Identification and evaluation of antibacterial agents produced by microorganisms in local raw bioproducts

Abstract

Microorganisms with a wide range of antibacterial activity can be an effective tool dealing with pathogenic and food spoilage bacteria. Depending on the environment, microorganisms adapt, resulting in different strains that can produce antibacterial substances with different properties. Such substances are bacteriocins, produced by lactic acid bacteria and killer toxins, produced by yeast [1,2]. These materials are widely investigated in medicine and veterinary medicine as narrow-spectrum antibiotics. Bacteriocins and killer toxins are also important in food industry because microorganisms which produce them are non-pathogenic and normally colonize the human body [3]. The aim of this work is to find lactic acid bacteria and yeast which have antibacterial activity in local raw materials such as sour milk, whey and bee bread. All isolated bacteria were preliminary identified based on their staining by Gram and catalase tęst. The antibacterial activity of all isolated microorganisms using S. aureus, E. coli, M. luteus and P. vulgaris strains was determined by agar well diffusion method. Lactic acid bacteria which were isolated from sour milk showed antibacterial activity against all tested pathogenic bacteria and bacteria isolated from whey showed antibacterial activity against P. vulgaris and M. luteus. Detailed results of the work will be presented during the conference.