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The exploration of space is becoming more feasible, and with this comes the possibility of performing fermentations in microgravity. Our study explores the potential effects of microgravity on a standard brewing model fermentation. As the fermentation of barley wort has been studied for centuries, there is an established foundation of knowledge with which to compare any changes that occur under microgravity. A modified ASBC miniature fermentation protocol (Yeast-14) was conducted within a Yuri 2.0 microgravity chamber to examine the response of Saccharomyces pastorianus to simulated microgravity conditions. Our findings reveal that yeast exhibited accelerated growth rates under microgravity compared to standard conditions. Additionally, the microgravity environment led to significantly lower levels of volatile compounds such as isoamyl acetate and 2-phenethyl acetate in the final product. Further genetic analysis showed significant downregulation of the ATF2 gene in the control group, potentially the mechanism behind the observed decrease in volatile compounds. These results show that while fermentation under microgravity is likely to eventually be commonplace, there may be changes in rate and gene expression that are beneficial or detrimental to the final product depending upon the desired characteristics. [ABSTRACT FROM AUTHOR]

The opportunistic pathogen Pseudomonas aeruginosa (P. aeruginosa) is associated gastrointestinal (GI) inflammation and illness; however, factors motivating commensal-to-pathogen transition are unclear. Excessive zinc intake from supplements is common in humans. Due to the fact that zinc exposure enhances P. aeruginosa colonization in vitro, we hypothesized zinc exposure broadly activates virulence mechanisms, leading to inflammation and illness. P. aeruginosa was treated with excess zinc and growth, expression and secretion of key virulence factors, and biofilm production were determined. Effects on invasion, barrier function, and cytotoxicity were evaluated in Caco-2 cells co-cultured with P. aeruginosa pre-treated with zinc. Effects on colonization, mucosal pathology, inflammation, and illness were evaluated in mice infected with P. aeruginosa pre-treated with zinc. We found the expression and secretion of key virulence factors involved in quorum sensing (QS), motility (type IV pili, flagella), biosurfactants (rhamnolipids), toxins (exotoxin A), zinc homeostasis (CzcR), and biofilm production, were all significantly increased. Zinc exposure significantly increased P. aeruginosa invasion, permeability and cytotoxicity in Caco-2 cells, and enhanced colonization, inflammation, mucosal damage, and illness in mice. Excess zinc exposure has broad effects on key virulence mechanisms promoting commensal-to-pathogen transition of P. aeruginosa and illness in mice, suggesting excess zinc intake may have adverse effects on GI health in humans. [ABSTRACT FROM AUTHOR]