Another requirement of bacteria to survive is Neutral PH.
Most bacteria are neutrophiles, meaning they grow optimally at a pH within one or two pH units of the neutral pH of 7. Most familiar bacteria, like Escherichia coli, staphylococci, and Salmonella spp. are neutrophiles and do not fare well in the acidic pH.
Because of its acetic acid content and low pH, vinegar is used as food preservative. It is in fact used for the preservation, pickling of a wide variety of foods such as vegetables, meat, fish products, and fruits.