Inhibition of Bacillus licheniformis LMG 19409 from ropy cider by enterocin AS-48

Abstract

Aims: To determine the activity of enterocin AS-48 against ropy-forming Bacil-lus licheniformis from cider.Methods and Results: Enterocin AS-48 was tested on B. licheniformis LMG19409 from ropy cider in MRS-G broth, fresh-made apple juice and in twocommercial apple ciders (A and B). Bacillus licheniformis was rapidly inacti-vated in MRS-G by 0Æ5 lg ml)1 AS-48 and in fresh-made apple juice by3 lg ml)1 . Concentration-dependent inactivation of this bacterium in twocommercial apple ciders (A and B) stored at 4, 15 and 30°C for 15 days wasalso demonstrated. Counts from heat-activated endospores in cider A plusAS-48 decreased very slowly. Application of combined treatments of heat(95°C) and enterocin AS-48 reduced the time required to achieved completeinactivation of intact spores in cider A to 4 min for 6 lg ml)1 and to 1 minfor 12 lg ml)1 . D and z values also decreased as the bacteriocin concentrationincreased.Conclusion: Enterocin AS-48 can inhibit ropy-forming B. licheniformis in applecider and increase the heat sensitivity of spores.Significance and Impact of the Study: Results from this study support thepotential use of enterocin AS-48 to control B. licheniformis in apple cider.