|MadSci Network: Microbiology|
This is a good question. You have seen the other response from Chris Yost regarding pickle production. As he said there are two methods to make pickles, one is the fermentation method using the Lactobacillus where the bacteria produces lactic acid to acidify the pickles, and the other is to acidify the pickles with acetic acid or vinegar. The different acids will give some different flavors, and the two types of pickles may vary in texture as well. So, depending on the final product you want, this will determine the method to use. Most commercial pickles are acidified with vinegar. The fermentation process can be tricky and subject to spoilage organisms if conditions are not just right.
Now, more on the Lactobacillus. This is a genus of bacteria that are Gram positive rods found naturally in plant and animal material. This genus of bacteria contains species that are useful for fermentation processes, but also species responsible for food spoilage. In the food fermentations they produce lactic acid. Some products fermented by lactobacilli include pickles, sauerkraut, olives, sourdough bread and fermented sausages. Some foods spoiled by lactobacilli include sausages where the lactobacilli form a green discoloration, vacuum packaged meat which becomes sour due to lactic acid production, sugar cane which becomes slimy from Lactobacillus growth, and even fermented vegetables may be spoiled by different species of Lactobacillus. Examples of this spoilage are slimy sauerkraut and bloated cucumbers. Lactobacilli can also spoil catsup and mayonnaise by producing lactic acid in these acetic acid based products.
I hope that answers the question you had.
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