The Influence of Bt-Transgenic Maize Pollen on the Bacterial Diversity in the Midgut of Chinese Honeybees, Apis cerana cerana

Using culture-independent technique polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and conventional culture techniques, ecological risk of transgenic maize pollen on gut bacteria of the Chinese honeybee, Apis cerana cerana, was assessed. Honeybees were fed with Bt-transgenic maize pollen, non-transgenic near isoline pollen, linear cry1Ah gene (800 ng mL−1) and supercoiled plasmid DNA (800 ng mL−1) under laboratory conditions. The DGGE profile showed that the number of DGGE bands varied from 10.7 to 14.7 per sample, and the Shannon's index ranged from 0.85 to 1.00. The similarity calculated by PAST was mostly above 92%, indicating no obvious changes among treatments or within replicates. 14 bacterial strains affiliated with Alphaproteobacteria, Gammaproteobacteria, Firmicutes, and Actinobacteria were isolated and characterized on media under aerobic and anaerobic conditions. These results demonstrated that transgenic cry1Ah maize pollen did not induce significant changes of the honeybee gut bacterial community composition under laboratory conditions.