Acuna, J.

Greiner, Ralf

Jorquera, M.

Menezes-Blackburn, D.

Sajidan, A.

English

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BIOAVAILABILITY 2014UNDERSTANDING THE BIOAVAILABILITY OF MICRONUTRIENTS AND BIOACTIVE COMPOUNDS SO AS TO IMPROVE PUBLIC HEALTHMAY 12-14, 2014 - HOTEL RECANTO - IGUASSU FALLS - BRAZIL25* Names, titles and abstracts are reproduced exactly as it was entered by the authors, therefore, replications and errors are their responsibility.EP-20 - THE BENEFITS OF USING A VEGETAL SEED SUPPLEMENTATION COMPLEMENTARY TO SELENIUM TREATMENT IN ACUTE EXPERIMENTAL INFECTION BY TRYPANOSOMA CRUZI Authors: PRISCILA MACHADO DE CERQUEIRA; ALINE RELVA; JACQUELINE DUNN; ANDRÉA PEREIRA DE SOUZA; TANIA C. DE ARAUJO-JORGE Institution: INSTITUTO OSWALDO CRUZ Country: BRASIL Session: TV4 - Date: 12/05/2014 - Room:  FOYER - Time: 10:24-10:29:00 BACKGROUNDChagas disease, caused by the protozoan Trypanosoma cruzi, remains a serious public health problem in Latin America. The symptomatic stages present distinct clinical forms, such as a cardiac and digestive intestinal disorders; chronic constipation is a common symptom caused by infection. In this context dietary treatment could be a key in the modulation of  the disease processes and treating the clinical symptoms. Food rich in dietary fibers and phenolic compounds have been investigated because of  their functional properties.OBJECTIVESTo evaluate the effect of  dietary supplementation with vegetal seed (VS) on the clinical parameters of  acutely T. cruzi-infected Swiss mice.METHODSSwiss mice were infected with Y strain of  T. cruzi and followed clinically and parasitologically for 3 weeks, under a dietary treatment with selenium with or without VS. We evaluated weight consumption, intestinal transit, stool frequency and parasitemia. Mice received an aqueous suspension of  charcoal by gavage and the time of  its appearance in the feces determined the intestinal transit of  infected and non-infected animals, in the selenium supplemented groups with or without VS.RESULTSInfected animals lost weight in second week post infection, independently of  VS supplementation, indicating that weight decrease can not be only attributed to a burst in TNF production but also to a net reduction on food intake. Selenium has a beneficial effect in intestinal transit delay commonly seen in infected mice; supplementation with VS lead to a shorter (p<0,05) intestinal transit time and decreased the frequency of  defecation, as compared to infected non-supplemented animals.CONCLUSIONSThese results indicate that this nutritional approach can de suggested as an adjuvant therapy for intestinal disorders caused by T. cruzi.EP-19 - IMPROVING TEMPERATURE STABILITY OF ESCHERICHIA ALBERTII PHYTASE BY ERROR-PRONE PCR Authors: RALF GREINER; ADJID SAJIDAN; DANIEL BLACKBURN-MENEZ; JACQUELINNE ACUÑA; MILKO JORQUERA Institution: MAX RUBNER-INSTITUT Country: GERMANY Session: TV4 - Date: 12/05/2014 - Room:  FOYER - Time: 10:18-10:23:00 BACKGROUNDPhytase [myo-inositol(1,2,3,4,5,6)hexakisphosphate phosphohydrolase], a phytate-specific phosphatase, is already used as a supplement in diets for simple-stomached animals to improve phosphate utilisation from phytate [myo-inositol(1,2,3,4,5,6)hexakisphosphate], the major storage form of  phosphate in plant seeds and grains. In recent years, this class of  enzymes has also found increasing interest to be used in food processing and manufacturing, particularly because reduction in dietary phytate is seen as a possibility to combat zinc and iron deficiencies by enhancing their bioavailability in plant-based foods. Several enzymatic properties of  the Escherichia albertii phytase make this enzyme attractive for biotechnological applications. For many applications however, a higher temperature stability of  the enzyme would be of  advantage.OBJECTIVESTherefore, improving thermal stability of  the Escherichia albertii phytase by error-prone PCR was the aim of  the studies.METHODSDirected evolution was applied to improve temperature stability of  the Escherichia albertii phytase. Error-prone PCR was performed using a plasmid containing the wild-type Escherichia albertii phytase encoding gene cloned into a Saccharomyces cerevisiae expression vector as a template. Approximately, 1500 clones were screened for increased temperature stability.RESULTSCompared with the wild-type enzyme, two variants (K46E and D144N/V227A) showed a significant increase in temperature stability. Compared to the wild-type phytase, the mutants showed a 33% (K46E) and a 95% (D144N/V227A) higher residual activity at 80°C after 10 min incubation. Overall catalytic efficiency (kcat /Km) of  K46E and D144N/V227A was improved by 36% and 97% compared to the catalytic efficiency of  the wild-type phytase at pH 4.5, respectively. Thus, the catalytic efficiency of  these enzymes was not inversely related to their temperature stability. From an economic point of  view it is worth mentioning that the mutants still exhibit excellent high specific activities.CONCLUSIONSIn summary, Escherichia albertii phytase variants with a better overall catalytic efficiency and improved temperature stability were obtained. These improvements make these enzymes better suited for the intended biotechnological applications.back to index

Improving temperature stability of escherichia albertii phytase by error-prone PCR

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Improving temperature stability of escherichia albertii phytase by error-prone PCR

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