Avaliação de produtos naturais no controle de biofilmes formados em sistema dinâmico

The biofilms microbial forms of association are responsible for generating, accelerating and / or induce the process of corrosion. The damage generated in the petroleum industry for this type of corrosion is significatives, representing major investment for your control. The aim of this study was to evaluate such tests antibiograms the effects of extracts of Jatropha curcas and essential oil of Lippia gracilis Schauer on microrganisms isolated from water samples and, thereafter, select the most effective natural product for further evaluation of biofilms formed in dynamic system. Extracts of J. curcas were not efficient on the complete inhibition of microbial growth in tests type antibiogram, and essential oil of L. gracilis Schauer most effective and determined for the other tests. A standard concentration of essential oil of 20 μL was chosen and established for the evaluation of the biofilms and the rate of corrosion. The biocide effect was determined by microbial counts of five types of microorganisms: aerobic bacteria, precipitating iron, total anaerobic, sulphate reducers (BRS) and fungi. The rate of corrosion was measured by loss of mass. Molecular identification and scanning electron microscopy (SEM) were performed. The data showed reduction to zero of the most probable number (MPN) of bacteria precipitating iron and BRS from 115 and 113 minutes of contact, respectively. There was also inhibited in fungi, reducing to zero the rate of colony-forming units (CFU) from 74 minutes of exposure. However, for aerobic and anaerobic bacteria there was no significant difference in the time of exposure to the essential oil, remaining constant. The rate of corrosion was also influenced by the presence of oil. The essential oil of L. gracilis was shown to be potentially effective

Diagnóstico regional do processo de queijo coalho comercializado em Natal/RN

Coalho cheese is a typical product of the Northeastern Brazil, which is consumed both raw and cooked. The present work aimed to study the characteristics of artisanal and industrial processes in the production of coalho cheese sold in Natal / RN in order to evaluate its quality and consumer s profile. Four artisanal cheeses plants were monitored and a questionnaire was sent to different cheese industries. Besides this, eight cheese samples (four artisanal and four industrial) were evaluated in regard to the microbiological quality, physical-chemical and sensory attributes. The sensory acceptance was evaluated by using 108 non-trained panelists by using the hedonic scale. The consumer s profile survey was applied to 400 consumers of coalho cheese. The lack of hygiene control was detected at the artisanal cheese production, which uses raw milk as its raw material. Research has shown that the industrialized cheeses are made from pasteurized milk provided by their own production or by a third party, as observed in cheese making dairies. In general, the results indicate variation in the manufacturing process of coalho cheese, which results in the lack of product standardization. Regarding the physical-chemical analysis, most artisanal and industrial samples presented moisture content between 36 and 40 %, classified as medium moisture cheese, which is the only parameter that showed no significant difference (p>0.05). However, the water activity (Aw), pH and acidity results differed significantly. All artisanal samples showed coliform contamination at 35 °C, which confirms the poor hygienic conditions. In regard to coliforms at 45 °C, 75 % of artisanal coalho cheese samples had value higher than 103 MPN / g, a value above the lawful limits determined by RDC nº 12. Fifty percent of industrial coalho cheese samples showed coagulase-positive Staphylococcus values above the limit allowed by the RDC nº 12, indicating poor handling. The sensory evaluation revealed that the taste was the only parameter that showed significant difference, and this difference was only between two industrial brands. The consumer s survey showed that the coalho cheese flavor is the most important reason for buying this kind of cheese. Although coalho cheese is mainly bought in supermarkets, open street markets and country shops are still important selling points. It is concluded that there is no coalho cheese standardization in the RN state, which leads to variations in physical-chemical and sensory attributes. Moreover, it is necessary greater hygiene control in the production and handling procedures of coalho cheese.

Avaliação de produtos naturais no controle de biofilmes formados em sistema dinâmico

The biofilms microbial forms of association are responsible for generating, accelerating and / or induce the process of corrosion. The damage generated in the petroleum industry for this type of corrosion is significatives, representing major investment for your control. The aim of this study was to evaluate such tests antibiograms the effects of extracts of Jatropha curcas and essential oil of Lippia gracilis Schauer on microrganisms isolated from water samples and, thereafter, select the most effective natural product for further evaluation of biofilms formed in dynamic system. Extracts of J. curcas were not efficient on the complete inhibition of microbial growth in tests type antibiogram, and essential oil of L. gracilis Schauer most effective and determined for the other tests. A standard concentration of essential oil of 20 μL was chosen and established for the evaluation of the biofilms and the rate of corrosion. The biocide effect was determined by microbial counts of five types of microorganisms: aerobic bacteria, precipitating iron, total anaerobic, sulphate reducers (BRS) and fungi. The rate of corrosion was measured by loss of mass. Molecular identification and scanning electron microscopy (SEM) were performed. The data showed reduction to zero of the most probable number (MPN) of bacteria precipitating iron and BRS from 115 and 113 minutes of contact, respectively. There was also inhibited in fungi, reducing to zero the rate of colony-forming units (CFU) from 74 minutes of exposure. However, for aerobic and anaerobic bacteria there was no significant difference in the time of exposure to the essential oil, remaining constant. The rate of corrosion was also influenced by the presence of oil. The essential oil of L. gracilis was shown to be potentially effective