In Haday plant, about 1000e2000 bottles of soy sauce in some batches were found swelling and leaking. The total plate count of the swelling or leaking soy saucewas as low as 200e500 CFU/mL by traditional nutrient agar method, the flavor and pH of the soy sauce was normal, and there was no yeast or lactic acid bacteria detected in those swollen or leaking soy sauce bottles.
Furthermore, when non-contaminated bottled soy sauce was inoculated with bacteria