Kot Anna M, Gientka Iwona, Bzducha-Wróbel Anna, Błażejak Stanisław, Kurcz Agnieszka
Department of Food Biotechnology and Microbiology, Institute of Food Sciences, Warsaw University of Life Sciences, Nowoursynowska 159C, 02-776 Warsaw, Poland.
Department of Food Biotechnology and Microbiology, Institute of Food Sciences, Warsaw University of Life Sciences, Nowoursynowska 159C, 02-776 Warsaw, Poland.
J Microbiol Methods. 2020 Sep;176:105999. doi: 10.1016/j.mimet.2020.105999. Epub 2020 Jul 11.
The present study examined the effect of six disruption methods of the cell wall (acid hydrolysis, ultrasonication, osmotic shock, pasteurization, homogenization with zirconia balls, and freezing/defrosting) on the efficiency of lipid extraction from yeast cells and the composition of fatty acids. Acid hydrolysis and sonication led to a significant increase in lipid extraction from Cyberlindnera jadinii ATCC 9950 and Rhodotorula glutinis LOCKR13 yeast cells. The amount of lipids extracted in these conditions increased for C. jadinii from 12.46 (biomass not subjected to any pretreatment) to 20.37 and 19.53 g/100 g after the application of acid hydrolysis and sonication, respectively, and for R. glutinis strain from 13.95 to 21.20 and 17.22 g/100 g, respectively, for the same methods. Initial sonication of biomass led to a significant reduction in the percentage of unsaturated fatty acids. The largest differences in fatty acid composition were found for the sample homogenized with zirconium balls. This process resulted in the degradation of both oleic acid and linolenic acid. The obtained results revealed that the method that significantly increases lipid extraction and does not change the composition of fatty acids is acid hydrolysis with hydrochloric acid. In addition, it is easy, cheap, does not require specialized equipment, and therefore can be implemented in any laboratory.
本研究考察了六种细胞壁破坏方法（酸水解、超声处理、渗透休克、巴氏杀菌、用氧化锆球匀浆以及冷冻/解冻）对从酵母细胞中提取脂质的效率和脂肪酸组成的影响。酸水解和超声处理使从季也蒙毕赤酵母ATCC 9950和粘红酵母LOCKR13酵母细胞中提取的脂质显著增加。在这些条件下，季也蒙毕赤酵母提取的脂质量分别在酸水解和超声处理后从12.46（未进行任何预处理的生物量）增加到20.37和19.53 g/100 g，对于粘红酵母菌株，相同方法下提取的脂质量分别从13.95增加到21.20和17.22 g/100 g。生物量的初始超声处理导致不饱和脂肪酸百分比显著降低。在用锆球匀浆的样品中发现脂肪酸组成的差异最大。这个过程导致油酸和亚麻酸都降解。所得结果表明，显著增加脂质提取且不改变脂肪酸组成的方法是用盐酸进行酸水解。此外，它简单、便宜，不需要专门设备，因此可以在任何实验室实施。
