Solvent extraction of bacteriocins from liquid ... - Wiley Online Library

Letters in Applied Microbiology 2000, 31, 193ÿ197

Solvent extraction of bacteriocins from liquid cultures L.L. Burianek and A.E. Yousef Department of Food Science and Technology, The Ohio State University, Columbus, OH, USA 508/2000: received 12 January 2000, revised 17 April 2000 and accepted 25 May 2000

A solvent extraction method was developed to concentrate lacidin from the culture of Lactobacillus acidophilus OSU133. The new method concentrates the bacteriocin at the interface between chloroform and the aqueous culture of the producing bacterium. Compared with other extraction procedures, the new method effectively recovers higher bacteriocin yield and results in relatively clean preparations. Recovery of lacidin by the chloroform extraction procedure, compared with ammonium sulphate precipitation and cell acidi®cation methods, was >10-fold and about 100-fold greater, respectively. The new extraction procedure saves time and is easy to perform. This method is also effective in recovering subtilin, bacillicin, pediocin and nisin from cultures of Bacillus subtilis ATCC 6633, B. subtilis OSY1115/C, Pediococcus acidilactici PO2 and Lactococcus lactis ATCC 11454, respectively.

L . L . B U R I A N E K A N D A . E . Y O U S E F . 2000.

INTRODUCTION

Tagg et al. (1976) de®ned bacteriocin as the bacterial substance which has an essential, biological protein moiety and a bactericidal mode of action centred against the homologous species. Chemical analyses indicate that some bacteriocins, including certain staphylococcal, clostridal and lactobacillus bacteriocins, are quite complex molecules with lipid and carbohydrate components in addition to protein, while others are simple proteins. Bacteriocins of lactic acid bacteria (LAB) are particularly important because of the essential role of these bacteria in the majority of fermented foods. Klaenhammer (1993) classi®ed bacteriocins of LAB into four groups: (I) lantibiotics, small (