Swiss Cheese Niche: Difference between revisions
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Do they ferment sugars to produce acid, break down large molecules, fix nitrogen, etc. etc. | Do they ferment sugars to produce acid, break down large molecules, fix nitrogen, etc. etc. | ||
Lactobacillus ferments lactose into lactic acid. Also among fermentation lactobacillus also has other metabolism such as | |||
==Current Research== | ==Current Research== | ||
Revision as of 08:12, 28 August 2008
Description of Niche
Where located?
Physical Conditions?
What are the conditions in your niche? Temperature, pressure, pH, moisture, etc.
Influence by Adjacent Communities (if any)
Is your niche close to another niche or influenced by another community of organisms?
Conditions under which the environment changes
Do any of the physical conditions change? Are there chemicals, other organisms, nutrients, etc. that might change the community of your niche.
Who lives there?
Which microbes are present?
You may refer to organisms by genus or by genus and species, depending upon how detailed the your information might be. If there is already a microbewiki page describing that organism, make a link to it.
Within the Swiss Cheese environment lives three types of microbes of the genus lactobacillus, streptococcus, and propionibacteria.
Lactobacillus is a homofermentative and gram-positive bacteria that is always found within Swiss cheese due to its ability to provide texture and sharpness of the cheese. Different types of strains of lactobacillus(L. helveticus, L. casei, L. bulgaricus) live in Swiss cheese but the more commonly known bacteria is the strain lactobacills helveticus. This microbe is part of the lactic acid family of bacteria by converting lactose present in the cheese to lactic acid. [1]
Do the microbes that are present interact with each other?
Describe any negative (competition) or positive (symbiosis) behavior
Lactobacillus helveticus is mainly involved with Streptococcus thermophilus in controlling the pH level of the Swiss cheese environment through their fermentation of lactose. The Swiss cheese enivronment changes temperatures due to the pastuerization process and in its intial stages Streptococcus thermophilus is the more dominant bacteria in the cheese. However since makers of Swiss cheese allow it to sit at room temperature for the ripening process allows for the growth of lactobacillus helveticus. Since room temperature is slightly off from the optimum growth temperature for lactobacillus helveticus, the microbe is slowly able to grow. When L. helveticus reaches its maximum growth or reaches the stationary phase it begins to lyse and starts to affect the viability of Streptococcus thermophilus. There is correlation between the survivability of Lactobacillus and Streptococcus but there are no specifics as to why the correlations occur. [2]
Do the microbes change their environment?
Do they alter pH, attach to surfaces, secrete anything, etc. etc.
Lactobacillus alter the pH by fermenting the lactose that surrounds them and converting it into lactic acid. In addition to changing their environment Lactobacillus can also produce formation of lactate calcium crystals and toxic amines. The lactate calcium crystals form on the surfaces on the cheese and has no adherent effects on the Lactobacillus and is just a defect within the cheese environment. No information or study has been found yet on how the production of toxic amines would affect the surrounding microbes of Streptococcus and Propionibacteria but was more commonly known as an outbreak of food poisoning when ingested by humans. [3]
Do the microbes carry out any metabolism that affects their environment?
Do they ferment sugars to produce acid, break down large molecules, fix nitrogen, etc. etc.
Lactobacillus ferments lactose into lactic acid. Also among fermentation lactobacillus also has other metabolism such as
Current Research
Enter summaries of the most recent research. You may find it more appropriate to include this as a subsection under several of your other sections rather than separately here at the end. You should include at least FOUR topics of research and summarize each in terms of the question being asked, the results so far, and the topics for future study. (more will be expected from larger groups than from smaller groups)
References
Edited by , students of Rachel Larsen
