Effect of Caffeine on Horizontal Gene Transfer
Abstract
Microbiomes have drawn a large interest in the scientific community in recent years (Hornung et al, 2019). Currently, it is postulated that Horizontal Gene Transfer (HGT), a common phenomenon that occurs across many bacterial species, happens in human gut microbiome as well (Liu et al, 2012). The flow of genetic information is fluid amongst this domain and can be exchanged between organisms through mechanisms such as transformation. Many studies have attributed that bacteria have co-evolved with their’ environment to survive. Wang et al. 2020 proposed that an exterior stressor evoked bacteria’s sense of survival which enhanced the DNA to uptake the recombination that ultimately promotes transformation (Wang et al 2020. In this case, shifting away from a normal growth environment has been suspected to induce stress to many different bacteria in many ways. With anti-bacterial effects, caffeine can successfully act as an exterior stressor to stimulate the transformation process. Through experiment, with exposure to caffeine in Escherichia coli culture, caffeine showed an enhancement effect on bacterial transformation. With preliminary RNA sequencing results, it was found that fumC, genetic sequence that encodes fumarase enzyme, were upregulated drastically when the sample is exposed to caffeine, along with its counterpart, fumA and fumB being deactivated or downregulated. This showed the presence of increase in ROS level in the cell culture when exposed to caffeine. With reference to a study of similar interest, increase in ROS level and exterior stress level, the cell permeability was increased, enhancing horizontal gene transfer. Therefore, it was hypothesized that with the presence of caffeine, the antimicrobial effect served as an exterior stressor to the bacteria, and that the bacteria's responses to stress would increase DNA uptake and recombination, promoting the bacterial transformation.
Citation
Liang, Qiushi (2022). Effect of Caffeine on Horizontal Gene Transfer. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /198139.