconsistent microbiological and sensory quality. The use of starter cultures may circumvent these limitations. Prior to engaging starter cultures, detailed knowledge of the microbial diversity and dynamics during fermentation is important. Therefore, the aim of this study was to investigate microbial diversity and dynamics during sorghum fermentations, and to clarify the role of starter cultures regarding the microbiological safety and consumer acceptance of sensory characteristics of fermented ting. A culture-independent approach, based on the use of PCR-denaturing gradient gel electrophoresis (DGGE), revealed that Lactococcus lactis, Lactobacillus curvatus, Weissella cibaria and some Enterobacteriaceae were predominant at the end of spontaneous sorghum fermentations. Culture-dependent methods indicated that Lb. fermentum, Lb. plantarum, Lb. rhamnosus, E. faecalis, E. mundtii, W. cibaria and L. lactis were predominant at the end of fermentation. These results not only indicated the predominant bacteria during sorghum fermentation, but also indicated that a combined approach is required to reveal microbial diversity and dynamics during spontaneous sorghum fermentations. Based on the above results, L. lactis, Lb. fermentum, Lb. plantarum and Lb. rhamnosus were evaluated as starter cultures for production of ting. All the starter cultures were able to ferment sorghum, but the lowest pH and highest lactic acid was produced in naturally fermented sorghum inoculated with L. lactis. This fermentation showed an increase in the number of lactic acid bacteria and yeasts, whilst pathogen counts decreased. Ting from this fermented gruel, in contrast to naturally fermented sorghum, had sensory properties preferred by panelists. The results indicated that the use of L. lactis in starter cultures may result in ting with consistent and acceptable attributes. / Thesis (PhD)--University of Pretoria, 2011. / Microbiology and Plant Pathology / unrestricted

During sustained exercise, working muscles must be supplied with adequate kinds and amounts of exogenous fuels, and the delivery rates of oxygen and oxidizable substrates should be matched. The study of metabolite fluxes and their regulation is therefore critical to the understanding of exercise metabolism. Lactate has received renewed attention from physiologists and biochemists with the realization that it is not only an end product of glycolysis, but also an important fuel for aerobic work. As an oxidizable fuel, this substrate may provide some performance advantage over other fuels such as glucose and free fatty acids. The goals of this thesis were: 1) to determine whether endurance-adapted animals can support higher plasma lactate turnover rates than sedentary animals; and 2) to investigate the major factors involved in the regulation of plasma metabolite turnover at the whole-organism level - using lactate as a model. Lactate turnover rates were measured by bolus injection of [U-¹⁴C]lactate in skipjack tuna, Katsuwonus pelamis, and in thoroughbred racehorses, Equus caballus. In tuna, turnover rates ranged from 112 to 431 umol min⁻¹ kg⁻¹ and they were positively correlated with lactate concentration (slope = 15.1, r = 0.92). This teleost is able to support higher plasma lactate turnover rates than expected for a mammalian lower temperature, and lactate is probably an important oxidizable fuel in this species. For comparative purposes, resting turnover rates of lactate and glucose were plotted versus body mass on a log-log scale for a wide range of mammalian species. These plots were linear, and they showed the same slope as the classic body mass vs metabolic rate relationship. Thoroughbred horses are likely to have an aerobic scope of 40-fold or more. One of their main physiological adaptations to exercise is the ability to increase hematocrit by more than one and a half-fold in response to exercise. In the present study, this adjustment allowed them to reach an A-V difference in 0₂ content of more than 23 vol% during maximal exercise, a much higher value than other mammals. Their lactate turnover rate and cardiac output were measured at rest and two levels of submaximal exercise (45 and 55 V0₂ max) to investigate the relationship between cardiovascular adjustments on plasma lactate turnover rate. Cardiac output ranged from 106 to 571 ml min⁻¹ kg⁻¹, and mean lactate turnover rate from 9.3 at rest, to 75.9 umol min⁻¹ kg⁻¹ at 55% V0₂ max. In contrast with the situation found in tuna, the lactate turnover rates of thoroughbreds were not elevated compared with other mammals, showing that the metabolic adaptations of these outstanding athletes do not include the ability to sustain higher lactate fluxes than sedentary animals. In horses, the contribution of plasma lactate oxidation to V0₂ is minimal, and this substrate is not an important oxidative fuel; lipid oxidation may represent their major pathway for aerobic energy production during exercise. The ability to oxidize plasma lactate at high rates is therefore not necessarily required for the "elite" performance of endurance exercise. This study also shows that both, plasma lactate concentration and cardiac output are positively correlated with turnover rate. The correlation between cardiac output and lactate turnover rate is independent of the relationship between plasma lactate concentration and turnover rate. Plasma metabolite concentration and cardiac output can be regulators of plasma metabolite turnover rate. It is proposed that these two variables are, respectively, the fine and coarse controls for flux rate adjustments during exercise. / Science, Faculty of / Zoology, Department of / Graduate

This study examined the relationship between expired non-metabolic CO₂ (EX CO₂) and the accumulation of blood lactate, while emphasis was placed on the ventilatory (EX CO₂ and VE/VO₂) and lactate threshold relationship. Twenty-one elite cyclists (15 males, 6 females) performed a progressive intensity bicycle ergometer test (PIT) during which ventilatory parameters were monitored on-line at 15 second intervals, and blood lactate sampling occured on each minute. Threshold values were determined for each of the three indices; excess CO₂ (EXTT), VE/V0₂ (VVTT), and blood lactate (LATT). The three threshold values (EXTT, VVTT, LATT) all correlated significantly (P<0.001) when each was expressed as an absolute VO₂ (1/min). A significant RM ANOVA (F=8.41, P<0. 001) and post hoc correlated t-tests demonstrated significant differences between the EIXTT and LATT (P<0.001) and the EXTT and VVTT values (P<0.025). The LATT occured at an average blood lactate concentration of 3.35 mmol/1, while the mean expired excess CO₂ volume at the EXTT was 14.04 ml/kg/min. Over an 11 minute range across the threshold values (EXTT and LATT), which were used as relative points of reference, the expired EXC02 volume (ml/kg/min) and blood lactate concentration (mmol/1) correlated significantly (r=0. 69, P<0. 001). Higher individual correlations over the same period of time <r=0.82 - 0.96, P <0.001) stress the individual nature of this relationship. Expired EXCO₂ volume appeared to track blood lactate levels over this 11 minute period when the significant threshold difference (1.35 min.) was taken into consideration. These results indicate a strong relationship between the three threshold values, although changes and expired EXCO₂ precede changes in blood lactate concentration and the ventilatory equivelant (VE/VO₂). Although changes in expired EXCO₂ volume appear to track changes in blood lactate concentration, blood lactate concentration can not be accurately predicted from expired EXCO₂ volume as the nature of this relationship varies between individuals and. appears to be influenced by gender. / Education, Faculty of / Curriculum and Pedagogy (EDCP), Department of / Graduate

Orientador: Eliana Aparecida de Rezende Duek / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T15:18:31Z (GMT). No. of bitstreams: 1 Mas_BrunaAntunes_M.pdf: 4024365 bytes, checksum: 4922b258d265a9070576f02830e45d40 (MD5) Previous issue date: 2011 / Resumo: Polímeros biorreabsorvíveis são amplamente empregados como arcabouços na engenharia tecidual. No entanto, devido à natureza hidrofóbica, técnicas de modificação de superfície embasadas na enxertia de grupos químicos funcionais e imobilização de moléculas bioativas são desenvolvidas no intuito de promover a biofuncionalização da superfície desses polímeros, ocasionando uma melhora significativa da interação célula /polímero. Este estudo teve por objetivo desenvolver e caracterizar uma superfície biomimética em arcabouços do copolímero poli (L-co-D,L ácido lático)- PLDLA, através da enxertia de grupos (-COOH) e imobilização de colágeno tipo I. Os arcabouços de PLDLA 70/30 foram obtidos pela técnica de lixiviação de porógenos e submetidos ao método de fotopolimerização oxidativa da superfície do material, seguido da copolimerização enxertiva do ácido acrílico (PLDLA-AAc) e imobilização do colágeno tipo I (PLDLA-Col). A superfície das amostras foi caracterizada por Microscopia Eletrônica de Varredura (MEV), Microscopia de Força Atômica (MFA), Espectroscopia de Reflectância Total Atenuada (FTIR-ATR), Espectroscopia de Fotoelétrons Excitados por raios-X (XPS) e ângulo de contato. As imagens da MFA e fotomicrografias da MEV demonstraram a formação de poros e rugosidade na superfície dos arcabouços de PLDLA-AAc e, deposição do colágeno com formação de uma estrutura fibrilar em pontos inespecíficos da superfície dos arcabouços do PLDLA-Col, resultando no aumento da rugosidade superficial de 149.5nm (PLDLA puro) para 295nm (PLDLA-Col). Os espectros de FTIR-ATR do PLDLA, PLDLA-AAc e PLDLA-Col confirmaram a presença dos mesmos picos de absorção para todos os tratamentos e, a presença dos picos em 1662 e 1559cm-1, típicos de amida I e II nas amostras de PLDLA-Col. A citocompatibilidade dos arcabouços foi avaliada através do cultivo de células osteoblásticas primárias submetidas aos ensaios de citotoxicidade e adesão celular inicial, síntese de colágeno e observação da morfologia celular, obtidas pela MEV. Os resultados obtidos mostraram que a superfície biomimética dos arcabouços de PLDLA-Col melhora, significantemente, a taxa de adesão e proliferação celular bem como estimula a síntese de colágeno (p<0,01). Estes resultados são indicativos de que o método de modificação de superfície utilizado no presente estudo pode ser usado no desenvolvimento de arcabouços bioativos e biomiméticos com potencial aplicação na engenharia tecidual / Abstract: Bioreabsorbable polymers are widely used as scaffolds in tissue engineering. However, due to their hydrophobic nature, modification techniques based on graft of chemical functional groups and immobilization of bioactive molecules have been developed, in order to promote biofuncionalization of material surface, causing better interaction between cell / polymer. This study aimed at developing and characterizing a biomimetic surface on scaffolds of the copolymer poly (L-co-D, L lactic acid) (PLDLA 70/30), by grafting of chemical functional groups and immobilized with collagen type I. The scaffolds were obtained by porogen leaching, and submitted to photo-oxidation method of the material surface followed by grafting polymer polymerization of the acrylic acid solution (PLDLA-Acc) and immobilization of the type I collagen (PLDLA-Col). The sample surfaces were characterized by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) , Attenuated Total Reflectance Infrared Spectroscopy (ATR-FTIR), X-ray Photoelectron Spectroscopy (XPS) and contact angle. AFM images and SEM electromicrographs exhibited porous formation and roughness on the PLDLA-AAc surfaces and collagen deposition with net-like fibrillar structure in non-specific areas of the PLDLA-Col scaffolds, resulting an increase in surface roughness from 149.5 nm (PLDLA pure) to 295nm (PLDLA-Col). ATR-FTIR spectra of PLDLA, PLDLA-AAc and PLDLA-Col exhibited the same absorption peaks for all samples, as well as peaks of 1662 and 1559cm-1 , typical of amide I and II in PLDLA-Col samples. Scaffolds cytocompatibilty was evaluated by osteoblastic-like cell culture, submitted to cytotoxicity and initial cell adhesion assays, collagen synthesis and observation of cell morphology obtained by SEM. The result showed that biomimetic surface of PLDLA-Col scaffolds significantly improves adhesion and cell proliferation rates, as well as stimulates collagen synthesis (p<0,01). These results indicate that the surface modification method in the present study can be used in the development of bioactive and biomimetic scaffold with potential application in tissue engineering / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

Orientadores: Lucia Helena Innocentini Mei, Marcos Akira D'Avila / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-26T15:02:32Z (GMT). No. of bitstreams: 1 Santos_LarissaGiorgettidos_M.pdf: 23548686 bytes, checksum: e066ca702d1acefc2c3a72890d4456f5 (MD5) Previous issue date: 2014 / Resumo: Biomateriais nanofibrosos, obtidos com polímeros sintéticos biodegradáveis pela técnica de eletrofiação (electrospinning), com ou sem a presença de bioativos, são scaffolds promissores para aplicação na engenharia de tecidos devido a similaridade com matrizes extracelulares (ECM) naturais. O poli (ácido lático) (PLA) é um polímero de grande interesse tecnológico devido às suas propriedades para aplicação nessa área. Sedum dendroideum é um fitoterápico conhecido cientificamente por suas propriedades antiinflamatórias e cicatrizantes, e amplamente utilizado pela medicina popular. Neste trabalho, membranas de PLLA foram obtidas através do processo de eletrofiação, com variação da concentração do polímero (2,5%, 5%, 7,5% 10% e 12,5% m/v) e variação da taxa de vazão da solução no processo (2ml/h, 4ml/h e 6ml/h), buscando uma membrana com um menor diâmetro de fibra. A caracterização da massa molar, da isomeria, dos grupos químicos e do comportamento térmico do PLLA, foram feitas pelas técnicas de cromatografia de permeação (GPC), polarimetria, espectrometria no infravermelho (FT-IR), calorimetria diferencial de varredura (DSC) e Termogravimetria (TGA), respectivamente. O objetivo deste trabalho foi, além de obter membranas nanoestruturadas de PLLA por eletrofiação e caracterizá-la morfologicamente, foi incorporar extrato de S. dendroideum na membrana de menor diâmetro de fibra (7,5%) e investigar sua utilização no processo de cicatrização, com o intuito de otimizar as propriedades in vivo do material. Para tanto, foram realizados testes in vitro para análise do perfil de liberação do fitoterápico, no qual ficou constatado a libração do mesmo, e in vivo para verificar os efeitos da membrana como suporte na regeneração tecidual. Este estudo apresenta a eficácia das membranas de PLLA como suporte para liberação controlada do extrato de S. dendroideum e a sua capacidade em promover o reparo tecidual em lesões excisionais na pele do dorso de ratos Wistar. Os animais foram aleatoriamente divididos em cinco grupos: controle (C), animais tratados com membranas de PLLA (M), animais tratados com o extrato de S. dendroideum dissolvido em solução salina (F), animais tratados com membranas de PLLA com 10% de S . dendroideum (MF10), animais tratados com membranas de PLLA com 25% S. dendroideum (MF25). As amostras de tecidos foram colhidas no 2º, 6º e 10º dia após a cirurgia e foram submetidas a análise estrutural e morfológica. As observações experimentais mostraram a eficácia do fitoterápico incorporado na membrana, que promoveu um aumento significativo do número de células inflamatórias, a porcentagem de fibras colágenas maduras e birrefringentes e na espessura do epitélio em lesões cutâneas excisionais em ratos Wistar. Foi também demonstrado a aplicação das membranas de PLLA, sem o extrato, que promoveram respostas semelhantes no tecido lesionado, comprovando sua eficácia na aplicação como suporte para o crescimento de tecidos / Abstract: Nanofibrosos biomaterials, obtainde with biodegradable synthetic polymers through the electrospinning method, with or without bioactive molecules, are promising scaffolds in tissue engineering because of similarity to extracellular matrix (ECM) natural. Poly (lactic acid) (PLA) is a polymer of great interest due to its technological applications in this area. Sedum dendroideum is a herbal scientifically known for its anti-inflammatory and healing properties, and widely used in folk medicine. In this study, a PLLA membranes were obtained by electrospinning process, varying the polymer concentration (2.5%, 5%, 7.5% and 12.5% 10% w / v) and varying the flow rate solution in the process (2 ml / h, 4 ml / h and 6 ml / h) seeking a membrane with a smaller fiber diameter. The characterization of the molecular weight, of isomerism, chemical groups and the thermal behavior of PLLA were made by techniques permeation chromatography (GPC), polarimetry, infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermogravimetry (TGA), respectively. The aim of this work was in addition to getting nanostructured membranes of PLLA by electrospinning and morphologically characterize it, was incorporate S. dendroideum extract in the membrane of smaller fiber diameter (7.5%) and investigate their use in the healing process, in order to optimize the in vivo properties of the material. Therefore, in vitro tests were done to analyze the herbal release in which it was found the liberation of the same, and in vivo to check the effects of the membrane as support in tissue regeneration. This study shows the effectiveness of PLLA membranes as support for controlled release of the S. dendroideum extract and its ability to promote tissue repair in skin lesions excised from the back of Wistar rats. The animals were randomly divided into five groups: control (C) animals treated with PLLA membrane (M), animals treated with the extract of S. dendroideum dissolved in saline (F), animals treated with PLLA membranes with 10% S. dendroideum (MF10), animals treated with PLLA membranes with 25% S. dendroideum (MF25). Tissue samples were collected at 2nd, 6th and 10th days after surgery and underwent structural and morphological analysis. Experimental observations have shown the effectiveness of membrane embedded with herbal, which caused a significant increase in the number of inflammatory cells, the percentage of mature collagen fibers and birefringent and the thickness of epithelium in excising skin lesions in rats. It was also demonstrated the application of PLLA membranes without the extract, which promoted similar responses in the injured tissue, proving its effectiveness in application as support for tissue growth / Mestrado / Ciencia e Tecnologia de Materiais / Mestra em Engenharia Química