Moradi Hamideh, Zare Davood, Azin Mehrdad, Moghimi Hamid
Department of Biotechnology, Iranian Research Organization for Science and Technology, Tehran, Iran.
Department of Microbiology, School of Biology, College of Science, University of Tehran, Tehran, Iran.
Sci Rep. 2025 Aug 6;15(1):28748. doi: 10.1038/s41598-025-13082-4.
Blakeslea trispora is an important microbial producer of natural β-carotene, a valuable compound with significant nutritional and industrial applications. In the present study, an adaptive laboratory evolution (ALE) approach was applied to increase β-carotene production by exposing wild-type and UV-mutant B. trispora strains to increasing concentrations of the biosynthetic stressor acetoacetanilide. Over 95 serial transfers spanning 16 months, the adapted strain A78 showed a 45% increase in β-carotene yield (54 ± 1.95 mg/L) compared to the wild type (21.6 ± 2.11 mg/L), without a major compromise in biomass accumulation. Quantitative RT-PCR analysis revealed the upregulation of key carotenogenic genes, particularly hmgR, carRA, and SR5AL, in the adapted strains. Additionally, morphological changes, unsaturated fatty acid content, and altered antioxidant enzyme activities were investigated. The results show that chemical stress in the ALE strategy is effective in increasing metabolite production and stress tolerance of filamentous fungi and can pave the way for improving industrial strains.
三孢布拉氏霉菌是天然β-胡萝卜素的重要微生物生产者，β-胡萝卜素是一种具有重要营养和工业应用价值的化合物。在本研究中，采用适应性实验室进化（ALE）方法，通过将野生型和紫外线突变型三孢布拉氏霉菌株暴露于浓度不断增加的生物合成应激源乙酰乙酰苯胺中来提高β-胡萝卜素的产量。在跨越16个月的95次连续传代过程中，适应菌株A78的β-胡萝卜素产量（54±1.95mg/L）相比野生型（21.6±2.11mg/L）提高了45%，且生物量积累没有受到重大影响。定量逆转录聚合酶链反应（RT-PCR）分析显示，适应菌株中关键类胡萝卜素生成基因，特别是hmgR、carRA和SR5AL的表达上调。此外，还研究了形态变化、不饱和脂肪酸含量和抗氧化酶活性的改变。结果表明，ALE策略中的化学应激在提高丝状真菌的代谢产物产量和应激耐受性方面是有效的，并可为改良工业菌株铺平道路。
