Hanqin Chen1,2, Haiqin Chen3,4, Hengqian Lu1,2, Xin Tang1,2, Hao Zhang1,2,5,6, Yong Q Chen1,2,5,6, Wei Chen1,2,5,7. 1. State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, Jiangsu, People's Republic of China. 2. School of Food Science and Technology, Jiangnan University, Wuxi, 214122, Jiangsu, People's Republic of China. 3. State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, Jiangsu, People's Republic of China. haiqinchen@jiangnan.edu.cn. 4. School of Food Science and Technology, Jiangnan University, Wuxi, 214122, Jiangsu, People's Republic of China. haiqinchen@jiangnan.edu.cn. 5. National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, 214122, Jiangsu, People's Republic of China. 6. Wuxi Translational Medicine Research Center and Jiangsu Translational Medicine Research Institute Wuxi Branch, Wuxi, 214122, Jiangsu, People's Republic of China. 7. Beijing Innovation Centre of Food Nutrition and Human Health, Beijing Technology and Business University (BTBU), Beijing, 100048, People's Republic of China.
Abstract
OBJECTIVES: To establish reliable methods for the extraction and quantification of the total carbohydrate and intracellular saccharides from Mortierella alpina and study the changes between carbohydrate and lipid in fermentation process. RESULTS: The extraction of mycelia with HCl following a photometric phenol-sulphuric acid reaction was identified as an optimal method for total carbohydrate analysis in Mortierella alpina, which the extraction efficiency performed 1.1-3.6 fold than other five methods. The total carbohydrate content increased from initial 19.26 to 25.86% during early fermentation process and declined gradually thereafter, while the fatty acid was increasing from 8.47 to 31.03%. For separation and qualitative estimation of intracellular saccharides, the acetonitrile/water freeze-thaw method for extraction and Sugar-Pak I column for separation proved to be possible. With the glucose rapidly decreasing at the beginning of growth, the trehalose accumulated rapidly from 1.63 to 5.04% and then decreased slightly but maintain above 4% of dry biomass. CONCLUSIONS: This work established comprehensive carbohydrate extraction and analysis methods of Mortierella alpina and identified the main saccharide in fermentation process which indicated that the accumulation of fatty acids was related to the change of intracellular carbohydrate content.
OBJECTIVES: To establish reliable methods for the extraction and quantification of the total carbohydrate and intracellular saccharides from Mortierella alpina and study the changes between carbohydrate and lipid in fermentation process. RESULTS: The extraction of mycelia with HCl following a photometric phenol-sulphuric acid reaction was identified as an optimal method for total carbohydrate analysis in Mortierella alpina, which the extraction efficiency performed 1.1-3.6 fold than other five methods. The total carbohydrate content increased from initial 19.26 to 25.86% during early fermentation process and declined gradually thereafter, while the fatty acid was increasing from 8.47 to 31.03%. For separation and qualitative estimation of intracellular saccharides, the acetonitrile/water freeze-thaw method for extraction and Sugar-Pak I column for separation proved to be possible. With the glucose rapidly decreasing at the beginning of growth, the trehalose accumulated rapidly from 1.63 to 5.04% and then decreased slightly but maintain above 4% of dry biomass. CONCLUSIONS: This work established comprehensive carbohydrate extraction and analysis methods of Mortierella alpina and identified the main saccharide in fermentation process which indicated that the accumulation of fatty acids was related to the change of intracellular carbohydrate content.