In order to produce vinegar, acetobacter strains are used: they metabolize wine ethanol to acetic acid that gives vinegar its sour-refreshing taste, and keeps other critters at bay due to its acidity.
what was the original ecology of acetobacter?

The original ecology of Acetobacter is Saprobiont .

Explanation:

Those organisms which can digest the food externally so as to captivate the product. These are also known as the decomposers. Perhaps not the detritivores that abstract the food internally. These are more exploited for industrial application, as known to be good source of extra cellular enzymes. denitrification is carried out by these bacteria. The complex molecules were broken down by the enzymes into smaller molecules that are also soluble in nature . Through diffusion these organism absorb the molecules.  

the correct answer is d