The potential of Lactobacillus rhamnosus R for producing exopolysaccharide (EPS) when grown on basal minimum medium supplemented with glucose or lactose was investigated. EPS production by L. rhamnosus R is partially growth associated and about 500 mg of EPS per liter was synthesized with both sugars. ؊1 ). It was clearly shown that the amount of EPS produced declined upon prolonged fermentation. Degradation of EPS in fermentation processes was also assessed by measuring its molecular weights and viscosities. As these reductions might have a negative effect on the yield and viscosifying properties of EPS, it was essential to examine possible causes related to this breakdown. The decrease in viscosities and molecular weights of EPS withdrawn at different cultivation times permitted us to suspect the presence of a depolymerizing enzyme in the fermentation medium. Our study on enzymatic production profiles showed a large spectrum of glycohydrolases (␣-D-glucosidase, ␤-D-glucosidase, ␣-D-galactosidase, ␤-D-galactosidase, ␤-D-glucuronidase, and some traces of ␣-L-rhamnosidase). These enzymes were localized, two of them (␣-D-glucosidase and ␤-D-glucuronidase) were partially purified and characterized. When incubated with EPS, these enzymes were capable of lowering the viscosity of the polymer as well as liberating some reducing sugars. Upon prolonged incubation (27 h), the loss of viscosity was increased up to 33%.Exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) have generated increasing attention among researchers for the last few years. LAB are food-grade organisms, and the EPS that they produce contribute to the specific rheology and texture of fermented milk products. These EPS represent safe additives for novel food formulations and may have applications in nonfood products (8).There exist three important groups of EPSs produced by LAB: (i) ␣-glucans, mainly composed of ␣-1,6-and ␣-1,3-linked glucose residues, namely, dextrans produced by Leuconostoc mesenteroides subsp. mesenteroides and L. mesenteroides subsp. dextranicum and mutans produced by Streptococcus mutans and S. sobrinus; (ii) fructans, mainly composed of ␤-2,6-linked fructose molecules, such as levan produced by S. salivarius; (iii) heteropolysaccharides produced by mesophilic (Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris) and thermophilic (Lactobacillus delbrueckii subsp. bulgaricus, L. helveticus, and S. thermophilus) LAB (5). The EPS produced by Lactobacillus rhamnosus belong to third group (14). The sugar composition of the EPS produced by L. rhamnosus R studied in this work, as determined on the hydrolysate by high-pressure liquid chromatography (HPLC) and by gas chromatography of the alditol acetates, is the following: Rha, 4; Glc, 2; and Gal, 1 (M. R. Van Casteren, personal communication).A considerable variation can be observed in EPS quantifications. The amount of EPS reported varies from 25 to 132 mg/ liter for L. lactis subsp. cremoris (26) Many studies showed a decrease in the total EPS amount when incuba...

Tigris ID-NAT format was significantly more sensitive than cobas s 201 MP-NAT in detecting HCV RNA and HIV RNA dilution panels, but despite the 1:6 dilution factor in s 201 the difference in sensitivity was not significant for some of the HBV genotype panels. Both NAT systems demonstrated acceptable operational performance, but for routine use further improvement in system reliability is desirable.

Over the past decade, our views have considerably evolved with respect to the metabolism of intravenous lipid emulsions and their composition. Substantial progress has been made in understanding the metabolic pathways of emulsion particles and the delivery of their various components (fatty acids and vitamins) to specific tissues or cells. Although soybean long-chain triglycerides represent a valuable source of energy, concerns have been raised about their high content of polyunsaturated fatty acids (mainly n-6 essential fatty acids), which may adversely affect immune functions and antioxidant status. Introduction of medium-chain triglycerides or olive oil to lipid emulsions can largely help bypass these disadvantages. Recently, incorporation of n-3 fatty acids in lipid preparations was suggested to have potential application in several chronic and acute diseases because of their ability to reduce inflammatory and thrombotic responses and cell sensitivity to various stimuli. Hence lipid emulsions should no longer be considered only as a means of providing energy substrates; they also modulate key metabolic functions. Such improved knowledge may lead to optimizing the metabolic care of certain patients.

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