The composition and function of bacterial communities in Bombyx mori (Lepidoptera: Bombycidae) changed dramatically with infected fungi: A new potential to culture Cordyceps cicadae

• Published in: Insect molecular biology 2024-12, Vol.33 (6), p.613-625
• Main Authors: Zhou, Ye‐Ming, Duan, Lin, Luo, Li, Guan, Jing‐Qiang, Yang, Zheng‐Kai, Qu, Jiao‐Jiao, Zou, Xiao
• Format: Article
• Language: English
• Subjects: Abundance; Animals; artificial cultivation; Bacteria; Bacteria - classification; Bacteria - genetics; bacterial community; Beauveria - genetics; Beauveria - pathogenicity; Beauveria - physiology; Bombycidae; Bombyx - growth & development; Bombyx - microbiology; Bombyx mori; Community composition; Community structure; Composition; Cordyceps; Cordyceps - genetics; Cordyceps cicadae; Cordycipitaceae; Entomopathogenic fungi; Fungal infections; Fungi; Herbal medicine; Hypocreales; Larva - growth & development; Larva - microbiology; Larvae; Lepidoptera; Metabolites; Microbiota; Pathogenicity; Pathogens; phylogenetic relationship; Phylogenetics; Phylogeny; Sequences; Silkworms; Similarity
• ISSN: 0962-1075; 1365-2583; 1365-2583
• DOI: 10.1111/imb.12918

Cordyceps cicadae (Hypocreales: Cordycipitaceae) is a renowned entomopathogenic fungus used as herbal medicine in China. However, wild C. cicadae resources have been threatened by heavy harvesting. We hypothesised that Bombyx mori L. (Lepidoptera: Bombycidae) could be a new alternative to cultivate C. cicadae due to the low cost of rearing. Bacterial communities are crucial for the formation of Cordyceps and for promoting the production of metabolites. To better understand the bacterial community structure associated with Cordyceps, three Claviciptaceae fungi were used to explore the pathogenicity of the silkworms. Here, fifth‐instar silkworms were infected with C. cicadae, Cordyceps cateniannulata (Hypocreales: Cordycipitaceae) and Beauveria bassiana (Hypocreales: Cordycipitaceae). Subsequently, we applied high‐throughput sequencing to explore the composition of bacterial communities in silkworms. Our results showed that all three fungi were highly pathogenic to silkworms, which suggests that silkworms have the potential to cultivate Cordyceps. After fungal infection, the diversity of bacterial communities in silkworms decreased significantly, and the abundance of Staphylococcus increased in mummified larvae, which may play a role in the death process when the host suffers infection by entomopathogenic fungi. Furthermore, there were high similarities in the bacterial community composition and function in the C. cicadae and C. cateniannulata infected samples, and the phylogenetic analysis suggested that these similarities may be related to the fungal phylogenetic relationship. Our findings reveal that infection with different entomopathogenic fungi affects the composition and function of bacterial communities in silkworms and that the bacterial species associated with Cordyceps are primarily host dependent, while fungal infection affects bacterial abundance. In this study, we showed that Bombyx mori larvae had the potential to cultivate Cordyceps, because Cordyceps fungi were highly pathogenic on the silkworms and the low cost of rearing silkworms. After fungal infection, the diversity of bacterial communities in silkworms decreased significantly, and the abundance of Staphylococcus increased in mummified larvae, which may participate in the death process when host suffered the infection of entomopathogenic fungi. The infection of different entomopathogenic fungi affects the composition and function of bacterial communities in the silkworm, and the bacteri