Microalgal-based biofuel replaces fossil fuel to meet the current global energy demand. The mutant strains, UV-2 and 5’FDU-1, generated using random mutagenesis through UV light exposure (60 s) and 5’fluorodeoxyuridine (5’FDU-0.25 mM) enhanced the lipid production in marine microalgae, Chlorella vulgaris, with suitable fatty acid profile for biodiesel production, under laboratory conditions. Augmentation in the lipid content in UV-2 (26%) and 5’FDU-1 (23%) mutants was observed in outdoor conditions. Decreased growth rate observed in the mutants under indoor conditions was reversed under outdoor environment compared to wild type. Transcriptome-based gene expression analysis of wild type and mutants explained the variation in growth rate and lipid production. Acetyl-CoA carboxylase and other important fatty acid biosynthesis were significantly upregulated in mutant strains under outdoor conditions, correlating with the increased lipid production in outdoor mutants. Significant upregulation observed in genes related to photosystems in the mutant samples under both indoor and outdoor conditions corroborated with the increased biomass observed in mutant samples. Transcriptome study also provided pointers to the expression levels of key genes involved in carotenoid biosynthesis. Impact of physiological parameters like temperature played vital role in regulating genes related to growth, carotenoid biosynthesis, etc. Variation of gene expression levels of carotenoid biosynthesis genes and transcription factors with respect to indoor and outdoor conditions provided crucial pointers for further downstream studies. The current study evaluating the role of mutation substantiated with transcriptome data could be a precursor towards exploring specific targets for augmenting biomass, lipid leading to enhanced biodiesel production.

基于微藻的生物燃料替代化石燃料，以满足当前的全球能源需求。突变菌株 UV-2 和 5'FDU-1 通过紫外线照射（60 秒）和 5'氟脱氧尿苷（5'FDU-0.25 mM）使用随机诱变产生，增强了海洋微藻小球藻中的脂质生产，在实验室条件下具有适合生物柴油生产的脂肪酸谱。在户外条件下观察到 UV-2 (26%) 和 5'FDU-1 (23%) 突变体中脂质含量的增加。与野生型相比，在室外环境下，突变体在室内条件下观察到的生长速率降低被逆转。野生型和突变体的基于转录组的基因表达分析解释了生长速率和脂质产生的变化。在室外条件下，突变菌株的乙酰辅酶A羧化酶和其他重要的脂肪酸生物合成显着上调，这与室外突变体中脂质产量的增加有关。在室内和室外条件下，突变样本中与光系统相关的基因中观察到的显着上调与突变样本中观察到的生物量增加证实了这一点。转录组研究还为涉及类胡萝卜素生物合成的关键基因的表达水平提供了线索。温度等生理参数的影响在调节与生长、类胡萝卜素生物合成等相关的基因中起着至关重要的作用。类胡萝卜素生物合成基因和转录因子的基因表达水平在室内外条件下的变化为进一步的下游研究提供了重要的指导。目前评估转录组数据证实的突变作用的研究可能是探索增加生物量的特定目标的先驱，