The inoculation of biocontrol fungi may affect the community structure of microorganisms in the soil, and changes in soil microbial community structure may in turn affect the control effectiveness. This study focused on the most harmful invasive pest, the red imported fire ant Solenopsis invicta Buren. The highly pathogenic Beauveria bassiana strain HHY-B was applied to its nest to reveal the impact of pathogen infection on the nest microbial community structure of the red imported fire ant. The microbiome analysis was conducted on soil samples of B. bassiana infected ant nests after 48 and 96 hours, as well as uninfected ant nests using high-throughput sequencing technology. A total of 648 708 valid bacterial sequences were obtained, belonging to 38 phylum, 127 classes, 274 orders, 451 families and 897 genus. 898 443 fungal sequences were also obtained, belonging to 12 phylum, 38 classes, 88 orders, 197 families, 377 genus. The Proteobacteria and Actinobacteria dominated the soil bacterial community in ant nests. Treatment with B. bassiana significantly increased the relative abundance of Proteobacteria in ant nests (P<0.05), but had no significant effect on the relative abundance of Actinobacteria. Ascomycota dominated the fungal community in the nest soil, and its relative abundance treated with B. bassiana was significantly increased in ant nests (P<0.05). In terms of relative abundance at the genus level, the genus of Beauveria showed an dominate fungi in the two treatment groups, which was not found in the control group. The KEGG pathway analysis showed that the differential bacteria were mainly focused on metabolic pathways, biosynthesis of secondary metabolites, microbial metabolism in various environments, biosynthesis of amino acids, carbon metabolism, two-component systems, ribosomes and other metabolic pathways. The enrichment level of the pathways in the control group was higher than that in the treatment group. This study revealed the changes in the microbial community structure of the red imported fire ant nests after treatment with B. bassiana, which helps to the further understanding of the mechanism of B. bassiana on the red imported fire ants and the living environment, and provides theoretical basis for the biological control for the red imported fire ants.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |