Production of ethanol and xylitol by Trametes membranacea

Bioprocess and Biosystems Engineering - The potential to produce ethanol and xylitol from xylose by the macro basidiomycete Trametes membranacea was evaluated. All strains studied showed ethanol...     

Characterization of an acyltransferase acting on p21N-ras protein in a cell-free system

We have identified a protein-acyltransferase activity in membranes from mouse fibroblasts which transfers palmitate from palmitoyl-CoA to p21N-ras. Specificity of acylation has been confirmed by linkage analysis using hydroxylamine and by peptide mapping of in vivo and in vitro acylated p21N-ras. The acylation was temperature- and time-dependent, and prevented by prior boiling of membranes, consistent with an enzymatic process. The activity was detected in membranes, but not cytosol, and co-fractionated on Percoll gradients with Golgi markers. Cytosolic p21N-ras from mouse fibroblasts, which is C-terminally modified at its CAAX sequence, was a better substrate for the enzyme that recombinant bacterially expressed, unmodified p21N-ras. The activity could be solubilised in non-ionic detergents, making it amenable to purification.     

Isolation and partial characterization of a non-motile mutant ofClostridium acetobutylicum

Summary A non-motile mutant ofClostridium acetobutylicum, morphologically indistinguishable from the motile parent, was capable of solvent production, suggesting that motility is not a regulatory trigger for solventogenesis. However, solventogenesis was considerably weaker than that of the parent, providing evidence of a positive relationship between solvent production and motility.     

Physical and chemical characters,phytoplankton and primary production of Ezequiel Ramos Mexía Reservoir (Argentina)

We describe the distribution in space and time of a series of physical and chemical variables, phyto-plankton, and primary production in Ezequiel Ramos Mexía Reservoir (Argentina). Its waters are soft, poor in nutrients and with a low transparency that greatly depresses primary production. Phytoplankton data indicate the presence of 79 taxa with Bacillariophyceae, Cyanophyta and Chlorophyta alternatively dominant. Chlorophyll a was always low and never exceeded 3 mg m⁻³. Based on these results, the trophic status of this ecosystem is discussed.     

Specific detection of human and rabbit glucagon mRNA using a synthetic oligodeoxynucleotide

A unique 14 base oligodeoxynucleotide dTTCATCAGCCACTG complementary to glucagon mRNA was deduced from the amino acid sequence of the hormone (residues 24–28; GLN-TRP-LEU-MET-ASN). The oligonucleotide specifically hybridized to RNA from rabbit pancreas and human pancreatic islet cells. No detectable hybridization was observed with either yeast or rat liver RNA. The melting temperature of the hybrids was 50 ± 5°C indicating no significant mismatch for human or rabbit glucagon mRNA. Hybridization kinetics followed a single pseudofirst-order reaction (Cot_{0 · 5} = 2.5 × 10^?4 M sec). From the extent of reaction at completion there are a minimum of 43 fmol glucagon mRNA/mg RNA (total pancreas).     

New World Simian Foamy Virus Infections In Vivo and In Vitro

Foamy viruses (FV) are complex retroviruses that naturally infect all nonhuman primates (NHP) studied to date. Zoonotic transmission of Old World NHP simian foamy viruses (SFV) has been documented, leading to nonpathogenic persistent infections. To date, there have been no reports concerning zoonotic transmission of New World monkey (NWM) SFV to humans and resulting infection. In this study, we developed a Western blot assay to detect antibodies to NWM SFV, a nested PCR assay to detect NWM SFV DNA, and a β-galactosidase-containing indicator cell line to assay replication of NWM SFV. Using these tools, we analyzed the plasma and blood of 116 primatologists, of whom 69 had reported exposures to NWM. While 8 of the primatologists tested were seropositive for SFV from a NWM, the spider monkey, none had detectable levels of viral DNA in their blood. We found that SFV isolated from three different species of NWM replicated in some, but not all, human cell lines. From our data, we conclude that while humans exposed to NWM SFV produce antibodies, there is no evidence for long-term viral persistence.     

Genes Similar to the Vibrio parahaemolyticus Virulence-Related Genes tdh,tlh, and vscC2 Occur in Other Vibrionaceae Species Isolated from a Pristine Estuary

Detection of the human pathogen Vibrio parahaemolyticus often relies on molecular biological analysis of species-specific virulence factor genes. These genes have been employed in determinations of V. parahaemolyticus population numbers and the prevalence of pathogenic V. parahaemolyticus strains. Strains of the Vibrionaceae species Photobacterium damselae, Vibrio diabolicus, Vibrio harveyi, and Vibrio natriegens, as well as strains similar to Vibrio tubiashii, were isolated from a pristine salt marsh estuary. These strains were examined for the V. parahaemolyticus hemolysin genes tdh, trh, and tlh and for the V. parahaemolyticus type III secretion system 2α gene vscC2 using established PCR primers and protocols. Virulence-related genes occurred at high frequencies in non-V. parahaemolyticus Vibrionaceae species. V. diabolicus was of particular interest, as several strains were recovered, and the large majority (>83%) contained virulence-related genes. It is clear that detection of these genes does not ensure correct identification of virulent V. parahaemolyticus. Further, the occurrence of V. parahaemolyticus-like virulence factors in other vibrios potentially complicates tracking of outbreaks of V. parahaemolyticus infections.