Project description:The yeast Saccharomyces cerevisiae is an important component of the wine fermentation process and determines various attributes of the final product. However, lactic acid bacteria (LAB) are also an integral part of the microflora of any fermenting must. Various wine microorganism engineering projects have been endeavoured in the past in order to change certain wine characteristics, namely aroma compound composition, ethanol concentration, levels of toxic/ allergenic compounds etc. Most of these projects focus on a specific gene or pathway, whereas our approach aims to understand the genetically complex traits responsible for these phenotypes in a systematic manner by implementing a transcriptomic analysis of yeast in mixed fermentations with the LAB O. oeni. Our aim is to investigate interactions between yeast and LAB on a gene expression level to identify targets for modification of yeast and O. oeni in a directed manner. Our goal was to identify the impact that the common wine microorganism O. oeni (malolactic bacteria) has on fermenting yeast cells on a gene expression level. To this end we co-inoculated the yeast and bacteria at the start of fermentation in a synthetic wine must, using yeast-only fermentations witout O. oeni as a control.
Project description:Cocoa is a crop of cultural, nutritional and social importance in Latin America. Cocoa production is mainly supported by smallholders and is central for the food security of these farmer families. Despite being part of their everyday diet and an important source of antioxidants and other healthy bioactive compounds, cocoa cropping is also a solid source of stable incomes supporting the livelihood of farmer families. Water deficit stress is one of the main limiting factors affecting crop yields. The ability of plants to tolerate or recover from the effects associated with this abiotic stress is of immense importance in terms of improvement in the context of climate change. Despite the emergence of functional genomics and phenotyping tools to approach these responses, many of these mechanisms are still little understood for many tropical food crops such as cocoa. For a transcriptomic analysis were selected 2 cocoa genotypes, from a hydric stress assay established in a greenhouse. 5-month-old plants of T. cacao of the genotypes EET 8 and TSH565 were tested for water deficit trial. A divided plot experimental design was applied: the hydric state of the 2 genotypes was evaluated with two levels: field capacity and water deficit by irrigation suspension during a period that generates severe stress (Leaf Water Potential of -3.0 Mpa). The irrigation suspension lasted 52 days.
Project description:Cocoa protein content is a very interesting source for isolation of antioxidant bio-peptides, which can be used for the prevention of age-related diseases. We use microarrays to study the global genome expression of C. elegans fed with a peptide (13L) isolated from cocoa.
Project description:Cocoa intake has been associated with health benefits, improving cardiovascular function and metabolism, as well as modulating intestinal immune function. The aim of this study was to take an in-depth look into the mechanisms affected by the cocoa intake by evaluating the colonic gene expression after nutritional intervention, and to ascertain the role of the fiber of cocoa in these effects. To achieve this, Wistar rats were fed for 3-weeks with either a reference diet, a diet containing 10% cocoa (C10), a diet based on cocoa fiber (CF) or a diet containing inulin (I). At the end of the study, colon was excised to obtain the RNA to evaluate the differential gene expression by microarray. Results were validated by RT-PCR. The C10 group was the group with most changes in colonic gene expression, most of them down-regulated but a few in common with the CF diet. The C10 diet significantly up-regulated the expression of Scgb1a1 and Scnn1g and down-regulated Tac4, Mcpt2, Fcer1a and Fabp1 by twofold, most of them related to lipid metabolism and immune function. The CF and I diets down-regulated the expression of Serpina10 and Apoa4 by twofold. Similar patterns of expression were found by PCR. Cocoa consumption down-regulated genes related to the immune system (B cell and mast cell functionality), lipid metabolism in the colon tissue. Most of the beneficial effects attributed to cocoa were due not only to its fiber content, but also to the possible contribution of polyphenols and other compounds.
Project description:Cocoa pulp fermentation is a spontaneous process during which the natural microbiota present at cocoa farms is allowed to ferment the pulp surrounding cocoa beans. Because such spontaneous fermentations are inconsistent and contribute to product variability, there is growing interest in a microbial starter culture that could be used to inoculate cocoa pulp fermentations. Previous studies have revealed that many different fungi are recovered from different batches of spontaneous cocoa pulp fermentations, whereas the variation in the prokaryotic microbiome is much more limited. In this study, therefore, we aimed to develop a suitable yeast starter culture that is able to outcompete wild contaminants and consistently produce high-quality chocolate. Starting from specifically selected Saccharomyces cerevisiae strains, we developed robust hybrids with characteristics that allow them to efficiently ferment cocoa pulp, including improved temperature tolerance and fermentation capacity. We conducted several laboratory and field trials to show that these new hybrids often outperform their parental strains and are able to dominate spontaneous pilot scale fermentations, which results in much more consistent microbial profiles. Moreover, analysis of the resulting chocolate showed that some of the cocoa batches that were fermented with specific starter cultures yielded superior chocolate. Taken together, these results describe the development of robust yeast starter cultures for cocoa pulp fermentations that can contribute to improving the consistency and quality of commercial chocolate production.
Project description:Cocoa consumption is associated with beneficial effects on human health. This has been attributed to its polyphenol components and their oligomers, which have been shown to decrease the risk of cardiovascular and inflammatory diseases, metabolic disorders, and to play a role in cancer prevention. We tested cocoa modulation on the gene expression profile of colon cancer HT-29 cells using Affymetrix microarrays. Among the genes differentially expressed in HT-29 cells upon incubation with cocoa extract, 48 were identified as Interferon regulated genes using the INTERFEROME database. Furthermore, a BAN constructed using the Pathway Architect software revealed that STAT1, IF44 and AGT were all highly interconnected nodes.