Taskin, MesutUcar, Muhammed HanifiUnver, YagmurKara, Ayse AydanOzdemir, MustafaOrtucu, Serkan2026-03-262026-03-2620161878-818110.1016/j.bcab.2016.08.0092-s2.0-84983394296https://doi.org/10.1016/j.bcab.2016.08.009https://hdl.handle.net/20.500.14901/2153Taskin, Mesut/0000-0002-9350-9628; Örtücü, Serkan/0000-0002-3180-0444; Unver, Yagmur/0000-0003-1497-081XThis study was undertaken to produce the lipase by free and immobilized cells of cold-adapted yeast Rhodotorula glutinis HL25 using waste frying oils as substrate. The optimization of culture parameters was performed using traditional one-factor-at-a-time protocol. The temperature 20 degrees C and initial pH 6.0 were optimal for lipase production by both free and immobilized cells. An inoculum size of 40 mL/L for free cells and beads number of 150 g/L for immobilized cells were optimal for lipase production. Optimal waste frying oil concentration and incubation time were 30 mL/L and 84 h for free cells but 40 mL/L and 72 h for immobilized cells, respectively. The maximum increases for free and immobilized cells were achieved at the Triton X-100 concentrations of 5 and 7.5 mL/L, respectively. The maximum lipase activities were determined as 54.4 and 75.2 U/L for free and immobilized cells, respectively. Immobilized cells could be used in five successive reaction cycles without any loss in the maximum activity. Immobilized cells could retained about 70% of their maximum activity by the end of the cycle 10. This is the first attempt on lipase production potential of a cold-adapted strain of the yeast R. glutinis. Furthermore, lipase production using immobilized cells of cold-adapted yeasts was investigated for the first time. (C) 2016 Elsevier Ltd. All rights reserved.eninfo:eu-repo/semantics/closedAccessRhodotorula GlutinisCold-AdaptedLipaseImmobilized CellsProductionArticle