Abstract:The aim of the present study is to explore the dynamics of the diversity of actinomycetes and physical and chemical properties of soil during the process of swallowing of earthworms. Surrounding living soil of earthworms, intestinal contents, and earthworm feces acted as the special habitat soils of prophase, metaphase, and anaphase during the process. The pure culture method was used to separate and purify actinomycetes from the three phases, and a clone library was constructed to analyze the diversity of actinomycetes. The soil physical-chemical properties in three phases were determined according to the national standard. The correlation of physical-chemical properties of soil and the diversity of actinomycete was analyzed by using the principal component analysis and the correlation analysis. Results showed that 27, 15, and 17 actinomycetes were separated from living soil, intestinal contents, and earthworm feces, respectively. Morphological analysis and 16S rDNA sequencing showed that actinomycetes from living soil belonged to Actinosynnema, Streptomyces, and Nocardiopsis, whereas those separated from the intestinal contents and feces belonged to Streptomyces. The diversity of actinomycetes declined in relation to living soil, feces, and intestinal contents. Clone libraries of living soil, intestinal contents, and feces had 40, 20, and 30 operational taxonomic units (OTUs) divided into 11, 6, and 6 families; 24%, 3.3%, and 11.7% were unknown bacterium. The dominant actinomycetes were Nocardioidaceae, Microbacteriaceae, and Streptomycetaceae, respectively. There was no significant difference of total P content between the three phases. The physical and chemical properties of living soil were the lowest. The intestinal contents had the most contents of available N, whereas feces had the most contents of organic matter, total N and K, and available P. The principal component analysis and the correlation analysis showed that available P, total N, total P, available P, and organic matter content of the soil had a great influence on the diversity of actinomycetes. There was a negative relationship between the content of available P, total N, and actinomycete diversity in the process of swallowing of earthworms, whereas the coefficient was -0.998 and -1, respectively. The present study provided a theoretical basis for further research on the relationship among earthworms, soil, and actinomycetes.