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

Abstract

Endophytic bacteria in Sphagnum palustre have a growth-promoting effect on plants. In this study, the endophytic bacterium strain J11 in S. palustre was isolated and identified as Bacillus cereus, and its growth cycle, functional characteristics, and effects on maize growth were analyzed. The results indicate that as B. cereus, 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 B. cereus from S. palustre. 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.