Search results for "Ferme"
showing 10 items of 1523 documents
Optimization of Bacillus cereus Fermentation Process for Selenium Enrichment as Organic Selenium Source
2020
Selenium is an essential trace element and micronutrient for human health. Application of organic selenium in plants and microorganisms as trace element supplement is attracting more and more attention. In this study, Bacillus cereus, an important probiotic, was used for selenium enrichment with sodium selenite as selenium source. The growth curve of B. cereus was investigated, and 150 μg/ml was selected as the concentration of selenium for B. cereus fermentation. With application of response surface methodology, the optimal fermentation conditions were obtained as follows: inoculation quantity of 7%, culture temperature of 33°C, and shaking speed of 170 rpm, leading to the maximal selenium…
Aerobic catabolism and respiratory lactate bypass in Ndh-negative Zymomonas mobilis
2018
Ability to ferment in the presence of oxygen increases the robustness of bioprocesses and opens opportunity for novel industrial setups. The ethanologenic bacterium Zymomonas mobilis performs rapid and efficient anaerobic ethanol fermentation, yet its respiratory NADH dehydrogenase (Ndh)-deficient strain (ndh-) is known to produce ethanol with high yield also under oxic conditions. Compared to the wild type, it has a lower rate of oxygen consumption, and an increased expression of the respiratory lactate dehydrogenase (Ldh). Here we present a quantitative study of the product spectrum and carbon balance for aerobically growing ndh-. Ldh-deficient and Ldh-overexpressing ndh- strains were con…
The Wine: typicality or mere diversity? The effect of spontaneous fermentations and biotic factors on the characteristics of wine
2016
Abstract Wine is probably one of the main fermented beverages for which the recognition of the “territoriality” is fundamental for its appreciation. The sensory profile of wine is significantly affected by microbial activities, and indigenous microorganisms may significantly contribute to the expression of wine typicality. The microbial ecology of wines is complex and includes several species and strains of yeasts, bacteria and molds. Several works showed the positive effects of spontaneous fermentations on the quality of wine as a consequence of the growth of different species and/or strains together at high levels. Furthermore, a new style of “natural” winemaking is gaining importance, si…
Inoculation of Torulaspora delbrueckii as a bio-protection agent in winemaking
2018
International audience; In oenology, bio-protection consists in adding bacteria, yeasts or a mixture of microorganisms on grape must before fermentation in order to reduce the use of chemical compounds such as sulphites. More particularly, non-Saccharvinyces yeasts are used as a total or partial alternative to sulphites. However, scientific data capable of proving the effectiveness of adding these yeasts on grape must is lacking. This study reports the analysis of antimicrobial and antioxidant effects of one non-Saccharamyces yeast, Torulaspora delbruecicii, inoculated at the beginning of the white winemaldng process in two Burgundian wineries as an alternative to sulphiting. The implantati…
Expression profile of genes involved in hydrogen sulphide liberation by Saccharomyces cerevisiae grown under different nitrogen concentrations
2009
AbstractThe present work aims to elucidate molecular mechanisms underlying hydrogen sulphide production in S. cerevisiae associated to nitrogen deficiency. To assess, at a genome-wide level, how the yeast strain adapted to the progressive nitrogen depletion and to nitrogen re-feeding, gene expression profiles were evaluated during fermentation at different nitrogen concentrations, using the DNA array technology. The results showed that most MET genes displayed higher expression values at the beginning of both control and N-limiting fermentation, just before the time at which the release of sulphide was observed. MET genes were downregulated when yeast stopped growing which could associate M…
“Framboisé” spoilage in French ciders: Zymomonas mobilis implication and characterization
2006
Abstract Biodiversity of 17 Zymomonas mobilis strains isolated from French “framboise” ciders from 7 different geographical areas of France was analysed using random amplified polymorphic DNA (RAPD) and 6 different strain fingerprints were observed. One of the fingerprints was identical for 10 of the 17 cases. No correlation between geographical origin and strain fingerprint was observed. In parallel, the cider-making process was followed from the orchard to the final product for Z. mobilis presence. Detection of the bacterium only occurred during the fermentation process. The French isolate, strain AN0101, recently proposed as a novel subspecies ( Z. mobilis subsp. francensis ) was charact…
Validation of Using Smartphone Built-In Accelerometers to Estimate the Active Energy Expenditures of Full-Time Manual Wheelchair Users with Spinal Co…
2021
[EN] This study aimed to investigate the validity of using built-in smartphone accelerometers to estimate the active energy expenditures of full-time manual wheelchair users with spinal cord injury (SCI). Twenty participants with complete SCI completed 10 5-min daily activities that involved the upper limbs, during which their oxygen consumption and upper limb activity were registered using a portable gas analyzer and a smartphone (placed on the non-dominant arm), respectively. Time series of 1-min averaged oxygen consumption and 55 accelerometer variables (13 variables for each of the four axes and three additional variables for the correlations between axes) were used to estimate three mu…
Impact of COVID-19 on the self-reported physical activity of people with complete thoracic spinal cord injury full-time manual wheelchair users
2021
Coronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Activitat física; Lesió medul·lar Coronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Actividad física; Lesión de la médula espinal Coronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Physical activity; Spinal cord injury Context The emergence of COVID-19 caused a new public health crisis, leading to major changes in daily life routines, often including physical activity (PA) levels. The main goal of this study was to analyze the differences in self-reported physical activity of people with complete spinal cord injuries between the time prior to the COVID-19 lockdown and the lockdown period itself. Methods A sample of 20 participants with complete thoracic spi…
Digestion of bamboo compared to grass and lucerne in a small hindgut fermenting herbivore, the guinea pig (Cavia porcellus)
2022
Bamboo is an enigmatic forage, representing a niche food for pandas and bamboo lemurs. Bamboo might not represent a suitable forage for herbivores relying on fermentative digestion, potentially due to its low fermentability. To test this hypothesis, guinea pigs (n = 36) were used as model species and fed ad libitum with one of three forages (bamboo, lucerne, or timothy grass) in a fresh or dried state, with six individuals per group, for 3 weeks. The nutrient composition and in vitro fermentation profile of bamboo displayed low fermentation potential, i.e. high lignin and silica levels together with a gas production (Hohenheim gas test) at 12 h of only 36% of that of lucerne and grass. Alth…
2-feniletanola biosintēze ar netradicionālo raugu Kluyveromyces marxianus
2016
Bakalaura darbā mērķis bija pārbaudīt dažādu Kluyveromyces marxianus celmu un fermentācijas apstākļu (L-fenilalanīna, temperatūras, aerācijas) ietekmi uz 2-feniletanola producēšanu. Darbā tika konstatēts, ka L-fenilalanīna pievienošana barotnei būtiski ietekmē 2-feniletanola iznākumu. Tika noteikts, ka optimālie apstākļi 2-feniletanola producēšanai ir glikozes barotne ar 1% L-fenilalanīnu, 150 rpm aerācija un +30°C temperatūra. No darbā pētītajiem pieciem celmiem optimālais 2-feniletanola producēšanai ir K. marxianus DSM 5422, to audzējot uz 10% glikozes barotnes ar 1% L-fenilalanīnu pie +30°C ar 150 rpm aerāciju. Tika noteikts, ka K. marxianus celmi DSM 5422, DSM 5418 un DSM 4906 spēj izma…