A review on microbial lipids conversion from organic wastes: Adaptive laboratory evolution-driven strategies for...

The strategic conversion of fermentation effluents from organic waste into microbial lipids for biofuel production has emerged as a key strategy for advancing sustainable development. However, inhibitory components in fermentation broths substantially impair the metabolism of oleaginous microbes, critically compromising bioconversion efficiency. Traditional pretreatment methods, such as chemical and enzymatic approaches, incur additional costs. Adaptive Laboratory Evolution (ALE) technology is based on the principle of directed evolution, precisely constructs biological stress environments and reshapes microbial metabolic networks to enhance strain tolerance and functionality. This enables the direct utilization of complex fermentation broths for lipid production. This paper first introduces the mechanism of selective pressure exerted by the ALE technique, and proposes strategies for nutrient supply and extreme environmental stress based on the physiological characteristics of strains. It then focuses on the technical principles of the ALE process, with a key discussion on the different evolutionary modes of ALE and their applicable scenarios. Building on this foundation, this review introduces novel integrative strategies bridging ALE and synthetic biology, employing precision metabolic engineering, genomic editing and machine learning to expand the application boundaries of ALE technology. Finally, the future development trends of ALE technology in the field of organic waste resource utilization are systematically explored in this review.