Transition of microbial diversity in soil during PBSA film degradation. PCR-DGGE profile of 18S rDNA of soil treated with water (control), culture filtrate, PBSA film and water, and PBSA film and culture filtrate. M: marker, S: untreated soil. Number 1 to 4 means treatment week. Closely related species based on the similarity in the sequence of the same band are as follows: a, Asperigillus sp., b, Penicillium sp., c. Paecilomyces sp., d., Penicillium decumben, f. strain B47-9, g, Isaria takamizusanensis or Paecilomyces lilacinu, h., Paecilomyces sp. , e.i. and j, Acanthamoeba sp.