Highlight on the problems generated by p-coumaric acid analysis in fermentations

p-Coumaric acid is a natural hydroxycinnamic acid existing in grapes and wine. It is the precursor of the 4-ethylphenol molecule through the bioconversion reaction by Brettanomyces yeast. Chromatographic methods are the most common techniques to detect p-coumaric acid. It is known that this acid is highly unstable in analysis and fermentation experiments. This paper highlights the problems occurring in p-coumaric acid analysis in wine fermentation conditions when studying its bioconversion. First, it was shown that p-coumaric acid was unstable at elevated temperature. On the other hand, it was found that in our experimental conditions p-coumaric acid reacted with ethanol. This work revealed also that the p-coumaric acid is partially adsorbed on Brettanomyces yeast, certainly on cell walls. Because of these phenomena the quantity of p-coumaric acid which can participate to the bioconversion into ethylphenol decreases

Calculation of the C3A Percentage in High Sulfur Clinker

The aim of this paper is to clarify the influence of the clinker SO3 on the amount of C3A. The calculation of the cement phases percentages is based on the research work, Calculation of the Compounds in Portland Cement, published by Bogue in 1929 .The usage of high sulphur fuels, industrial wastes, and tires changes completely the working condition of Bogue because the assumed phase compositions may change. The results prove that increasing the amount of SO3 in the low alkali clinker decreases the percentages of C3A due to the high incorporation of alumina in the clinker phases mainly C2S and C3S. The correlation is linear till the clinker SO3 reaches the 2%. Over that the influence of the clinker SO3 became undetectable. A new calculation method for the determination of the C3A in the high sulphur and low alkali clinker was proposed

Differentiation between Aspergillus flavus and Aspergillus parasiticus from Pure Culture and Aflatoxin-Contaminated Grapes Using PCR-RFLP Analysis of aflR-aflJ Intergenic Spacer

Aflatoxins (AFs) represent the most important single mycotoxin-related food safety problem in developed and developing countries as they have adverse effects on human and animal health. They are produced mainly by Aspergillus flavus and A. parasiticus. Both species have different aflatoxinogenic profile. In order to distinguish between A. flavus and A. parasiticus, gene-specific primers were designed to target the intergenic spacer (IGS) for the AF biosynthesis genes, aflJ and aflR. Polymerase chain reaction (PCR) products were subjected to restriction endonuclease analysis using BglII to look for restriction fragment length polymorphisms (RFLPs). Our result showed that both species displayed different PCR-based RFLP (PCR-RFLP) profile. PCR products from A. flavus cleaved into 3 fragments of 362, 210, and 102 bp. However, there is only one restriction site for this enzyme in the sequence of A. parasiticus that produced only 2 fragments of 363 and 311 bp. The method was successfully applied to contaminated grapes samples. This approach of differentiating these 2 species would be simpler, less costly, and quicker than conventional sequencing of PCR products and/or morphological identification

Health Care Waste generation rates and patterns: The case of Lebanon

The objective of this study is to analyze Infectious Health Care Waste generation rates and patterns in Lebanon. Therefore, the quantities generated during five years by 57 hospitals from a total of 163 in the country have been analyzed. The seasonal evolution of Infectious Health Care Waste production and the evolution of the evaluation of the trends over years have been studied. Besides, the generation per capita have been estimated and compared to other countries. The variance between categories and the correlation between number of beds and Infectious Health Care Waste generation have been analyzed. The obtained results showed that the large private hospitals (over 200 beds) are characterized by their high generation rate: an average of 2.45 kg per occupied bed^-1 day^-1, whereas the average generation rate for other categories is 0.94 kg per occupied bed^-1 day^-1. The weighted mean is 1.14 per occupied kg bed^-1 day^-1. Small public hospitals (i.e. less than 100 beds) have the smallest standard deviation: 0.13, whereas large private hospitals (i.e. over than 200 beds) have the highest standard deviation: 0.40. Infectious Health Care Waste generation has been estimated to 1.42 kg/capita/year. The correlation between the numbers of hospitals beds in hospitals and the generation rate per bed is weak. The correlation between Infectious Health Care Waste generation per day and beds number is stronger. The total quantity produced by hospitals has increased over the five past years. These results suggest that the quantities of medical waste are not well controlled, and that hospitals have a defective monitoring management system of their waste. Annual peaks are observed in June, July, and December. Thus, this study, for the first time in Lebanon, has provided information on the infectious waste generation, allowing benchmarking between hospitals and between countrie

Analysis of the effectiveness of a cereal milling by product monocomponent medium for the low cost production of Bacillus thuringiensis

Bacillus thuringiensis is a facultative anaerobe, gram positive, spore forming bacterium. The biotechnological importance of this bacterium resides in its ability to produce, during sporulation, crystal proteins known as delta-endotoxins which express specific insecticidal activity. At industrial scale, the culture media represents an important part of B. thuringiensis based biopesticides production cost. According to the literature, different agro-industrial residues and byproducts were used as sources of proteins in order to reduce the cost of B. thuringiensis culture medium, but carbohydrates (glucose, starch or molasses) and/or mineral sources were added. In this work, a cereal milling by-product (CMB) as a monocomponent medium was investigated and compared to synthetic mediums in terms of delta-endotoxin yield and productivity in submerged fermentation of different strains of B. thuringiensis. The CMB was shown efficient to be used as a complete substrate (source of proteins, carbohydrates and minerals) for B. thuringiensis production. The optimal CMB ratio in the culture medium was found to be 6% in shake flasks experiments. The consumption of the CMB sugars by the bacteria was analyzed. Production of the bio-insecticide in lab-bioreactor in controlled conditions was equally performed to give basic elements for extrapolation in industrial conditions

Influence de l'étape de croissance et de la quantité de brettanomyces bruxellensis sur la production d'éthyl-phenols

Influence de l'étape de croissance et de la quantité de brettanomyces bruxellensis sur la production d'éthyl-phenol

Indicators of Sustainable Development for Health Care Waste Treatment Industry

Sustainable development is more and more considered as a key parameter and a driving strategy for sustainable performance. Today, numerous organizations develop their own performance indicators as no standard set of performance indicators could be generalized as meaningful in terms of sustainability performance. Particularly, the context of developing countries, where the concept of sustainability is not well diffused yet and where economic difficulties and constraints result most of the times in underestimation of environmental and social considerations, requires specifically adapted indicators. Specially, the sector of health care waste management lacks of sustainability indicators. This sector ensures the treatment, before disposal, of hazardous health care waste generated by health care centers (hospitals, clinics, and others). The evaluation system is designed for monitoring the pace of gaining sustainability within this sector. The objective of this article is to propose a sustainability evaluation system adapted to the needs and situation of developing countries, based on meaningful, practical, easily measurable and applicable indicators for the Infectious Health Care Waste (IHCW) Treatment sector

Evaluation of a cereal milling by-product for the low cost production of Bacillus thuringiensis kurstaki in submerged fermentation

With the idea of finding a cheap medium for the mass production of Bacillus thuringiensis (Bt), a cereal milling by product (CMB) was evaluated and was shown efficient to be used as a source of carbohydrates, proteins and minerals for the production of δ-endotoxins in submerged fermentation of a new strain of Bacillus thuringiensis kurstaki “Lip”. The results obtained in 1000 mL shake flasks experiments showed that the toxin proteins concentration produced in the 6% (w/v) CMB medium was 2.4 fold and 1.54 fold greater than the values reached in the Anderson medium and in a standard semi synthetic medium respectively, while there was no significant difference between the cell, spore and crystal counts or between the protein profiles of the “Lip” spore/crystal complex obtained in the three mediums. Considering all three factors, relative yield, productivity and cost, the use of the CMB mono-component medium was proved much more economical for an industrial production of “Lip” than the references mediums. Moreover, the suitability of the medium for large scale production of Bt based bio insecticide was evidenced in a 5 L lab bioreactor

Evaluation du risque Brettanomyces dans le vignoble libanais et étude cinétique de la bioconversion de l'acide p-coumarique en 4-éthylphénol

Les altérations sensorielles des vins dues à la présence des levures du genre Brettanomyces se caractérisent par une augmentation de la teneur en phénols volatils tel que le 4-éthylphénol. Le premier objectif de ce travail était de faire un état des lieux sur le risque éthylphénol au Liban en s'intéressant à la présence d'un précurseur (acide p-coumarique), du microorganisme responsable (Brettanomyces) et du produit final (4-éthylphénol) dans les vins élaborés dans ce pays. Une forte hétérogénéité de concentrations en acide p-coumarique a été observée avec des valeurs variant de 0 à 31,4 mg.L-1. Des niveaux importants de 4-éthylphénols de l'ordre de 1,367 mg.L-1 ont été détectés sur certains vins. Un dépistage du contaminant microbien a permis de confirmer pour la première fois la présence de Brettanomyces au Liban, les proportions restant toutefois assez faibles (3 % des échantillons testés). Une étude génétique a caractérisé les souches retenues qui se sont montrées diverses au sein de l'espèce. Le travail a porté ensuite sur l'analyse cinétique des étapes réactionnelles constituant le processus enzymatique de la bioconversion des substrats acide p-coumarique et 4-vinlphénol en 4-éthylphénol pour 5 souches de Brettanomyces bruxellensis d'origines libanaises et françaises. La variabilité entre les souches s'est exprimée aux niveaux génétique et cinétique. Des profils hétérogènes de bioréaction ont été mis en évidence en fonction de la nature des souches. L'analyse du bilan-matière a révélé l'existence probable de phénomènes d'adsorption sur les parois des Brettanomyces qui sont souche-dépendants. La dernière partie a été consacrée à l'évaluation du lien entre quantité de biomasse et production de 4-éthylphénol ainsi qu'à l'influence de quelques paramètres environnementaux (pH, source d'ammonium et milieu de culture) sur la cinétique réactionnelle.Wine sensory alterations due to the presence of Brettanomyces yeasts are characterized by an increased content of volatile phenols such as 4-ethylphenol. The first aim of this work was to make an inventory of the "ethylphenol" risks in Lebanon by focusing on the presence of one precursor (p-coumaric acid), the microorganism provoking these risks (Brettanomyces) and the final product (4-ethylphenol) in wines produced in this country. High heterogeneity of p-coumaric acid concentration was observed with values ranging from 0 to 31,4 mg.L-1. Significant levels of 4-ethylphenols of about 1,367 mg L-1 have been detected in some wines. Screening of microbial contaminants confirmed the presence of Brettanomyces for the first time in Lebanon, with proportions remaining relatively low (3 % of samples tested). A genetic study has characterized the selected strains which are shown to be various within the species. The second objective of this study was the kinetic analysis of the reaction steps constituting the bioconversion enzymatic process of both substrates p-coumaric acid and 4-vinlphenol into 4-ethylphenol for 5 strains of Brettanomyces bruxellensis of different origins (Lebanon and France). Variability between strains was expressed at both levels, genetic and kinetic. Heterogeneous bioreaction profiles were identified according to strain's nature. The mass balance analysis revealed the possible existence of adsorption phenomena on the cell walls of Brettanomyces which are strain-dependent. The last part was devoted to the evaluation of the relationship between biomass concentration and production of 4-ethylphenol as well as the influence of some environmental parameters (pH, ammonium source and culture medium) on the reaction's kinetic.TOULOUSE-INP (315552154) / SudocSudocFranceF

The effect of aeration conditions, characterized by the volumetric mass transfer coefficient KLa, on the fermentation kinetics of Bacillus thuringiensis kurstaki

The aeration is a key factor for Bacillus thuringiensis growth, sporulation and δ-endotoxins production. The objective of our work was to study the effect of aeration on the fermentation kinetics of Bacillus thuringiensis kurstaki (Btk), cultivated in a cereal milling byproduct (CMB) mono-component medium, in order to improve the δ-endotoxins productivity. Aeration conditions were systematically characterized by the volumetric mass transfer coefficient KLa. In the 6% CMB culture medium, different values of the maximal specific oxygen uptake rate were obtained at different values of KLa. For KLa of 7.2 h−1, the growth was inhibited and the sporulation was defective. There was a linear increase of the average specific growth rate and faster sporulation and liberation of spores and δ-endotoxins crystals when KLa was increased between 13.3 h−1 and 65.5 h−1. Similar kinetic was observed in cultures performed at KLa equal to 65.5 h−1 and 106.2 h−1. The highest toxins productivity of 96.1 mg L−1 h−1 was obtained in the 9% CMB culture medium for KLa of 102 h−1. It was possible to track the evolution of the bacterial cells between vegetative growth, sporulation and liberation of mature spores by following the variation of the CO2 percent in the effluent gas