Glutathione S-transferase in the insect Apis mellifera macedonica kinetic characteristics and effect of stress on the expression of GST isoenzymes in the adult worker bee

The glutathione S-transferase present in the adult worker bee Apis mellifera macedonica was purified and analyzed for its physicochemical and kinetic properties. The enzyme is heterodimeric with subunit molecular masses of 29 and 25 kDa, respectively. Two main isoenzymes with distinct kinetic properties are present, with isoelectric points of 7.40 for the alkaline and 4.58 for the acidic forms, respectively. The two enzymes are induced independently by factors such as insecticide treatments and environmental conditions, including low temperatures or starvation.     

Glutathione S-transferase in the developmental stages of the insect Apis mellifera macedonica

We investigated the pattern of glutathione S-transferase (GST) activity in the course of the development of Apis mellifera macedonica. GST activity is present in all developmental stages of A. mellifera macedonica. The highest activity towards the substrate 1-chloro-2,4-dinitrobenzene (CDNB) is found in the adult stage and the lowest in the egg. The kinetic characteristics of the whole enzyme change as the insect develops. Significant changes are observed in substrate specificity, inhibitor sensitivity and V(max). The number of isoenzymes and their rate of expression vary as the insect develops. However, two main isoenzymes are present in all developmental stages, one in the alkaline area and the other in the acidic. While in the larval stage the acidic isoenzyme is expressed at a slightly higher rate (52.2% over 47.8% for the alkaline isoenzyme), in the adult stage, the rate is reversed dramatically (13.24% and 84.2%, respectively).     

Melissopalynological analysis of royal jelly from Greece

Microscopic analysis of 82 royal jelly samples obtained from several locations in Greece was carried out in order to study the pollen spectrum of Greek royal jelly. The analysis recorded over 60 taxa. The abundance of each pollen type varied among the areas and the samples. The most frequent pollen types found in the samples were Brassicaceae, Olea europaea, Eucalyptus, Trifolium, Rubus, Carduus-type, Hypericum, Daucus-type and Cistus. The majority of the pollen types found in the royal jelly samples were also found at the pollen flora around the apiaries.     

Development of a Cotton Honey-Based Spread by Controlling Compositional and Processing Parameters

Food Biophysics - Honey from cotton blossoms tends to crystallize rapidly resulting in a product with hard texture and low spreadability, even if it is processed via a controlled crystallization...