Identification and Functional Analysis of Endophytic Bacteria Bacillus cereus in Sphagnum palustre

Endophytic bacteria in <i>Sphagnum palustre</i> have a growth-promoting effect on plants. In this study, the endophytic bacterium strain J11 in <i>S. palustre</i> was isolated and identified as <i>Bacillus cereus</i>, and its growth cycle, functional characteristics, and effects on maize growth were analyzed. The results indicate that as <i>B. cereus,</i> the growth cycle of J11 consists of four phases, and the logarithmic phase lasts 2~24 h, with the abilities of phosphorus solubilization, protease, IAA, siderophore, and NH₃ production. The phosphorus solubilization ability of J11 ranges from 1.66 ± 0.07 to 1.98 ± 0.07 mg/L, and the IAA production varies from 1.51 ± 0.07 to 8.67 ± 0.16 mg/L. It has a growth-promoting effect on maize by increasing the seed germination rate by 29.27%, plant height by 4.21%, leaf length by 17.12%, leaf width by 29.51%, above-ground fresh weight by 50.79%, below-ground fresh weight by 46.30%, and chlorophyll content by 56.81%. This study represents the first report on the isolation and identification of <i>B. cereus</i> from <i>S. palustre</i>. Furthermore, this study systematically investigated its multiple plant growth-promoting traits and functional characteristics. These findings provide valuable resources and a theoretical foundation for the development and functional exploration of microbial resources in agricultural applications.