eKhSACIR інституційному репозитарії Харківської державної академії культури
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Meta-analysis of the efficiency of metabolisable protein utilization in dairy cows and goats
No full textInternational audienc
Towards the identification of gene candiates for maternal effects on weaning weight in six beef cattle breeds
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Impact of antibiotherapy and rapidly fermentable fiber in the diet of young rabbit assessed by transcriptomic approaches: preliminary results
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Advances in food characterization and contaminant determination through hyphenated mass spectrometry
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Agriculture biologique et protection de la qualité de l’eau : Cohérence des politiques publiques et dynamiques d’agriculteurs
No full textactes en lineNational audienceIn the light of the water policy, which is struggling to produce tangible results in terms of water resourcesquality, strong political signals have been sent following the Grenelle Environment Forum in 2009.Protecting water catchment areas (WCA) from agricultural diffuse pollutions has become a set objectivefor local authorities and catchment managers. Setting up water resource protection approaches impliesto initiate changes in agricultural practices and systems. Organic farming has been gradually recognizedas a relevant solution with regard to the drinking water issue and recent regulatory instruments conside that organic farming conversions may be preferentially located in WCAs. In this article we reviewed thefunctioning and the progress of WCA approaches, whose methodology was defined by the stateauthorities. We analysed the place reserved for organic farming in agricultural action programs, thevarious constraints affecting dynamics of organic conversions and determinants of success. Theseelements provide a critical understanding on the implementation of these public policies and the leversfor combining organic agriculture and issues related to protection of water resources.Face à une politique de l’eau qui peine à produire des résultats tangibles en termes de qualité de la ressource en eau, des signaux politiques forts ont été émis à la suite du Grenelle de l’environnement en 2009. Protéger les aires d’alimentation de captages (AAC) vis à vis des pollutions diffuses d’origine agricole est ainsi devenu un objectif fixé pour les collectivités territoriales et les gestionnaires de captages. Mettre en place des démarches de protection de la ressource implique d’initier des changements de pratiques agricoles et de systèmes. L’agriculture biologique (AB) a été progressivement reconnue comme une solution pertinente au regard de l’enjeu eau potable et les dispositifs réglementaires récents considèrent que les conversions en AB pourraient être préférentiellement localisées au niveau des AAC. Dans cet article, nous faisons un bilan du déroulement et de l’avancement des démarches AAC, démarches de projets dont la méthodologie a été définie par les instances de l’Etat. Nous analysons la place de l’AB au sein des programmes d’actions issus de ces démarches AAC, les diverses contraintes agissant sur les dynamiques de conversions en bio et les déterminants des réussites. Ces éléments portent un regard critique sur la mise en œuvre de ces politiques publiques et sur les leviers pour combiner agriculture biologique et enjeux liés à la protection de la ressource en eau
The role of sulfur nutrition in the pea response to water deficit
No full textBAP GEAPSINational audiencePea (Pisum sativum L.) produces seeds rich in proteins for human and animal nutrition and its cultivation enriches the soils in nitrogen, thus decreasing the need for nitrogen fertilization. Increasing pea cultivation and productivity is an agroecological challenge which requires to improve its tolerance to environmental stresses. Water deficit and the lack of sulfur in soils are two abiotic stresses that interact in the current context of climate change and low-input practices. Sulfur metabolites are known to play a protective role against many stresses but their interaction with the plant response to drought remains to be studied. A system biology approach will be used to study the influence of sulfur nutrition on gene and protein networks associated with the response of pea leaves to water stress during the reproductive phase. This approach will provide metabolic regulation models connecting sulfur nutrition to the water stress response. The integration of other data (e.g., physiological, yield components) will reveal regulatory factors potentially responsible for the physiological variations observed and/or for the modifications of agronomic traits under these environmental constraints. In addition to provide a better understanding of the role of sulfur in the plant’s response to drought, the project will lead to the identification of gene and protein candidates for improving the tolerance of pea to climate change and low-input practices
Effects of DGAT1 K232A polymorphism and milking frequency on milk composition and spontaneous lipolysis in dairy cows
No full textInternational audienceMilk spontaneous lipolysis (SL) of milk triglycerides is induced by the lipoprotein lipase, a milk native enzyme, and leads to an accumulation of partial glycerides and free fatty acids that are responsible for the deterioration of the taste of milk products. The gene coding for diacylglycerol acyltransferase 1 (DGAT1), an enzyme implicated in triglycerides synthesis, has an important polymorphic site at the K232A locus. This gene is well known to modulate milk composition. No data are available on the effects of DGAT1 on SL. Thus, a trial was carried out to evaluate the effects of DGAT1 K232A polymorphism on milk SL upon milking frequency variations [once- (ODM) and twice-daily milking (TDM)]. Twenty-one cows were divided into 3 groups according their DGAT1 K232A genotype: 8 cows had the KK genotype of DGAT1 (KK cows), 8 had the KA genotype (KA cows), and 5 had the AA genotype (AA cows). The trial consisted in 3 successive periods: 3 wk of TDM, 3 of ODM, and 4 of TDM. Samples were collected for fat and protein contents, SL, fatty acid, and protein profiles determinations. The KK cows presented higher fat and protein contents, lower milk production, and higher κ-casein percentage. No significant difference in fatty acid composition was noted between groups. The SL was twice as high for KK cows in TDM situations (1.13 vs. 0.59 and 0.63 mEq/100 g of fat, respectively, for KK, KA, and AA cows during the first period of TDM, and 0.46 vs. 0.25 and 0.21 mEq/100 g of fat, respectively, for KK, KA, and AA during the second period of TDM). The SL remained sharply lower in TDM2 than in TDM1. During ODM, no difference in SL was found between groups and SL remained below 0.2 mEq/100 g of fat. These results demonstrate the existence of a correlation between DGAT1 genotypes and spontaneous lipolysis, in interaction with an environmental factor, milking frequency, although it has not been possible to clarify the causal mechanism at this stage
Evaluation of the biosafety of recombinant lactic acid bacteria designed to prevent and to treat colitis
No full textInflammatory Bowel Diseases or IBD affect the gastrointestinal tract and are characterized by recurrent inflammation that requires lifelong therapies. Probiotics such as lactic acid bacteria (LAB) have been proposed to complement current treatment protocols for these patients; however, their characteristics are strain dependent. In this regard certain novel characteristics are only possible through the genetic modification of these beneficial microorganisms. Different delivery systems, such as protein delivery of anti-oxidant enzymes and the anti-inflammatory cytokines such as IL-10 and DNA delivery have been shown to be effective for preventing and treating IBD in animal models. In this study, the safety of the recombinant LAB (recLAB) Streptococcus thermophilus (S.) CRL807:CAT, S. thermophilus CRL807: SOD, Lactococcus (L.) lactis NCDO2118 pXILCYT:IL-10, L. lactis MG1363 pValac:IL-10 and L. lactis MG1363 pGroESL:IL-10 with proven beneficial effects were compared to their progenitor strains S. thermophilus CRL807, L. lactis NCDO2118 or L. lactis MG1363. The prolonged administration of genetically modified strains evaluated in the present work showed that they were just as safe as the administration of the native strains from which they derive as demonstrated by normal animal growth and relative organ weights, absence of microbial translocation, altered blood parameters and modifications of intestinal histology. The results show the potential use of these recLAB in future therapeutic formulations; however, the use of modern bio-containment systems is required for the future acceptance of these recLAB by the medical community and patients suffering IBD
High-throughput fermentation screening for the yeast Yarrowia lipolytica with real-time monitoring of biomass and lipid production
No full textInternational audienceBackground : Because the model yeast Yarrowia lipolytica can synthesize and store lipids in quantities up to 20 % of its dry weight, it is a promising microorganism for oil production at an industrial scale. Typically, optimization of the lipid production process is performed in the laboratory and later scaled up for industrial production. However, the scale-up process can be complicated by genetic modifications that are optimized for one set of growing conditions can confer a less-than-optimal phenotype in a different environment. To address this issue, small cultivation systems have been developed that mimic the conditions in benchtop bioreactors. In this work, we used one such microbioreactor system, the BioLector, to develop high-throughput fermentation procedures that optimize growth and lipid accumulation in Y. lipolytica. Using this system, we were able to monitor lipid and biomass production in real time throughout the culture duration. Results : The BioLector can monitor the growth of Y. lipolytica in real time by evaluating scattered light; this produced accurate measurements until cultures reached an equivalent of OD600nm = 115 and a cell dry weight of 100 g L−1. In addition, a lipid-specific fluorescent probe was applied which reliably monitored lipid production up to a concentration of 12 g L−1. Through screening various growing conditions, we determined that a carbon/nitrogen ratio of 35 was the most efficient for lipid production. Further screening showed that ammonium chloride and glycerol were the most valuable nitrogen and carbon sources, respectively, for growth and lipid production. Moreover, a carbon concentration above 1 M appeared to impair growth and lipid accumulation. Finally, we used these optimized conditions to screen engineered strains of Y. lipolytica with high lipid-accumulation capability. The growth and lipid content of the strains cultivated in the BioLector were compared to those grown in benchtop bioreactors. Conclusion : To our knowledge, this is the first time that the BioLector has been used to track lipid production in real time and to monitor the growth of Y. lipolytica. The present study also showed the efficacy of the BioLector in screening growing conditions and engineered strains prior to scale-up. The method described here could be applied to other oleaginous microorganisms
Increased Cost of Motor Activity and Heat Transfer between Non-Shivering Thermogenesis, Motor Activity, and Thermic Effect of Feeding in Mice Housed at Room Temperature – Implications in Pre-Clinical Studies
No full textInternational audienceThe components of energy expenditure, total metabolic rate (TMR), resting metabolic rate (RMR), thermogenic response to feeding (TEF), activity, and cost of activity were measured in fed and fasted mice housed at 22 and 30 degrees C. Mice housed at 22 degrees C had more than two times larger TMR and RMR. Mice at 22 degrees C were less active when fasted but more active when fed. Cost of activity was nearly doubled in the fasted and in the fed state. Analysis of the short-term relation between TMR, RMR, and bouts of activity showed that, at 22 degrees C, the bouts of activity induced a decrease in the intensity of RMR that reflected the reduced need for thermal regulation induced by the heat released from muscular contraction. This phenomenon induced a considerable underestimation of TEF and prevented its reliable measurement when mice were housed at 22 degrees C. Correlation between TMR and activity measured across time in individual mice was very strong at both 22 and 30 degrees C, but the correlation measured across mice was much weaker at 30 degrees C and no longer significant at 22 degrees C. We suspect that this phenomenon was due to the fact that RMR is a much more reliable predictor of TMR than activity. RMR is more variable at 22 degrees C than at 30 degrees C because of heat transfers between thermal regulation and heat released by other discontinuous processes, such as activity and TEE Therefore, more noise is introduced into the correlations performed across multiple mice between TMR and activity at 22 degrees C. On the other hand, it should be kept in mind that the doubling of TMR and RMR at 22 degrees C is fueled by an increased non-shivering thermogenesis that can obviously modify how the mouse responds to pharmacological and nutritional challenges. Taken together, these results suggest that in pre-clinical studies, mice should be housed in conditions where thermal regulation is limited as is generally the case in humans. However, the increased sensitivity of mice to small changes in ambient temperature can also be used as a versatile tool to investigate the role of thermal regulation on the energy balance equation in humans