Lipid extraction directly from the wet oleaginous microorganisms for biodiesel production is preferred as it reduces the energy input for traditional processes which require extensive drying of the biomass prior to the extraction. The high water content (≥80% on cell dry weight) in the wet biomass hinders the extraction efficiency due to the mass transfer limitation. This limitation can be overcome by pretreating wet biomass prior to the lipid extraction using pressurized gas that can be used alone or combined with other pretreatments to disrupt the cell wall. In this review, an extensive discussion on different pretreatments and the subsequent lipid extraction using these pretreatments is presented. Furthermore, a detailed account of the cell disruption using pressurized gas (e.g., CO₂) treatment for microbial cell lysing is also presented. Finally, a new technique on lipid extraction directly from wet biomass using the combination of pressurized CO₂ and microwave pretreatment is proposed.

直接从湿的油质微生物中进行脂质提取以生产生物柴油是优选的，因为它减少了传统方法的能量输入，而传统方法需要在提取之前大量干燥生物质。由于传质的限制，湿生物质中的高水分含量（≥80％的细胞干重）阻碍了萃取效率。通过在脂质提取之前使用加压气体对湿生物质进行预处理，可以克服这一局限，加压气体可以单独使用，也可以与其他预处理结合使用以破坏细胞壁。在这篇综述中，提出了关于不同预处理以及随后使用这些预处理进行脂质提取的广泛讨论。此外，使用加压气体（例如，CO ₂还提出了用于微生物细胞裂解的治疗方法。最后，提出了一种利用加压CO ₂和微波预处理相结合直接从湿生物质中提取脂质的新技术。