Lactobacillus Bulgaricus vs E.Coli - Essay Example

Effect of a microorganism or virulence of a bacterium may be caused by an organism being physically present in the host where it releases toxins to the host directly or its preformed toxins get into another organism’s body system through various routes such ingestion, skin etc. The virulence of microorganisms varies across genus as well as species. In this paper, I am going to describe two bacteria, explain their ecological niche, and finally compare them. Selection of bacteria After a thorough evaluation of bacteria I have rested on Escherichia coli and Lactobacillus bulgaricus.

The reason for selecting the two organisms is that they share a common feature of exhibiting a rectangular shape but their behaviors are totally different. Their similarities and differences are expounded below. Lactobacillus bulgaricus Lactobacillus bulgaricus’ is a non pathogenic organism. It occurs in its natural environment and its ecological niche is where there is its requirements for growth are provided especially in dairy products that contain lactose. It is chemoorganotrophic meaning that it must obtain energy and carbon from organic compounds.

It is a rod shaped and the rods join end to end to form a filamentous structure that are extensively long. This bacterium is a gram positive facultative anaerobe. Based on this fact, Lactobacillus bulgaricus can be homofermenative or heterofermentative. When it comes to motion, the bacterium is non motile because it does not possess locomotion. When conditions become unfavorable this particular bacterium does not form a spore. According to Guchte (2006) its size based on its shape ranges between 0.5-0.8 x 2.0-9.0mm.

For this bacterium to grow it requires a medium whose pH ranges between 4.6 -5.4 (Guchte, 2006). The fact that it can only hydrolyse lactose sugar makes it quite important to food industry because of its by-products. When it is fed with lactose, the bacterium converts this sugar to lactic acid. This fact has been exploited as a principle in yoghurt production where lactose in milk in converted to lactic acid and it is used as a preservative as well as well as giving the yoghurt an awesome a tart flavor.

The bacterium reproduces asexually through conjugation. Conjugation is a process where RNA and DNA are transferred from one bacterium to another (PBWorks, 2008). Lactobacillus bulgaricus can also be found in human intestines. Escherichia coli This bacterium occurs in the natural environment particularly fecal contaminated one but it carves its niche in the lower part of intestines of organisms that are warm blooded because there is a well balanced ecosystem. In the intestines there are specific nutrients that are provided and conditions are favorable for its growth and survival.

Some strains of this bacterium especially O111, O145, O104:H21, O157:H7, O121, O104:H4, O26, and O103 are very pathogenic (Nicole et al., 2001). About 0.1% of the bacteria that colonize mammalian gut belong to the E. coli specie (Nicole et al., 2001). The bacterium is a gram negative rod and it is a facultative anaerobe whose cell measures approximately 2.0 x 0.5µm (Nicole et al., 2001). When this bacterium is outside the host’s body, it is able to survive for some period of time which has made it to be used as indicator of