School of Resources, Environment and Materials, Guangxi University, Nanning, Guangxi 530004, China; Guangxi Key Laboratory of Electrochemical Energy Materials, Nanning, Guangxi 530004, China.
School of Resources, Environment and Materials, Guangxi University, Nanning, Guangxi 530004, China.
Sci Total Environ. 2022 Feb 1;806(Pt 3):151387. doi: 10.1016/j.scitotenv.2021.151387. Epub 2021 Nov 2.
Energy is a major driving force for the economic development. Due to the scarcity of fossil fuels and negative impact on the environment, it is important to develop renewable and sustainable energy sources for humankind. Microalgae as the primary feedstock for biodiesel has shown great application potential. However, lipid yield from microalgae is limited by the upstream cost, which restrain the realization of large-scale biofuel production. The modification of lipid-rich microalgae cell has become the focus over the last few decades to improve the lipid content and productivity of microalgae. Carbon is a vital nutrient that regulates the growth and metabolism of microalgae. Different carbon sources are assimilated by microalgae cells via different pathways. Inorganic carbon sources are mainly used through the CO-concentrating mechanisms (CCMs), while organic carbon sources are absorbed by microalgae mainly through the Pentose Phosphate (PPP) Pathway and the Embden-Meyerhof-Pranas (EMP) pathway. Therefore, the addition of carbon source has a significant impact on the production of microalgae biomass and lipid accumulation. In this paper, mechanisms of lipid synthesis and carbon uptake of microalgae were introduced, and the effects of different carbon conditions (types, concentrations, and addition methods) on lipid accumulation in microalgal biomass production and biodiesel production were comprehensively discussed. This review also highlights the recent advances in microalgae lipid cultivation with large-scale commercialization and the development prospects of biodiesel production. Current challenges and constructive suggestions are proposed on cost-benefit concerns in large-scale production of microalgae biodiesel.
能源是经济发展的主要驱动力。由于化石燃料的稀缺性和对环境的负面影响，开发可再生和可持续的能源对于人类来说非常重要。微藻作为生物柴油的主要原料，具有巨大的应用潜力。然而，微藻的产油率受到上游成本的限制，这限制了大规模生物燃料生产的实现。因此，在过去几十年中，人们一直致力于对富脂微藻细胞进行修饰，以提高微藻的脂质含量和生产力。
碳是一种重要的营养物质，它调节微藻的生长和代谢。不同的碳源通过不同的途径被微藻细胞同化。无机碳源主要通过 CO2 浓缩机制（CCMs）被利用，而有机碳源主要通过戊糖磷酸（PPP）途径和 EMP 途径被微藻吸收。因此，碳源的添加对微藻生物量的生产和脂质积累有显著影响。
本文介绍了微藻的脂质合成和碳吸收机制，并综合讨论了不同碳条件（类型、浓度和添加方法）对微藻生物量生产和生物柴油生产中脂质积累的影响。本文还重点介绍了微藻脂质大规模商业化培养的最新进展和生物柴油生产的发展前景。针对微藻生物柴油大规模生产的成本效益问题，提出了当前的挑战和建设性建议。
