Enriching nutritive value of cassava root by yeast fermentation

Cassava (Manihot esculenta) is extensively cultivated throughout the tropics and subtropics regions due to its ability to grow in diverse soil conditions and minimal management. Experiments were made to study the cassava root fermentation by yeasts in order to enhance the nutritive value of their products (fresh pulp and chips). Both cassava chip (CC) and fresh cassava root pulp (FCR) samples were fermented by Saccharomyces cerevisiae in solid-liquid media fermentation conditions during 132 hours and dried at 30ºC. Products were analyzed for proximate composition, mineral composition, essential aminoacids and antinutrient content. There were increases (p A mandioca (Manihot esculenta) é extensivamente cultivada nas regiões tropical e subtropical devido à sua habilidade de crescer em diveresas condições de clima e manejo. Experimentos foram efetuados para estudar o aumento do valor nutritivo de subprodutos derivados de raízes de mandioca (polpa fresca e raspas) por processos de fermentação. Amostras de raspas (RM) e de polpa fresca (PF) foram fermentadas por Saccharomyces cerevisiae, em condições de meio sólido-líquido durante 132 horas e secas a 30ºC. Foram avaliados a composição aproximada, composição mineral, aminoácidos essenciais e conteúdo de antinutrientes dos produtos obtidos. Houve aumentos (p < 0.01) em proteínas (30,4% em RM e 13,5% in PF) e conteúdo de gorduras (5,8% em RM e 3,0% in PF). Os subprodutos de mandioca fermentados por S. cerevisiae apresentaram baixos conteúdos de ácido hidrocianídrico (RM, 0,5 mg kg-1 e PF 47,3 mg kg-1). Houve aumento considerável de lisina nas raspas fermentadas (RMF). Valores aceitáveis de cor, textura e aroma das raspas de mandioca enriquecidas formam obtidos após 132 de bioprocessamento. Sugere-se que a RMF pode ser nutricionalmente melhorada para alimentação animal pelo uso de S. cerevisiae

A survey of Vibrio cholerae O1 and O139 in estuarine waters and sediments of Beira, Mozambique

This study determined whether the estuarine and freshwater environment in Beira, Mozambique, serves as a reservoir of Vibrio cholerae O1 and O139. Ninety-nine estuarine water samples were collected at 6 sites in Beira. An additional 54 samples were collected from rural areas around Beira which included 3 freshwater lake samples, 15 river, 5 pond, and 4 estuarine water samples, and an equivalent number of sediment samples, collected from the same sites as the water samples. In addition, fish scales from 5 ocean fish and 1 deep sea water sample were also collected. The samples were analysed for the presence of V. cholerae O1 and O139 using culture methods, the direct fluorescent antibody (DFA) method and polymerase chain reaction (PCR) using a single-primer pair for the ompW gene and a semi-nested PCR selecting for the ctxAgene, encoding subunit A of cholera toxin. DFA results showed 37 V. cholerae O1- and 6 O139-positive samples. Vibrio cholerae O1 and O139 were observed on the scales of 4 of the 5 fish. The findings of the study provided in situ evidence for V. cholerae O1 and O139, predominantly as viable but non-culturable cells in the aquatic environment of Beira. This is the first record of the presence of V. cholerae O139 in the estuarine environment on the coast of Africa.Keywords: Vibrio cholerae O1, Vibrio choleare O139, water quality, estuary, PCR, DF