Abstract:

Biodiesel produced by microbial oils is a renewable alternative energy of traditional fossil fuels, and oleaginous yeasts are promising oleaginous microorganisms. Glucose is the most widely studied carbon source of oleaginous yeasts, however, its cost is too high to develop its large-scale applications. Thus, it is crucial to develop low-cost carbon source. Based on analyzing the metabolic mechanism of lipid synthesis of oleaginous yeasts, this article focuses on the advances of four cheap raw materials utilized by oleaginous yeasts: lignocellulose, crude glycerol, organic wastewater, and volatile fatty acids to synthesize microbial lipids. The enhancement or inhibition of the complicated components of these industrial and agricultural by-products on the cell growth and lipid synthesis of oleaginous yeast are discussed respectively. Subsequently, feasible solutions, such as efficient pretreatment of raw materials, genetic engineering to modify yeast, and co-culture with microorganisms are summarized. Finally, the advantages of oleaginous yeast utilizing low-cost substrates to synthesize lipids are clarified, solutions to conquer the inhibition of complicated components and high organic matter concentrations are proposed, and the future research is prospected. This review is beneficial to further promote the applications of low-cost substrates for oleaginous yeast to synthesize lipids and the development of renewable energy technologies.

Key words: biodiesel, microbial oils, oleaginous yeast, low-cost substrates, metabolism pathway, renewable energy

摘要：

利用微生物油脂生产的生物柴油是替代传统化石燃料的绿色可再生能源，产油酵母是极具潜力的产油微生物。然而利用葡萄糖作为碳源成本较高，限制了微生物油脂合成技术的规模化应用，因而寻找廉价原料至关重要。本文基于产油酵母合成油脂的代谢机理，重点介绍了产油酵母利用4种廉价原料，即木质纤维素、粗甘油、有机废水和挥发性脂肪酸合成微生物油脂的研究进展。针对这些来自工农业副产物的廉价原料，分别讨论了其复杂成分对产油酵母生长和油脂合成产生的促进或抑制作用，分析总结了高效预处理、基因工程改造菌体以及微生物共培养等解决方案。通过以上分析，阐明了产油酵母利用廉价原料合成油脂的优点，提出了针对复杂成分和高有机质浓度的抑制性问题的解决方法，理清了未来研究的方向，有助于进一步推动廉价原料用于产油酵母生产油脂及可再生能源技术的发展。

关键词: 生物柴油, 微生物油脂, 产油酵母, 廉价原料, 代谢途径, 再生能源