Synthetic dyes decolourisation by white-rot fungi: Development of original microtitre plate method and screening

A microtitre plate-based method was developed for a fast screening of numerous fungal strains for their ability to decolourise textile dyes. In 3 days, this method allowed to estimate significant fungal decolourisation capability by measuring the absorbance decrease on up to ten dyes. More than 325 white-rot fungi (WRF) strains belonging to 76 fungal genera were compared with regards to their capability to decolourise five azo and two anthraquinone dyes as well as the dyes mixture. The most recalcitrant dyes belonged to the azo group. Several new species unstudied in the bioremediation field were found to be able to efficiently decolourise all the dyes tested.     

PERMANENT GENETIC RESOURCES: Isolation of microsatellite loci from the kelp, Saccorhiza polyschides (Heterokontophyta, incertae sedis)

Kelps are ecologically important seaweeds that dominate the subtidal zones of rocky coasts. In Northern Europe, Saccorhiza polyschides is a pioneer species suspected of outcompeting the harvested kelp, Laminaria digitata. To examine how the process of species competition affects species distribution and genetic diversity in coastal environments, we developed 10 polymorphic microsatellite markers for S. polyschides using an enriched library (microsatellites are already available for L. digitata). These loci showed from three to 24 alleles with heterozygosities ranging from 0.36 to 0.92. This polymorphism is high enough for fine-scale population analyses including assignment tests to determine the origin of recruits.     

CD11/CD18 cell surface adhesion glycoproteins: Discordance of monocyte function and expression in response to stimulation

The adherence of blood leukocytes to vascular endothelium precedes their diapedesis into the extravascular space. These processes require the expression of adherence glycoproteins on the cell surface of the leukocyte. The relative importance of these adherence molecules is so far poorly understood. However, there is evidence to suggest that a disparity exists between the surface receptor expression of these glycoproteins and leukocyte adherence to vascular endothelial cells in culture. We have investigated the importance of each of the adhesion glycoproteins CD11a, CD11b, and CD11c in mediating the adherence of human monocytes to endothelial cells in culture. We have also investigated the chronological relationship between changes in monocyte adherence to endothelial cells and the surface expression of CD11a, CD11b, and CD11c following stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP). The increase in adherence occurred within 1 minute, but declined if monocytes were preincubated with fMLP for up to 30 minutes. The surface expression of adherence molecules demonstrated a significant increase in CD11a and CD11b in the presence of fMLP after 10 min and was maintained while monocyte adherence to endothelium declined. These changes in surface receptor expression were quantitated using an immunolabeling technique. It is suggested that fMLP stimulation of monocyte adherence is unlikely to be solely dependent on increased surface receptor expression of adhesion molecules.     

Decrease of enteric micro-organisms from rural sewage sludge during their composting in straw mixture

AIMS: To study the decrease of enteric micro-organisms including viable nematode eggs, enteroviruses, faecal indicators (Escherichia coli and enterococci) and pathogenic bacteria (Listeria monocytogenes, Salmonella sp. and Clostridium perfringens) of a rural sewage sludge when it is composted for 7 months in mixture with straw. METHODS AND RESULTS: Numbers of the test organisms and the physico-chemical parameters were measured on a monthly basis on the mixture, on the compost after being turned, and on the pile in three positions representing the part by which air is incoming, the bottom of the pile and the part through which air is outgoing. The lowest temperature in the pile was observed at the bottom, where it did not exceed 50 degrees C against 66 degrees C in the two other areas. There were no significant differences between the three areas in terms of micro-organism survival. Infectious enteroviruses were inactivated rapidly and were not found after the first turning whereas some genomes were detected until after the third turning. Escherichia coli and enterococci presented a similar survival rate and their number decreased by 4 log(10) whereas Salmonella decayed at a greater rate than L. monocytogenes. The numbers of C. perfringens decreased gradually to reach a final concentration in the mature compost of about 10(2) CFU g(-1) dry matter (d.m.), which was similar to that of the faecal indicators. CONCLUSIONS: The hygienic effect of sludge composting in mixture with straw results in a significant reduction of enteric micro-organisms, the concentration of the faecal indicators in the final product being < 64 most probable number g(-1) d.m. The concentrations of Salmonella, enteroviruses and viable nematode eggs in the final product were not detectable which is in accordance with the French legislation. SIGNIFICANCE AND IMPACT OF THE STUDY: The results which pointed out the different behaviour of the test micro-organisms reflect the difficulty to propose a relevant indicator of hygienization. Otherwise, they show that composting is an efficient means for hygienization of sludge of rural wastewater treatment, where the straw is available close to their place of production.     

TRbase: a database relating tandem repeats to disease genes for the human genome

MOTIVATION: Tandem repeats are associated with disease genes, play an important role in evolution and are important in genomic organization and function. Although much research has been done on short perfect patterns of repeats, there has been less focus on imperfect repeats. Thus, there is an acute need for a tandem repeats database that provides reliable and up to date information on both perfect and imperfect tandem repeats in the human genome and relates these to disease genes. RESULTS: This paper presents a web-accessible relational tandem repeats database that relates tandem repeats to gene locations and disease genes of the human genome. In contrast to other available databases, this database identifies both perfect and imperfect repeats of 1-2000 bp unit lengths. The utility of this database has been illustrated by analysing these repeats for their distribution and frequencies across chromosomes and genomic locations and between protein-coding and non-coding regions. The applicability of this database to identify diseases associated with previously uncharacterized tandem repeats is demonstrated.     

The human adipose tissue is a source of multipotent stem cells

Multipotent stem cells constitute an unlimited source of differentiated cells that could be used in pharmacological studies and in medicine. Recently, several publications have reported that adipose tissue contains a population of cells able to differentiate into different cell types including adipocytes, osteoblasts, myoblasts, and chondroblasts. More recently, stem cells with a multi-lineage potential at the single cell level have been isolated from human adipose tissue. These cells, called human Multipotent Adipose-Derived Stem (hMADS) cells, have been established in culture and interestingly, maintain their characteristics with long-term passaging. The adipocyte differentiation of hMADS cells has been thoroughly studied and differentiated cells exhibit the unique feature of human adipocytes. Finally, potential applications of stem cells isolated from adipose tissue in medicine will be discussed.     

Degradation of wheat straw by Fibrobacter succinogenes S85: a liquid- and solid-state nuclear magnetic resonance study

Wheat straw degradation by Fibrobacter succinogenes was monitored by nuclear magnetic resonance (NMR) spectroscopy and chemolytic methods to investigate the activity of an entire fibrolytic system on an intact complex substrate. In situ solid-state NMR with 13C cross-polarization magic angle spinning was used to monitor the modification of the composition and structure of lignocellulosic fibers (of 13C-enriched wheat straw) during the growth of bacteria on this substrate. There was no preferential degradation either of amorphous regions of cellulose versus crystalline regions or of cellulose versus hemicelluloses in wheat straw. This suggests either a simultaneous degradation of the amorphous and crystalline parts of cellulose and of cellulose and hemicelluloses by the enzymes or degradation at the surface at a molecular scale that cannot be detected by NMR. Liquid-state two-dimensional NMR experiments and chemolytic methods were used to analyze in detail the various sugars released into the culture medium. An integration of NMR signals enabled the quantification of oligosaccharides produced from wheat straw at various times of culture and showed the sequential activities of some of the fibrolytic enzymes of F. succinogenes S85 on wheat straw. In particular, acetylxylan esterase appeared to be more active than arabinofuranosidase, which was more active than alpha-glucuronidase. Finally, cellodextrins did not accumulate to a great extent in the culture medium.     

Phosphatidylinositol increases HDL-C levels in humans

Studies have shown that phosphatidylinositol (PI) can stimulate reverse cholesterol transport by enhancing the flux of cholesterol into HDL and by promoting the transport of high density lipoprotein-cholesterol (HDL-C) to the liver and bile. The goal of this study was to determine the safety and therapeutic value of PI after oral administration to normolipidemic human subjects. We performed a randomized 2 week study in 16 normolipidemic subjects. Subjects received either 2.8 or 5.6 g of PI, with or without food. PI was well tolerated by all subjects. PI significantly affected the levels of HDL-C and triglyceride in the plasma of subjects receiving PI with food. The lower dose showed a 13% increase in HDL-C, whereas the high dose showed an increase of 18% over the 2 week period. Both low- and high-dose groups showed significant increases in plasma apolipoprotein A-I. The high dose of PI also decreased plasma triglycerides by 36% in the fed subjects. These data suggest that after only 2 weeks, PI may have a comparable therapeutic value to niacin, with negligible side effects.