Construction and functional screening of a metagenomic library using a T7 RNA polymerase-based expression cosmid vector.

The metagenomic approach has greatly accelerated the discovery of new enzymes by giving access to the genetic potential of microorganisms from various environments. Function-based screening depends on adequate expression of the foreign genes in the heterologous host, which can be challenging in large-insert libraries. In this study, the shuttle cosmid vector pFX583 was used for the construction and screening of a metagenomic library.

Expression and characterization of a novel heterologous moderately thermostable lipase derived from metagenomics in Streptomyces lividans.

Seven lipolytic genes were isolated and sequenced from a metagenomic library that was constructed following biomass enrichment in a fed-batch bioreactor submitted to high temperature (50-70 degrees C) and alkaline pH (7-8.5). Among those sequences, lipIAF1-6 was chosen for further study and cloned in Streptomyces lividans 10-164.

Selective spread of neurotropic herpesviruses in the rat hippocampus.

Transsynaptically spreading viruses are widely used for tracing neuronal circuits in both the central and peripheral nervous systems. However, viruses are capricious tools with selective spreading properties that can produce false-negative results. Using herpes simplex virus type 1 and two pseudorabies virus strains, we aimed at mapping quantitatively neuronal connections in the rat hippocampus.

Cell type-specific action of seizure-induced intracellular zinc accumulation in the rat hippocampus.

Increased levels of intracellular zinc have been implicated in neuronal cell death in ischaemia, epilepsy and traumatic brain damage. However, decreases in zinc levels also lead to increased neuronal death and lowered seizure threshold. In the present study we investigated the physiological role of zinc in neurodegeneration and protection following epileptic seizures.