Matouk AbdAllah M, Abu-Elreesh Gadallah M, Abdel-Rahman Mohamed Ali, Desouky Said E, Hashem Amr H
Botany and Microbiology Department , Faculty of Science, Al-Azhar University, Nasr City, Cairo, 11884, Egypt.
Engineering and Biotechnology Research Institute (GEBRI), City of Scientific Research and Technological Applications (SRTA-City), New Borg Al-Arab City, Alexandria, 21934, Egypt.
Microb Cell Fact. 2025 Jan 10;24(1):16. doi: 10.1186/s12934-024-02635-3.
Oleaginous yeasts are considered promising sources for lipid production due to their ability to accumulate high levels of lipids under appropriate growth conditions. The current study aimed to isolate and identify oleaginous yeasts having superior ability to accumulate high quantities of lipids; and enhancing lipid production using response surface methodology and repeated-batch fermentation. Results revealed that, twenty marine oleaginous yeasts were isolated, and the most potent lipid producer isolate was Candida parapsilosis Y19 according to qualitative screening test using Nile-red dye. Orange peels was used as substrate where C. parapsilosis Y19 produced 1.14 g/l lipids at 23.0% in batch fermentation. To enhance the lipid production, statistical optimization using Taguchi design through Response surface methodology was carried out. Total lipids were increased to 2.46 g/l and lipid content increased to 30.7% under optimal conditions of: orange peel 75 g/l, peptone 7 g/l, yeast extract 5 g/l, inoculum size 2% (v/v), pH 5 and incubation period 6 d. Furthermore, repeated-batch fermentation of C. parapsilosis Y19 enhanced lipid production where total lipids increased at 4.19 folds (4.78 g/l) compared to batch culture (before optimization). Also, the lipid content was increased at 1.7 folds (39.1%) compared to batch culture (before optimization). Fatty acid profile of the produced lipid using repeated-batch fermentation includes unsaturated fatty acids (USFAs) at 74.8% and saturated fatty acids (SFAs) at 25.1%. Additionally, in repeated-batch fermentation, the major fatty acid was oleic acid at 45.0%; followed by linoleic acid at 26.0%. In conclusion, C. parapsilosis Y19 is considered a promising strain for lipid production. Also, both statistical optimizations using RSM and repeated-batch fermentation are efficient methods for lipid production from C. parapsilosis Y19.
由于产油酵母在适宜生长条件下能够积累高水平的脂质，因此被认为是脂质生产的有前途的来源。当前的研究旨在分离和鉴定具有卓越脂质积累能力的产油酵母；并使用响应面法和重复批次发酵来提高脂质产量。结果显示，分离出了20株海洋产油酵母，根据使用尼罗红染料的定性筛选试验，最有效的脂质生产菌株是近平滑假丝酵母Y19。在分批发酵中，以橙皮为底物，近平滑假丝酵母Y19产生了1.14 g/l脂质，脂质含量为23.0%。为了提高脂质产量，通过响应面法使用田口设计进行了统计优化。在以下最佳条件下：橙皮75 g/l、蛋白胨7 g/l、酵母提取物5 g/l、接种量2%（v/v）、pH 5和培养期6天，总脂质增加到2.46 g/l，脂质含量增加到30.7%。此外，近平滑假丝酵母Y19的重复批次发酵提高了脂质产量，与分批培养（优化前）相比，总脂质增加了4.19倍倍（4.78 g/l）。而且，与分批培养（优化前）相比，脂质含量增加了1.7倍（39.1%）。使用重复批次发酵生产的脂质的脂肪酸谱包括74.8%的不饱和脂肪酸（USFAs）和25.1%的饱和脂肪酸（SFAs）。此外，在重复批次发酵中，主要脂肪酸是油酸，含量为45.0%；其次是亚油酸，含量为26.0%。总之，近平滑假丝酵母Y19被认为是一种有前途的脂质生产菌株。而且，使用响应面法的统计优化和重复批次发酵都是从近平滑假丝酵母Y19生产脂质的有效方法。
