Transcriptional Profiling of the Probiotic Escherichia coli Nissle 1917 Strain under Simulated Microgravity

Abstract

Long-term space missions affect the gut microbiome of astronauts, especially the viability of some pathogens. Probiotics may be an effective solution for the management of gut microbiomes, but there is a lack of studies regarding the physiology of probiotics in microgravity. Here, we investigated the effects of microgravity on the probiotic Escherichia coli Nissle 1917 (EcN) by comparing transcriptomic data during exponential and stationary growth phases under simulated microgravity and normal gravity. Microgravity conditions affected several physiological features of EcN, including its growth profile, biofilm formation, stress responses, metal ion transport/utilization, and response to carbon starvation. We found that some changes, such as decreased adhesion ability and acid resistance, may be disadvantageous to EcN relative to gut pathogens under microgravity, indicating the need to develop probiotics optimized for space flight.

Effects of Simulated Microgravity on the Physiology of Stenotrophomonas maltophilia and Multiomic Analysis

“…the NG group (Yim et al, 2020). The biofilm formation of the bacterial pathogen S. typhimurium was also increased after the space shuttle mission STS-115 (Wilson et al, 2007).…”

“…Considering the different culture conditions, cultivation times, and strains used, previous study showed that microorganisms exposed to a space environment or cultivated in the SMG environment on the ground exhibited different growth characteristics. Most researchers have shown that microgravity or weightlessness in space can significantly increase the growth rate of bacteria (Benoit and Klaus, 2007;Kim et al, 2013;Javadi et al, 2014;Yim et al, 2020). Compared with ground group, some studies have shown that under microgravity or weightlessness conditions, the growth rate of some bacteria does not change significantly (Coil et al, 2016;Fajardo-Cavazos et al, 2018).…”

Combined Impact of Magnetic Force and Spaceflight Conditions on Escherichia coli Physiology

“…The most prominent feature of the spaceflight (SF) conditions is microgravity associated with low shear fluid dynamics and the absence of convection currents [1,2,21]. Many studies demonstrated that bacteria show a species-and strain-specific response to microgravity, including changes in morphology, physiology, metabolism, and virulence [4][5][6][7]10,[22][23][24].…”

Insulated expression of periplasmic uricase inE. coliNissle 1917 for the treatment of hyperuricemia

“…Previous studies have attempted to insert exogenous genes near the malEK, malPT , and yicS/nepI genes in EcN 32,63 ; however, these types of genomic editing may interfere with native gene transcription 32,38 . As the design of ultra-stable genetic editing in E. coli is important for living therapeutics 38 , we characterized an “insulated site” in the EcN genome by analyzing previous transcriptome data of EcN under different conditions 32,40,41 . This “insulated site” is flanked by two naturally appositive terminators.…”

“…To minimize the influence of uricase expression on global gene expression as well as probiotic properties of EcN, we selected a site located between uspG and ahpF (Supplementary Fig. 2a) for exogenous gene integration in the EcN genome, as this non-coding region showed markedly low gene transcription comparing with the surrounding coding regions based on published RNA-sequencing data [40][41][42] . The 3'-end of both uspG and ahpF showed two opposite ρ-independent terminator structures, T1 and T2, respectively (Supplementary Fig.…”