Action of Patulin on Yeast

The action of patulin on Saccharomyces cerevisiae was studied. At weak doses, the drug inhibited growth, but inhibition was transient. After 10 min, syntheses of rRNA, tRNA, and probably mRNA were blocked; this was shown by radioactive precursor incorporation assays and gel electrophoresis of RNAs. After recovery of growth, patulin disappeared from the medium. It seemed that this degradation resulted from the activity of an inducible enzymatic system. Induced cells resisted very high patulin concentrations

Impact du couplage de la déshydratation osmotique et du séchage sur la qualité nutritionnelle de la tomate séchée

Le présent travail vise à évaluer l’effet des paramètres opératoires sur la teneur en cendre, la perte en caroténoïdes totaux et la perte en vitamine C de la tomate au cours des procédés de déshydratation et à modéliser ce phénomène en vue d’en déduire les conditions opératoires optimales. Des modèles prédictifs ont été proposés pour relier les attributs de qualité du produit fini aux différentes variables opératoires de la déshydratation osmotique combinée au séchage. La condition optimale de travail de la combinaison déshydratation osmotique/séchage  appliquée aux tomates est donc l’utilisation d’une concentration de chlorure de sodium de 100 g/l, une température de la solution osmotique  de 30°C, une durée de la déshydratation osmotique de 60 minutes et une température de séchage de 60 °C pour obtenir un produit final avec  une perte en acide ascorbique la plus basse  de 2,29%, une teneur minimale en perte en caroténoïdes totaux de 15,17% et une teneur minimale en cendres de 0,84%

Two rapid assays for screening of patulin biodegradation

Artículo sobre distintos ensayos para comprobar la biodegradación de la patulinaThe mycotoxin patulin is produced by the blue mould pathogen Penicillium expansum in rotting apples during postharvest storage. Patulin is toxic to a wide range of organisms, including humans, animals, fungi and bacteria. Wash water from apple packing and processing houses often harbours patulin and fungal spores, which can contaminate the environment. Ubiquitous epiphytic yeasts, such as Rhodosporidium kratochvilovae strain LS11 which is a biocontrol agent of P. expansum in apples, have the capacity to resist the toxicity of patulin and to biodegrade it. Two non-toxic products are formed. One is desoxypatulinic acid. The aim of the work was to develop rapid, high-throughput bioassays for monitoring patulin degradation in multiple samples. Escherichia coli was highly sensitive to patulin, but insensitive to desoxypatulinic acid. This was utilized to develop a detection test for patulin, replacing time-consuming thin layer chromatography or high-performance liquid chromatography. Two assays for patulin degradation were developed, one in liquid medium and the other in semi-solid medium. Both assays allow the contemporary screening of a large number of samples. The liquid medium assay utilizes 96-well microtiter plates and was optimized for using a minimum of patulin. The semisolid medium assay has the added advantage of slowing down the biodegradation, which allows the study and isolation of transient degradation products. The two assays are complementary and have several areas of utilization, from screening a bank of microorganisms for biodegradation ability to the study of biodegradation pathways

Taenia solium Cysticercosis in the Democratic Republic of Congo: How Does Pork Trade Affect the Transmission of the Parasite?

Taenia solium is a parasite that can affect both humans and pigs, causing important economic losses in pig production and being the main cause of acquired epilepsy in endemic areas. However, the parasite has been neglected in many African countries and particularly in the Democratic Republic of Congo (DRC), where recent data are non-existent. The present study is part of a first initiative to assess whether cysticercosis is actually present in DRC and to estimate its potential economic and public health importance. Focusing our work on porcine cysticercosis, we demonstrated high prevalence figures of active infections in villages in a rural area of DRC and in markets in the city of Kinshasa. Moreover, the intensity of infection was higher in pigs sampled in villages as compared to pigs sampled on urban markets. Preliminary surveys conducted in parallel in both study sites suggest an effect of pork trade on the transmission of the parasite selecting highly infected pigs at village level