Effects of several environmental factors on the anti-Listeria monocytogenes activity of an essential oil of Picea excelsa.

The effects of several environmental factors on the anti-Listeria monocytogenes activity of an essential oil of Picea excelsa were explored by determination of active concentrations using two methods and with survival curves. In trial conditions, the serovars 1/2c and 4b behaved similarly. A dose of 0.2-0.3% (v/v) of essential oil was bactericidal for 10(5)-10(7) cells contained in 1 ml of Tryptone Soy Broth Yeast Extract at pH 6 and 7 incubated at 13 and 37 degrees C and of medium supplemented with levan. Introduction of sodium caseinate, agar or fat into the test medium and use of a cheese medium decreased the bactericidal effects of the essential oil. Basic pH, addition of NaCl or use of Tryptone Soy Broth and saline solution increased its antilisterial activity. Serovar 1/2c survival curves exhibited an exponential death rate followed by a tailing effect in the presence of the minimal bactericidal concentration of the essential oil. A three log10 reduction of cell viability was obtained within 100 min in Tryptone Soy Broth Yeast Extract, within longer exposure in media supplemented with NaCl or at basic pH.

Removal of hydrocarbons from wastewater using treated bark.

This paper explores the possibility of removing hydrocarbons (HCs) and trace elements from synthetic and industrial effluents using treated bark as biosorbent. Coniferous bark was treated either chemically (Tc) or biologically (Tb) to eliminate soluble organic compounds of bark. The removal efficiency (RE) of the HCs from a synthetic oil-water mixture containing spent diesel motor oil exceeds 95% using 2 g/L of treated bark mixed with a synthetic oil-water mixture containing 2 g/L of spent oil. Under these conditions, the retention capacity (RC) was approximately 1 g HC/g dry substrate. The sorption reaction seems to be quasi-instantaneous, and the retention capacity of spent oil on treated bark increases as the temperature augments. This implies that the retention mechanism is related to the capillary action. Results of Fourier transform infrared (FTIR) spectroscopy indicate that spent oil is mainly composed of alkanes. They also suggest that no chemical bonds between Tc and spent oil were established. Measurement of the surface tension of spent oil and the wetting index of the bark suggests that only spent oil will be retained by the substrate. Treatment of an industrial effluent containing 14.4 g/L of total HCs was performed using Tc. It was possible to remove 97% of HCs and retain some trace elements such as Al, Ca, Fe, Mg, S, and so on.

One-Step Purification of a Lipolytic Enzyme from Bacillus pumilus by Mild Hydrophobic Interaction Chromatography on Polyoxyalkylene Glycol-Bound Sepharose 6B.

An esterase from Bacillus pumilus was obtained in a highly purified form, starting from a crude extract, by a new chromatographic technique requiring no detergent during the elution step. The stationary phase involved was mildly hydrophobic and was prepared by covalent immobilization of a polyoxyalkylene glycol onto Sepharose 6B.

[Nutritional rehabilitation and evaluation of the nutritional state. Validity of anthropometric measures for following, in hospitalized patients, the course of nutritional status and of body compartments during nutritional recovery]. / Réanimation alimentaire et evaluation de l'etat nutritionnel. Validité des mesures anthropometriques pour suivre, chez les malades hospitalisés, l'evolution de l'etat nutritionnel et des compartiments corporels durant le rattrapage nutritionnel.

A population suffering from a serious form of malnutrition was examined. The effectiveness of nutritional rehabilitation is demonstrated by the statistically significant changes observed in clinical and laboratory indicators. Several anthropometric measurements related to nutritional status are also compared with total body potassium (TBK) in patients with a positive nitrogen balance during the process of nutritional rehabilitation. It is concluded that weight (W), arm circumference (AC), middle arm muscle circumference (MAMC) and skinfold thickness (ST) measures are useful, and sufficiently accurate and precise to follow the evolution of nutritional status and body compartments.

[Data on the quantity and quality of lipolytic bacteria in products with a meat base]. / Données sur la quantité et la qualité des bactéries lipolytiques dans des produits à base de viande.

The numbers of lipolytic bacteria and their proportion, relatively to total mesophilic aerobic bacteria, were determined in 65 samples. Other analyses: psychrotrophic bacteria, coliform bacteria, Escherichia coli, fecal streptococci, and enterotoxinogenic staphylococci were also made. The less modified products generally contained a low number of lipolytic bacteria. 101 isolates very lipolytic were obtained, 81 of which were Gram + bacteria and 20 were Gram --. It is hypothesized that in pork-meat preparations, Gram + bacteria, especially Bacillus and fecal steptococci, have a lipolytic action of greater importance than it is generally assumed.