Creativity in Scientific Research: Multidisciplinarity Fosters Depth of Ideas Among Scientists in Electronic "Brainwriting" Groups.

Objective: The aim of this study was to examine the potential benefits of multidisciplinarity among agri-food researchers working in small groups to generate ideas to stimulate innovation in the context of a laboratory project.

Background: Research on the role of multidisciplinarity in scientific research teams remains limited, particularly regarding the generation of ideas to innovate in a real laboratory project, and on a task with a real challenge for innovation.

Method: Researchers and agri-food research staff were assigned to small groups of either multidisciplinary or unidisciplinary composition to produce ideas on a cross-cutting theme for an innovative laboratory project using an electronic "brainwriting" application.

Bacterial Colonies in Solid Media and Foods: A Review on Their Growth and Interactions with the Micro-Environment.

Bacteria, either indigenous or added, are immobilized in solid foods where they grow as colonies. Since the 80's, relatively few research groups have explored the implications of bacteria growing as colonies and mostly focused on pathogens in large colonies on agar/gelatine media. It is only recently that high resolution imaging techniques and biophysical characterization techniques increased the understanding of the growth of bacterial colonies, for different sizes of colonies, at the microscopic level and even down to the molecular level.

Colonial vs. planktonic type of growth: mathematical modeling of microbial dynamics on surfaces and in liquid, semi-liquid and solid foods.

Predictive models are mathematical expressions that describe the growth, survival, inactivation, or biochemical processes of foodborne bacteria. During processing of contaminated raw materials and food preparation, bacteria are entrapped into the food residues, potentially transferred to the equipment surfaces (abiotic or inert surfaces) or cross-contaminate other foods (biotic surfaces). Growth of bacterial cells can either occur planktonically in liquid or immobilized as colonies.

Spatial Distribution of Lactococcus lactis Colonies Modulates the Production of Major Metabolites during the Ripening of a Model Cheese.

In cheese, lactic acid bacteria are immobilized at the coagulation step and grow as colonies. The spatial distribution of bacterial colonies is characterized by the size and number of colonies for a given bacterial population within cheese. Our objective was to demonstrate that different spatial distributions, which lead to differences in the exchange surface between the colonies and the cheese matrix, can influence the ripening process.

Diffusion of solutes inside bacterial colonies immobilized in model cheese depends on their physicochemical properties: a time-lapse microscopy study.

During cheese processing and ripening, bacteria develop as colonies. Substrates and metabolites must then diffuse either from or into the colonies. Exploring how the inner cells of the colony access the substrates or get rid of the products leads to study the diffusion of solutes inside bacterial colonies immobilized in cheese.

Early adaptation to oxygen is key to the industrially important traits of Lactococcus lactis ssp. cremoris during milk fermentation.

Background: Lactococcus lactis is the most used species in the dairy industry. Its ability to adapt to technological stresses, such as oxidative stress encountered during stirring in the first stages of the cheese-making process, is a key factor to measure its technological performance. This study aimed to understand the response to oxidative stress of Lactococcus lactis subsp.

Contribution of Lactococcus lactis reducing properties to the downregulation of a major virulence regulator in Staphylococcus aureus, the agr system.

Staphylococcus aureus is a major cause of food poisoning outbreaks associated with dairy products, because of the ingestion of preformed enterotoxins. The biocontrol of S. aureus using lactic acid bacteria (LAB) offers a promising opportunity to fight this pathogen while respecting the product ecosystem.

Microgradients of pH do not occur around Lactococcus colonies in a model cheese.

Lactococci inoculated into cheese grow as colonies producing lactic acid. The pH microgradients were investigated around colonies in a complex food such as cheese. The results, obtained using a nondestructive technique, demonstrated that pH microgradients did not occur regardless of the acidification kinetics and the size of the colony.

First mass spectrometry metabolic fingerprinting of bacterial metabolism in a model cheese.

Metabolic fingerprinting is an untargeted approach which has not yet been undertaken to investigate cheese. This study is a proof of concept, concerning the ability of mass spectrometry (MS) metabolic fingerprinting to investigate modifications induced by bacterial metabolism in cheese over time. An ultrafiltrated milk concentrate was used to manufacture model cheeses inoculated with Lactococcus lactis LD61.

Porosity of Lactococcus lactis subsp. lactis LD61 colonies immobilised in model cheese.

During cheese ripening, micro-organisms grow as immobilised colonies, metabolising substrates present in the matrix which generate products triggered by enzymatic reactions. Local limitation rates of diffusion, either in the matrix or within the bacterial colonies, can be responsible for modulation in the metabolic and enzymatic activities of micro-organisms during ripening. How bacterial colonies immobilised in cheese are porous to these diffusing solutes has never been explored.

Molecular characterization and structural instability of the industrially important composite metabolic plasmid pLP712.

The widely used plasmid-free Lactococcus lactis strain MG1363 was derived from the industrial dairy starter strain NCDO712. This strain carries a 55.39 kb plasmid encoding genes for lactose catabolism and a serine proteinase involved in casein degradation.

The efficacy of nisin can drastically vary when produced in situ in model cheeses.

Nisin, a bacteriocin produced by strains of Lactococcus lactis, has a broad inhibitory effect against Gram-positive bacteria. This study investigated the efficacy of nisin Z against Lactobacillus sakei when produced by a nisin-producing strain L. lactis in model cheeses manufactured with ultrafiltrated milk.

First assessment of diffusion coefficients in model cheese by fluorescence recovery after photobleaching (FRAP).

Mass transfer of solutes like salt, moisture and metabolites, is very important for the final quality of cheese, through the control of the brining and ripening processes. Numerous studies have reported salt and water transfer properties in cheese, but few have dealt with other solutes. Moreover, most diffusion coefficients have been obtained by macroscopic and destructive methods.

Nisin quantification by ELISA allows the modeling of its apparent diffusion coefficient in model cheeses.

The diffusion of small solutes in cheese is of key importance for most enzymatic reactions involved in the ripening process. However, only a limited amount of data is available on salt diffusion and practically none on peptide diffusion. Nisin, a bacteriocin peptide, migrated in model cheeses made from ultrafiltered (UF) retentate.

Spatial distribution of bacterial colonies in a model cheese.

In most ripened cheeses, bacteria are responsible for the ripening process. Immobilized in the cheese matrix, they grow as colonies. Therefore, their distribution as well as the distance between them are of major importance for ripening steps since metabolites diffuse within the cheese matrix.

Dynamic analysis of the Lactococcus lactis transcriptome in cheeses made from milk concentrated by ultrafiltration reveals multiple strategies of adaptation to stresses.

Lactococcus lactis is used extensively for the production of various cheeses. At every stage of cheese fabrication, L. lactis has to face several stress-generating conditions that result from its own modification of the environment as well as externally imposed conditions.

Milk acidification by Lactococcus lactis is improved by decreasing the level of dissolved oxygen rather than decreasing redox potential in the milk prior to inoculation.

Although redox potential is very rarely taken into account in food fermentation it could be as influential as pH on bacterial activities. Lactococcus lactis is already known to exhibit a powerful reducing activity in milk but its reduction activity was shown to occur prior to its acidification activity with a potential interaction between these two lactococcal activities. Therefore, acidification lag-type phase could be shortened by decreasing the redox potential of milk before inoculation.

Characterization of the heat treatment undergone by milk using two inhibition ELISAs for quantification of native and heat denatured alpha-lactalbumin.

Dairy industries are interested to know the heat treatment undergone by milk for controlling the quality of drinking milks or to control their heating systems. The purpose of this work was to develop a specific and sensitive technique for classification of the heat treatment a milk has been submitted to, without disposing of the original raw milk. For this purpose, alpha-lactalbumin was chosen as a bioindicator of heat treatment, and monoclonal antibodies specific for its native or heat-denatured form were raised and used in two inhibition ELISAs.

[Prevalence of latex allergy among personnel at a hospital].

The aim of this study was to compile a register of all the employees of a University Hospital Centre who complained of dermatosis of the hands due to latex. Recruitment was made by their spontaneous presentation in the service of the Workers Doctor (Médecine de Travail). The prevalence of clinical signs of contact eczema or professional urticaria is 2.

Ontogeny of taurocholate accumulation in the terminal ileal mucosal cells of young chicks.

The everted, ileal ring technique of Little and Lester was utilized to study taurocholate accumulation against a concentration gradient in the terminal ileal mucosal cells of chicks from hatch to 6 wk of age. The chicks had low levels of taurocholate accumulation at hatch. A three- to fourfold increase in accumulation was observed at Day 3 posthatch, but taurocholate returned to baseline levels within 2 days.