Detoxifying enzyme activity in worker honey bees: an adaptation for foraging in contaminated ecosystems

The activities of two important groups of detoxifying enzymes, the glutathione S-transferases and the mixed-function oxidases, were assayed throughout the lifetimes of worker honey bees (Apis mellifera L.). Detoxification capacity decreased on a per insect basis in older workers and was associated with a dramatic loss of midgut protein. However, analysis of specific activity (enzyme activity per milligram protein) showed increasing activity levels as bees aged and began to forage. These results show that foraging worker honey bees compensate for protein loss by increasing the activity of important enzymes, suggesting a possible biochemical adaptation for foraging in contaminated ecosystems.