Abstracto

Effects of microgravity on the phenotype, genome and transcriptome of Streptococcus pneumoniae

Jia Li, Yinghua Guo, Guogang Xu, Xuelin Zhang, Lei Pan, Hong Zhong, Chou Xu, Changting Liu

Objective: Microgravity can influence pathogenic bacteria by modifying their various biological characteristics. However, how microgravity affects Streptococcus pneumoniae and the relevant mechanisms are unclear. Methods: A multidrug-resistant Streptococcus pneumoniae strain was cultured in a microgravity or gravity environment for 16 h. Subsequently, various phenotypic assays, including morphology, growth curves, biofilm formation, and acid and base stress, were performed. Combined genomic and transcriptomic analysis was performed. Results: Compared with the gravity and parental strain, the morphology, growth curve, and biofilm formation of the microgravity strain were unchanged, while the microgravity strain increased resistance to weak acid and base solutions and lost the ability to utilize glucuronamide. Comparative genomic and transcriptomic analyses revealed that the microgravity strain had gene expression changes related to metabolism, cell wall/capsule, and cellular defense mechanisms. Conclusion: Our study reveals that microgravity has a significant influence on the metabolism and adaptation of Streptococcus pneumoniae, which shows great flexibility and adaptability to successfully survive by regulating multiple physiological functions and cellular pathways. It may provide new insights into space microbiology.