Escherichia coli (e coli) is a gram-negative bacteria that is a rod-shaped bacterium and is commonly found in the intestines of humans and animals. The bacteria are motile and non-spore-forming as well as facultative anaerobic. E. coli is a common part of bacterial flora. The bacteria are primarily found in the lower intestines of warm-blooded animals (“E. coli,” 2018). Most of the strains are not harmful but there are strains of E. coli such as 0157: H7, 0104: H4, 0121, and others that are harmful and can cause foodborne diseases. One of the most common strains of E. coli bacteria which are harmful is Shiga toxin-producing E. coli (STEC) which is a group of strains that are producing toxins leading to several diseases in humans. E. coli is being transferred from the consumption of contaminated food such as uncooked and raw food. Fecal contamination of the vegetable and other contaminated raw foods can contain STEC resulting in acute and severe illness in humans, especially in children and young adults. Because STEC is heat sensitive so by cooking the food properly this bacteria and its impact can be avoided.
Desulfosarcina variabilis (D. variabilis) is sulfate-reducing bacteria and this bacteria is also a part of the δ-proteobacteria. The bacteria does not have any specific shapes as they are irregular in shapes including rods, teardrops, ovals, and some other shapes. Desulfosarcina variabilis is a group II sulfate-reducing bacteria because it utilizes acetates and another fatty acid ultimately oxidizing them. This sulfate-reducing bacteria is because D. variabilis contains AEG-P (top) along with a 20% alkyl-glycerol bond as DPG lipids (“Desulfosarcina,” 2010). D. variabilis is a mesophilic bacteria containing different lipid components. The bacteria are primarily non-motile and produce granules within the cells. The bacteria are usually present in the water and marine environment anaerobic in nature. Even though Sulfate reduction is an anaerobic process still sulfate-reducing bacteria (SRB) are also an essential part of the aerobic environment.
Microbial life on Mars:
Since humans have landed on Mars there has been a debate about whether life exists on Mars or the signs of the existence of any microbial life. After several experiments and research by scientists, the experiment by Viking Labeled Release (LR) in the year 1976 found a positive result that there is an existence of microbial life on Mars (Levin & Straat, 2016; Mary Ann Liebert, Inc., Publishers, 2016). However, there are several researchers who oppose the results because according to them the environment on Mars is harsh and extreme for the survival of any living organisms. Scientists have been conducting an experiment to find out whether the microbe can survive on the surface of Mars given the environmental conditions such as temperature. The environment of Mars is dry with 95% carbon dioxide and the surface of Mars is rocky. A study has concluded that 31 different species of bacteria from Earth can grow on Mars with some specific conditions (David, 2017). Also, the surface of Mars does not have an environment favorable for bacteria because the surface is too cold and dry and bacteria require a warm environment for growth. The two approaches for the investigation of microbial life that exists on Mars would be researched by creating a mock Recurring Slope Lineae (RSL) chamber because the RSL chamber can only resist the liquid water environment at Mars. Another option is putting salt or ice crystal near the surface of Mars which can capture the environment and another habitat in that environment.