Abstract：Addition with exogenous microbial inoculum has been proven to be an efficient method to promote lignocellulose biodegradation during cattle manure composting process. In this study, the effects of anctinobacterial community were investigated in compost with microbial inoculum compared with blank control compost under the same condition. The results showed that the inoculated compost was characterized by reaching the thermophilic phase on the third day and keeping high temperature phase for 20 d (blank control compost for 14 d). Moreover, the CMCase activities in the inoculated compost were higher than the blank control compost. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) was carried out and sequenced in order to assess the antinobacterial diversity in both inoculated compost and blank control compost. The phylogenetic tree was based on sequences of the actinomycic 16S rRNA gene sequencing fragments, which showed different actinobateria were dominant in different phases during composting process. A total of 10 dominant sequences were obtained during the different composting phases. The dominated band which identified by BLAST during the thermophiclic phase was arranged in 3 classes as follows: Nocardiopsis sp., Streptomyces sp. and Arthrobacter sp.. Most of the actinobacterial bands identified in inoculated sample were related to the reported cellulose-decomposing strains during thermophiclic phase. The results revealed that compost with exogenous microbial inoculum could raise the high temperature and prolong the thermophiclic phase. Moreover, it could promote the actinobacterial activities effectively, resulting in an abundant and diverse actinobacterial community. The present study provides the scientific basis and technical guidance for the research of actinobacterial functional diversity during the composting process.
