Biochemical and taxonomic characterization of bacteria associated with the crucifer root maggot (Delia radicum)

The crucifer root maggot, Delia radicum, is an important pest of cruciferous crops; however, little is known about its digestive biochemistry or resident gut microbiota. A culturing approach was used to survey the types of micro organisms associated with eggs, midgut, and faeces of larvae feeding on rutabaga. All bacteria isolated from the midgut and faecal materials were Gram-negative bacilli. Nine types of culturable bacteria were identified within the midgut based on analysis of 60 kDa chaperonin sequences and were generally gamma-Proteobacteria, primarily Enterobacteriaceae. Carbohydrate utilization patterns, select biochemical pathways, and hydrolytic enzymes were examined using the API(R) system for each of the nine groups, revealing an exceptionally broad metabolic and hydrolytic potential. These studies suggest that resident alimentary tract microorganisms have the potential to contribute to host nutrition directly as a food source as well as by providing increased digestive potential.