Introduction
It is essential to note that Escherichia coli, or E. coli, is among the most well-known prokaryotic microorganisms. It has a complex and multifaceted role, being both helpful and harmful to humans. On the one hand, E. coli can be the cause of severe foodborne diseases, including food poisoning. On the other hand, bacteria are beneficial to humans in both scientific and technological applications. The given analysis will be a summative review of a study conducted on E. Coli titled “Phenotypic Changes Exhibited by E. Coli Cultured in Space.” The article is fascinating, engaging, and insightful in its understanding of the intracellular changes that occur under conditions of space cultivation.
Description of Background
Space travel and exploration have always been of prime interest to science and technology as an essential centerpiece of the human future. For example, the National Aeronautics and Space Administration (NASA) is actively working on the Mars colonization project (General Services Administration & the Office of Management and Budget, 2021). It is stated that NASA “is the United States government agency responsible for U.S. space exploration, space technology, Earth and space science, and aeronautics research … new frontiers, discovering new knowledge, and developing new technology” (General Services Administration & the Office of Management and Budget, 2021, para. 2).
Therefore, comprehending the effects and consequences of exposure to weightlessness, as well as understanding the conditions of space, is essential to determine how cells adapt to such an environment. E. Coli is an excellent model organism to study these cellular transformations, which is why Zea et al. (2017) conducted research on phenotypic changes in the bacteria sent to space. The primary purpose was to understand the underlying cellular changes arising from the exposure of E. coli colonies to space conditions during spaceflight missions.
Hypothesis
The key hypothesis under investigation was that E. coli would undergo cellular adaptation changes under weightless conditions. The primary areas of interest included “assessments of final cell count, cell envelope thickness, cell size, cell ultrastructure, and culture morphology” (Zea et al., 2017, p. 1). In other words, the researchers expected that the weightlessness of space and other conditions would alter how the bacteria grow and develop.
Results and Techniques
In the case of findings, the results indicate that all areas exhibited significant changes except for the final cell count. Firstly, it is stated that “no statistically significant difference was observed in the cell population counts that were fixed the following inoculation immediately or during the acceleration phase between the spaceflight and Earth cultures” (Zea et al., 2017, p. 7). Thus, the total number of cells cultivated in space was not significantly different from that of the Earth’s counterpart colonies, which were grown while controlling for other factors. Secondly, the findings indicate that “the average volume of the spaceflight cells was 37% of the Earth controls” (Zea et al., 2017, p. 8). The main reason why each individual E. Coli cell was lower was due to diffusion proceeding less probabilistically. In other words, many cellular mechanisms rely on the diffusion of molecules to function, and since weightlessness slows and disrupts diffusion, bacteria could not have larger cells.
Thirdly, a significant expected change occurred in cell envelope thickness. It is stated that “the two experimental sets that could be directly compared indicate that E. Coli samples cultured in space exhibited an increased cell envelope thickness with respect to their matched Earth controls” (Zea et al., 2017, p. 8). The result contradicts the vast majority of previous findings, which reported no changes in cell envelope thickness. However, the authors object that the previous observations did not account for statistical significance, nor were their methods as advanced as those in this study (Zea et al., 2017). A notable change in E. Coli’s cell wall is likely a result of adaptive resistance to new space conditions. Cell walls serve the purpose of maintaining pressure between intracellular and extracellular forces. The lack of the latter means that a thicker cell wall is needed to counteract the sole intracellular pressure emanating from the inside of the cell.
Fourthly, unique vesicle formations were noted in E. Coli grown in space. It is stated that such vesicles contain misfolded proteins and other toxic material, which indicates that protein structure formation is partly reliant on the forces of gravity (Zea et al., 2017). In other words, space and weightlessness put an additional level of stress on cellular functionality, specifically on protein folding processes. Lastly, E. coli colonies were significantly clustered together, which was a notable difference in how the bacteria form aggregations on Earth (Zea et al., 2017). In other words, the bacteria clustered, clumped, and aggregated together more tightly, floating as a singular unit instead of forming biofilms or surface-attached colonies. This can be explained by the lack of gravity, which prevented them from structuring themselves as they would on Earth.
Overall, the significant results supported the hypothesis that changes would occur in cell size, cell ultrastructure, cell envelope thickness, and culture morphology, but the total cell count remained unchanged. The key technique involved using the same E. coli colonies to subject them to different conditions, such as space and Earth, while controlling all other factors. Some samples were treated with chemicals to test their resistance to toxicity in these different environments. Still, the core of the experiment was the assessment of the influence of space on bacterial growth and development.
Significance
The results are highly significant, as humans are also comprised of cells. Any dramatic changes in human cells due to weightlessness on a cellular level can lead to significant systemic changes across tissues, organs, and the entire body. The authors state that “this cell aggregation may be associated with enhanced biofilm formation reported on other spaceflight experiments and needs to be studied further to determine the cause and significance” (Zea et al., 2017, p. 10). Therefore, they call for future studies on the unique biofilm formation in space, as such structures are a significant cause of many respiratory diseases. Space travel can become substantially complicated if diseases can manifest themselves differently.
The article is significant because it offers insight into various aspects of space travel and exploration. Any change on a cellular level in E. coli is a cause for concern and research focus due to its potential impacts on human health, food, and sustenance, as well as post-space exposure recovery. The following steps should focus on analyzing each of these findings separately, using larger sample sizes, more suitable model organisms, and more precise methods.
Rationale
I chose this particular article to review because it was interesting and informative. Since space travel is a significant element of futurology and sci-fi, as well as modern scientific colonization goals, learning about how space affects living organisms is essential. In addition, the study is clearly written, and most of the descriptions, findings, and conclusions are presented in plain, non-complicated language. It is not surprising that one would consider the topic of space travel highly interesting, and identifying the connection of E. coli to such studies is both engaging and informative.
Conclusion
In conclusion, understanding the impacts and ramifications of being exposed to the weightless conditions of space is crucial in order to comprehend how cells, such as E. coli, adapt to such an environment. The findings indicate that cell size, cell envelope thickness, cell ultrastructure, and culture morphology exhibited significant changes; however, no alterations were noted in the final cell count. The researchers were able to identify cellular alterations in E. coli colonies exposed to space conditions as part of space flight missions.
References
General Services Administration & the Office of Management and Budget. (2021). National Aeronautics and Space Administration. Web.
Zea, L., Larsen, M., Estante, F., Qvortrup, K., Moeller, R., de Oliveira, S. D., Stodieck, L., & Klaus, D. (2017). Phenotypic changes exhibited by E. Coli cultured in space. Frontiers in Microbiology, 8(1598), 1-12. Web.