Impact of the microsporidian Nosema ceranae on the gut epithelium renewal of the honeybee, Apis mellifera.

The invasive microsporidian species, Nosema ceranae, causes nosemosis in honeybees and is suspected to be involved in Western honeybee (Apis mellifera) declines worldwide. The midgut of honeybees is the site of infection; the microsporidium can disturb the functioning of this organ and, thus, the bee physiology. Host defense against pathogens is not limited to resistance (i.

Optimisation of culture parameters for exopolysaccharides production by the microalga Rhodella violacea.

A unicellular Rhodophyte was identified by sequencing of its 18S rRNA encoding gene as belonging to the Rhodella violacea specie. With the objective to optimise the production of biomass and exopolysaccharide by this strain, effects of irradiance, pH and temperature on its photosynthetic activity were investigated. In a second time a stoichiometric study of the well-known f/2 medium led to its supplementation in N and P to increase biomass and then exopolysaccharide yields when the strain was cultivated in photobioreactors.