جداسازی و شناسایی مخمرهای لیپولیتیک از کنجاله کنجد استان یزد و بررسی پتانسیل تولید لیپاز در آن‌ها

Today, many studies are doing to identify the lipolytic microorganisms because of the important role of them in the production of microbial lipases. Oilseed meals are a good place to achieve these microorganisms. In this field, yeasts are more important in comparison with other microorganisms. In this study, we isolated 27 types of fungi from Yazd sesame meal. After the evaluation of macro and micro morphological features, it was identified that 16 of them were from yeast group. Lipolytic yeasts were screened using Tween 80 agar medium and were identified to genus and species by colony and cell morphology observations and evaluation of fermentation reactions and the use of carbon and nitrogen sources. 4 lipolytic screened yeasts were included Sporidiobolus pararoseus, Sporobolomyces salmonicolor, Cryptococcus albidus and Yarrowia lipolytica .The ratio of areola diameter to the well diameter was between 2.314 – 2.714. S. pararoseus showed the maximum ratio of areola to well diameter (2.714) .Lipase activity of these four types of yeasts was measured in submerged cultures with Cezepek Dox medium for 7 days at 30 °C and 200 rpm by using of photometry method and p-nitrophenyl palmitate substrate. Lipase activity range was between 0.866 – 4.333 U/ml, and Cryptococcus albidus had the highest lipase activity 4.333 U / ml, while it showed the least biomass growth among other yeasts (OD= 0.577). Yarrowia lipolytica showed lipase activity of 3.466 U/ml and also, the highest biomass growth OD =0.806.