Resumo 5'-ribonucleotídeos são moléculas de alto valor agregado amplamente utilizadas nas indústrias alimentícia e farmacêutica, em razão de suas propriedades bioativas. O presente trabalho visa produzir uma composição de 5'-ribonucleotídeos a partir de levedura residual cervejeira, como fonte de RNA, e radícula de malte cervejeiro, como fonte barata de 5'-fosfodiesterase (5'-PDE). A abordagem proposta mostrou-se promissora e com caráter inovador, pois ambas, levedura e radícula de malte, são resíduos do processo cervejeiro, estando intimamente ligadas em um ciclo que até o momento ainda não foi explorado comercialmente por falta de estudos. Os resultados do presente trabalho mostraram que a extração de 5'-PDE foi influenciada principalmente pelo tamanho das radículas e pela quantidade de solvente de extração (água). As principais moléculas formadas durante a hidrólise de RNA foram 5'-ribonucleotídeos, os quais representaram 85,86% do total de moléculas hidrolisadas. Por fim, os resultados deste trabalho podem gerar uma nova perspectiva para a indústria cervejeira no que se refere ao gerenciamento de seus resíduos, a fim de gerar a partir deles produtos de alto valor agregado e com ampla gama de aplicações.

Abstract 5'-ribonucleotides are high value-added molecules widely used in the food and pharmaceutical industries because of their bioactive properties. The present work aims to produce a composition of 5’-ribonucleotides using spent brewer’s yeast as cheap source of RNA, and barley malt rootlets as cheap source of 5'-phosphodiesterase (5'-PDE). This is a very promising and innovative strategy because both spent yeast and malt rootles are residues of the brewing process and are closely linked in a cycle that until now is not yet commercially exploited due to lack of studies. Our results showed that extraction of 5’-PDE was mainly influenced by the fineness of the rootlets and amount of extraction solvent (water). The main molecules formed during RNA hydrolysis were 5’-ribonucleotides, which represented 85.86% of the total hydrolyzed molecules. Finally, the results of the proposed approach can generate a new perspective for the brewing industry regarding the management of its wastes, generating from them products of high added value and with a wide range of applications.

Resumo A autólise de leveduras − um evento endógeno, lítico e irreversível, que ocorre nas células e é causado pela ação de enzimas intracelulares, proteases e carboidrases − é um processo bem conhecido e econômico. Todavia, a autólise apresenta um risco constante de grave contaminação microbiana, pois o caldo contém muitos nutrientes, além de o processo ser lento, favorecendo o crescimento de patógenos. O presente trabalho tem como objetivo acelerar a autólise de Saccharomyces cerevisiae, com foco no alto rendimento da produção de extrato de levedura por meio de uma tecnologia rápida, econômica e simples. A estratégia proposta tem como base a diminuição do pH da suspensão de levedura no início da autólise, por meio de um choque ácido, para ativar o sistema autolítico da célula em condições estressantes de temperatura e pH. Foi estudada a influência da concentração celular, da temperatura, do tempo e do choque ácido no início da autólise sobre o rendimento do extrato de levedura. Os melhores rendimentos de proteínas e sólidos totais foram observados para autólise tratada com choque ácido (H2SO4 10 µL/g de levedura seca e pH final 4,4) a 60 °C (extração de 36,84% de proteína e 48,47% de sólidos totais) e aumento gradual da temperatura 45 °C a 60 °C (extração de 41,20% de proteína e 58,48% de sólidos totais). O choque pôde aumentar a velocidade do processo, uma vez que o grupo controle atingiu cerca de 30% do extrato a 60 °C e o mesmo experimento, porém com choque ácido, atingiu mais de 43% em 12 h. Visto que o tempo em escala industrial é muito importante para a produtividade e para evitar riscos de contaminação por patógenos na autólise, tais resultados foram muito relevantes para fins industriais na produção de extrato de levedura, levedura autolisada, glucanas e mananas.

Abstract The yeast autolysis process - an endogenous and irreversible lytic event, which occurs in cells caused by the action of intracellular enzymes, proteases and carbohydrases - is a well-known and an economic process, however, there is a constant risk of serious microbial contamination since there are many nutrients in the broth and this process is slow, favoring the growing of pathogens. The present work comes up with an attempt to accelerate the autolysis of Saccharomyces cerevisiae with focus on the high yield of yeast extract production through a fast, economic and simple technology. The proposed strategy is based on decreasing the pH of the yeast suspension at the beginning of autolysis through an acid shock to activate the cell autolytic system under stressful conditions of temperature and pH. The influence of cell concentration, temperature, time and acid shock at the beginning of the autolysis on yeast extract yields were studied. The best yields of proteins and total solids were observed for autolysis treated with acid shock (H2SO4 10 µL/g of dried yeast and final pH 4.4) at 60 °C (36, 84% of protein and 48, 47% of total solids extracted) and gradual increase of temperature 45 to 60 °C (41.20% of protein and 58.48% of total solids extracted). The shock could increase the speed of the process since the control reached about 30% of extract at 60 °C and the same experiment, however, with acid shock reached more than 43% in 12 h. When considering time in an industrial scale, it could be noted that the time was very important for the productivity as well as avoiding risk of pathogen contamination in autolysis. These results were very relevant for industrial purposes in the production of yeast extract, autolyzed yeast and glucan and mannan.

In this study, the effects of the origin of xanthan used, in combination with chitosan, to prepare films for the treatment of skin lesions were evaluated. The characteristics of the films obtained with xanthan commercially available for the food industry sector and xanthan originated from a fermentation process conducted in a pilot plant were compared. Results showed that the source did not strongly interfere in many of the properties of the films, such as the mechanical properties, cytotoxicity to L929 cells, absorption of simulated body fluid and culture medium, stability in water and saline solution. Hence, even though the properties of biopolymers of different sources might vary, the films prepared with two distinct types of xanthan gum could be considered as potentially safe and similar in terms of relevant characteristics considering the aimed application.

The purpose of this study was to determine the Minimum Inhibitory Concentration (MIC) of pure or mixed chemicals for Saccharomyces cerevisiae and Lactobacillus fermentum in the samples isolated from distilleries with serious bacterial contamination problems. The biocides, which showed the best results were: 3,4,4' trichlorocarbanilide (TCC), tested at pH 4.0 (MIC = 3.12 mg/l), TCC with benzethonium chloride (CBe) at pH 6.0 (MIC = 3.12 mg/l) and TCC mixed with benzalkonium chloride (CBa) at pH 6.0 (MIC = 1.53 mg /l). If CBa was used in sugar cane milling in 1:1 ratio with TCC, a 8 times reduction of CBa was possible. This formulation also should be tested in fermentation steps since it was more difficult for the bacterium to develop resistance to biocide. There was no inhibition of S. cerevisiae and there were only antibiotics as an option to bacterial control of fuel ethanol fermentation by S. cerevisiae.

The present study evaluated the anti-inflammatory and analgesic properties of Agave sisalana Perrine in classic models of inflammation and pain. The hexanic fraction of A. sisalana (HFAS) was obtained by acid hydrolysis followed by hexanic reflux. Anti-inflammatory properties were examined in three acute mouse models (xylene ear oedema, hind paw oedema and pleurisy) and a chronic mouse model (granuloma cotton pellet). The antinociceptive potential was evaluated in chemical (acetic-acid) and thermal (tail-flick and hot-plate test) models of pain. When given orally, HFAS (5, 10, 25 and 50 mg/kg) reduced ear oedema (p < 0.0001; 52%, 71%, 62% and 42%, respectively). HFAS also reduced hind paw oedema at doses of 10 mg/kg and 25 mg/kg (p < 0.05; 42% and 58%, respectively) and pleurisy at doses of 10 mg/kg and 25 mg/kg (41% and 50%, respectively). In a chronic model, HFAS reduced inflammation by 46% and 58% at doses of 10 mg/kg and 25 mg/kg, respectively. Moreover, this fraction showed analgesic properties against the abdominal writhing in an acetic acid model (at doses of 5-25 mg/kg) with inhibitory rates of 24%, 54% and 48%. The HFAS also showed an increased latency time in the hot-plate (23% and 28%) and tail-flick tests (61% and 66%) for the 25 mg/kg and 50 mg/kg doses, respectively. These results suggest that HFAS has anti-inflammatory and analgesic properties.

The optimization of autolysis of Saccharomyces cerevisiae from brewery was studied aiming at the maximum ribonucleic acid extraction and yeast extract production. The best conditions for yeast autolysis was 55.2ºC, pH= 5.1 and 9.8% NaCl for 24h of processing, without the NH3 use. In these conditions, the RNA yield was 89.7%, resulting in 51.3% of dehydrated yeast extract with 57.9% protein. The use of 12.2% NH3 at 60ºC after autolysis (8h) and plasmolysis (8h) was not viable due to the reduction in the RNA yield from 89.7to78.4%. On the other hand, the thermal shock at 60ºC for 15 minutes prior to autolysis provided an increase in the yield from 89.7 to 91.4%. The autolysis, including NaCl plasmolysis in the optimized conditions was efficient, economic and with short time, thus usable for industrial purpose to obtain more valuable products such as yeast extract enriched in RNA and/or protein, for different applications.

O efeito antimicrobiano de vários produtos incluindo formulações comerciais usualmente utilizadas em usinas de açúcar e álcool foi determinado pelo teste da Concentração Mínima Inibitória (CMI) adaptada para Saccharomyces cerevisiae e os contaminantes naturais Lactobacillus fermentum and Leuconostoc mesenteroides. O teste da CMI foi feito pela adaptação do método da Macrodiluição em caldo pela formulação de um meio de cultivo com caldo de cana em condições similares ao mosto da fermentação alcoólica. Penicilina V Ácida (CMI= 0,10-0,20 µg/ml) e clindamicina (CMI = 0,05-0,40 µg/ml) foram os mais efetivos contra o crescimento bacteriano em 24 horas. Entre os produtos químicos, sulfito (CMI = 10-40 µg/ml), nitrito (CMI <117 µg/ml) e sulfato de cobre (CMI = 75-300 µg/ml) foram os mais efetivos. Etileno-bis-ditiocarbamato de zinco e manganês e dimetilditilcarbamato não apresentaram efeito inibitório satisfatório (CMI > 50 µg/ml). Metilditiocarbamato foi eficiente apenas para L. fermentum (CMI= 2,5 µg/ml) e S. cerevisiae (CMI= 5,0 µg/ml). Tiocianato (CMI= 1,2-5,0 µg/ml), bromofenato (CMI= 9-18 µg/ml) e n-alquildimetilbenzil cloreto de amônio (CMI= 1-8 µg/ml) afetaram o crescimento de S. cerevisiae em concentrações inibitórias similares à L. mesenteroides ou L. fermentum. Formaldeido foi mais efetivo contra as bactérias (CMI= 11,5-23 µg/ml) em ambos pHs (4,5 e 6,5) em relação à levedura (CMI= 46-92 µg/ml). Vários biocidas testados afetam seriamente o crescimento de S. cerevisiae, nas dosagens similares àquelas que inibem as bactérias, portanto estes produtos deveriam ser evitados, ou usados somente em condições especiais, para o controle bacteriano do processo de fermentação. Para esta etapa, o controle destes contaminantes por antibióticos é mais apropriado e efetivo.

The antimicrobial effect of several products including commercial formulations currently used in sugar and alcohol factories was determined by adapted MIC (Minimal Inhibitory Concentration) test on Saccharomyces cerevisiae and on natural contaminants Lactobacillus fermentum and Leuconostoc mesenteroides. The MIC test by macrodilution broth method was adapted by formulating of the culture medium with cane juice closely simulating industrial alcoholic fermentation must. Acid penicillin V (MIC 0.10-0.20 µg/ml) and clindamycin (MIC 0.05-0.40 µg/ml) were most effective against bacterial growth in 24 h. Among the chemicals, sulphite (MIC 10-40 µg/ml), nitrite (MIC <117 µg/ml) and copper sulphate (75-300 µg/ml) were the most effective. Zinc and manganese ethylene-bis-dithiocarbamate and dimethyldithiocarbamate did not show good inhibitory effect on bacteria (MIC > 50 µg/ml). Methyldithiocarbamate was efficient only on L. fermentum (MIC 2.5 µg/ml) and S. cerevisiae (MIC 5.0 µg/ml). Thiocianate (MIC 1.2-5.0 µg/ml), bromophenate (MIC 9-18 µg/ml) and n- alkyldimethylbenzylammonium cloride (MIC 1-8 µg/ml) affected S. cerevisiae at similar inhibitory concentration for L. mesenteroides or L. fermentum. Formaldehyde was more effective on bacteria (MIC 11.5 - 23 µg/ml) in both pH (4.5 and 6.5) than yeast (MIC 46-92 µg/ml). Several tested formulated biocides seriously affect S. cerevisiae growth in the similar dosages of the bacterial inhibition, so these products should be avoided or used only in special conditions for the bacterium control of fermentation process. For this step, the control of these contaminants by antibiotics are more suitable and effective.