Open AccessBacterial community structures in honeybee intestines and their response to two insecticidal proteins
Author(s) -
Babendreier Dirk,
Joller David,
Romeis Jörg,
Bigler Franz,
Widmer Franco
Publication year - 2007
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2006.00249.x
Subject(s) - biology , terminal restriction fragment length polymorphism , bacillus thuringiensis , pollen , firmicutes , 16s ribosomal rna , gammaproteobacteria , trichoplusia , restriction fragment length polymorphism , bacillales , toxin , microbiology and biotechnology , botany , bacteria , larva , gene , genotype , noctuidae , genetics , bacillus subtilis
In this study, the effects of the Bt‐toxin Cry1Ab and a soybean trypsin inhibitor (SBTI) on intestinal bacterial communities of adult honeybees ( Apis mellifera ) were investigated. It was hypothesized that changes in intestinal bacterial communities of honeybees may represent a sensitive indicator for altered intestinal physiology. Honeybees were fed in a laboratory set‐up with maize pollen from the Bt‐transgenic cultivar MON810 or from the non‐transgenic near isoline. Purified Cry1Ab (0.0014% w/v) and SBTI (0.1% or 1% w/v) represented supplementary treatments. For comparison, free‐flying honeybees from two locations in Switzerland were analysed. PCR‐amplification of bacterial 16S rRNA gene fragments and terminal restriction fragment length polymorphism analyses revealed a total of 17 distinct terminal restriction fragments (T‐RFs), which were highly consistent between laboratory‐reared and free‐flying honeybees. The T‐RFs were affiliated to Alpha‐ , Beta‐ , and Gammaproteobacteria , to Firmicutes , and to Bacteriodetes . Neither Bt‐maize pollen nor high concentrations of Cry1Ab significantly affected bacterial communities in honeybee intestines. Only the high concentration of SBTI significantly reduced the number of T‐RFs detected in honeybee midguts, a concentration that also increases bee mortality. Therefore, total bacterial community structures may not be a sensitive indicator for providing evidence for the impact of insecticidal proteins on honeybees at sublethal levels.