This study was undertaken to investigate the antifungal effect of DL-limonene on yeasts using disk diffusion and the minimum inhibitory concentration (MIC). The effect of DL-limonene on ethyl alcohol fermentation by Saccharomyces cerevisiae was also investigated. | Research Article Turk J Agric For 36 (2012) 576-582 © TÜBİTAK doi: Research on antifungal and inhibitory effects of DL-limonene on some yeasts Mustafa Ümit ÜNAL1,*, Filiz UÇAN1, Aysun ŞENER1, Sadık DİNÇER2 1 Department of Food Engineering, Faculty of Agriculture, Çukurova University, Adana - TURKEY 2 Department of Biology, Faculty of Science and Letters, Çukurova University, Adana - TURKEY Received: ● Accepted: Abstract: This study was undertaken to investigate the antifungal effect of DL-limonene on yeasts using disk diffusion and the minimum inhibitory concentration (MIC). The effect of DL-limonene on ethyl alcohol fermentation by Saccharomyces cerevisiae was also investigated. According to disk diffusion results, the development of an inhibition zone was observed in all microorganisms tested. The inhibition zones were larger than those occurring with the Fungizone antibiotic used as the control. Inhibition zone diameters increased with increasing amounts of DL-limonene. MIC results varied between 500 and 4000 μg mL−1 depending on the yeast strain. DL-limonene at a concentration of (w v−1) inhibited cell growth, ethanol formation, and sugar utilization by S. cerevisiae. Key words: Antifungal effect, DL-limonene, fermentation, yeasts Introduction Since the Middle Ages, essential oils have been widely used in bactericidal, virucidal, fungicidal, antiparasitic, insecticidal, medicinal, and cosmetic applications. Because of the mode of extraction, generally distillation from aromatic plants, these oils contain a variety of volatile molecules such as terpenes and terpenoids, phenol-derived aromatic components, and aliphatic components (Bakkali et al. 2008). The essential oils of plants show antimicrobial activity against a wide range of bacteria, including antibiotic-resistant species and fungal species. They can affect both gram-positive and gram-negative bacteria in addition to yeasts and filamentous .
