Evidence of defined temporal expression patterns that lead a gram-negative cell out of dormancy

Abstract

Many bacterial species are capable of forming long-lived dormant cells. The best characterized are heat and desiccation resistant spores produced by many Gram-positive species. Less characterized are dormant cysts produced by several Gram-negative species that are somewhat tolerant to increased temperature and very resistant to desiccation. While there is progress in understanding regulatory circuits that control spore germination, there is scarce information on how Gram-negative organisms emerges from dormancy. In this study, we show that R. centenum cysts germinate by emerging a pair of motile vegetative cells from a thick cyst cell wall coat~6 hrs post induction of germination. Time-lapse transcriptomic analysis reveals that there is a defined temporal pattern of gene expression changes during R. centenum cyst germination. The first observable changes are increases in expression of genes for protein synthesis, an increase in expression of genes involved in the generation of a membrane potential and the use of this potential for ATP synthesis via ATPase expression. These early events are followed by expression changes that affect the cell wall and membrane composition, followed by expression changes that promote chromosome replication. Midway through germination, expression changes occur that promote the flow of carbon through the TCA cycle to generate reducing power and parallel synthesis of electron transfer components involved in oxidative phosphorylation. Finally, late expression changes promote the synthesis of a photosystem as well as flagellar and chemotaxis components for motility.

Combatting Persister Cells With Substituted Indoles

“…Furthermore, ppGpp plays a role in hpf expression in P. aeruginosa ( Akiyama et al, 2018 ). Critically, for cysts of Rhodospirillum centenum , the first genes activated for waking encode for ribosomes and translation machinery (initiation, elongation, and release factors) ( Ashok and Bauer, 2020 ); hence, it appears the PRDP model holds for many species and resting states.…”

No Light, No Germination: Excitation of the Rhodospirillum centenum Photosynthetic Apparatus Is Necessary and Sufficient for Cyst Germination

“…The plates were then incubated in the dark at 37°C for 48 to 60 h to allow the development of cyst-containing rugose colonies. For spectral analysis of cysts, the cysts were separated from vegetative cells (purified) using lysozyme disruption as described previously ( 17 ).…”

“…Recently, we have also initiated analysis of the germination phase of the R. centenum cyst developmental life cycle ( 17 ). This study defined different stages of germination based on microscopic and genome-wide transcription changes.…”

Eradicating Bacterial Persister Cells with Substituted Indoles to Reduce Antibiotic Resistance

“…또한 ppGpp는 P. aeruginosa에서 hpf 발현을 유도한다 [53]. Rhodospirillum centenum 낭포의 경우 세포가 활성화되기 위해 첫 번째로 암호화된 유전자들은 리보솜과 번역 시스템(개시, 신장, 종결)과 관련되어 있다 [55]. 따라서 PRDP 모델은 많은 종의 휴면 상태를 규명 가능하다.…”