Transcriptomic Analysis Reveals that Changes in Gene Expression Contribute to Microbacterium sediminis YLB-01 Adaptation at Low Temperature Under High Hydrostatic Pressure

Microbes living in extreme environments often adopt strategies for survival, however, only a few studies have examined the adaptive mechanism of deep-sea bacteria in in-situ environments. In this study, transcriptomic data of the deep-sea piezotolerant and psychrotolerant actinomycete Microbacterium sediminis YLB-01 under the conditions of NPNT (normal temperature and pressure: 28 degrees C, 0.1 MPa), HPNT (normal temperature and high pressure: 28 degrees C, 30 MPa), NPLT (low temperature and atmospheric pressure: 4 degrees C, 0.1 MPa) and HPLT (low temperature and high pressure: 4 degrees C, 30 MPa) were examined and compared. Transcriptome results showed that M. sediminis YLB-01 responds to deep-sea low temperature under high-pressure environments by upregulating the ABC transport system, DNA damage repair response, pentose phosphate pathway, amino acid metabolism and fatty acid metabolism, while down-regulating division, oxidative phosphorylation, the TCA cycle, pyruvate metabolism, ion transport and peptidoglycan biosynthesis. Seven key genes specifically expressed under HPLT conditions were screened, and these genes are present in many strains that are tolerant to low temperatures and high pressures. This study provides transcription level insights into the tolerance mechanisms of M. sediminis YLB-01 in a simulated deep-sea in situ environment.

Automated summary

This study examined the transcriptomic data of deep-sea bacteria Microbacterium sediminis YLB-01 under different temperature and pressure conditions, revealing its adaptive mechanism in high-pressure and low-temperature environments. The bacterium responds to the environment by upregulating genes related to transport system, DNA repair, metabolic pathways, and down-regulating genes involved in division, energy production, and cell wall synthesis. Seven key genes specifically expressed under low temperature and high pressure conditions were identified. This study provides insights into the transcription-level tolerance mechanisms of M. sediminis YLB-01 in a simulated deep-sea in situ environment.