Cultivable gut bacteria of scarabs (Coleoptera: Scarabaeidae) inhibit Bacillus thuringiensis multiplication.
The entomopathogen Bacillus thuringiensis is used to control various pest species of scarab beetle but is not particularly effective. Gut bacteria have diverse ecological and evolutionary effects on their hosts, but whether gut bacteria can protect scarabs from B. thuringiensis infection remains poorly understood. To investigate this, we isolated 32 cultivable gut bacteria from Holotrichia oblita Faldermann, Holotrichia parallela Motschulsky, and Anomala corpulenta Motschulsky, and analyzed their effect on B. thuringiensis multiplication and Cry toxin stability. 16S rDNA analysis indicated that these gut bacteria belong to the Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes phyla. A confrontation culture analyses of the 32 isolates against three scarab-specific B. thuringiensis strains showed that the majority of the scarab gut bacteria had antibacterial activity against the B. thuringiensis strains. The Cry toxin stability analysis results showed that while several strains produced proteases capable of processing the scarab-specific toxin Cry8Ea, none were able to completely degrade it. These results suggest that gut bacteria can potentially affect the susceptibility of scarabs to B. thuringiensis and that this should be considered when considering future control measures.
School of Life Science, Northeast Agricultural University, Harbin 150030, P. R. China.
Yueming
Y
Shan
Changlong
C
Shu
Neil
N
Crickmore
Chunqin
C
Liu
Wensheng
W
Xiang
Fuping
F
Song
Jie
J
Zhang
D000818:Animals; D000898:Antibiosis / Q000502:physiology*; D001413:Bacillus thuringiensis / Q000254:growth & development* / Q000378:metabolism; D000083722:Bacillus thuringiensis Toxins; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification*; D018407:Bacterial Physiological Phenomena; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D061046:Biological Control Agents; D001517:Coleoptera / Q000254:growth & development / Q000382:microbiology*; D004731:Endotoxins / Q000235:genetics / Q000378:metabolism; D041981:Gastrointestinal Tract / Q000382:microbiology; D005798:Genes, Bacterial; D006460:Hemolysin Proteins / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000382:microbiology; D064307:Microbiota; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013045:Species Specificity
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D061046:Biological Control Agents; D004731:Endotoxins; D006460:Hemolysin Proteins; D012336:RNA, Ribosomal, 16S; C030956:insecticidal crystal protein, Bacillus Thuringiensis