evaluation of growth inhibit of food spoilage yeast of lactobacillus brevis and enterococcus faecium from “chal in iranian yoghurt drink (doogh)

anti-microbial effects of the lactic acid bacteria have been studied and proved in various investigations. this investigation aimed to study the anti-yeast effect of two isolated lactic acid bacteria species from “chal” (a product from yogurt) as biological preservatives in doogh. to do so, anti-yeast activity of l. brevis and e. faecium against saccharomyces cerevisiae, kluyveromyces. marxianus and rhodotorula glutinis was evaluated using the overlay method. besides, anti-yeast activity of these bacteria was assessed in yogurt samples containing the yeast. according to the results, l. brevis and e. faecium had strong prohibiting ability against r. glutinis ; however, they had no anti-yeast effect against s. cerevisiae and k. marxianus. statistical analysis revealed that, in contrast to the other two studied yeasts, content of the yeast r. glutinis decreased over 15 days of a logarithm cycle compared to the control. therefore, based on the results, lactic acid bacteria could be recommended as biological preservatives besides the common chemical preservatives