To enhance specific or total sophorolipids (SLs) production by Starmerella bombicola for specific application, mutant library consisting of 106 mutants from 7 batches was constructed via atmospheric and room-temperature plasma (ARTP). When compared to the wild strain, 11, 36 and 12 mutants performed increases over 30% in lactonic, acidic or total SLs production. Genetic stability investigation showed that 8, 7, and 4 mutants could maintain the improved SLs production capacity. Mutants of A6-9 and A2-8 were selected out for enhanced specific SLs and total SLs production in fed-batch cultivation in flask. Without optimization, A6-9 obtained the highest reported lactonic SLs production of 51.95 g/l and A2-8 performed comparable acidic and total SLs production of 68.75 g/l and 100.33 g/l with all the reported stains. The structural composition of the obtained SLs was analyzed by HPLC and LC/MS, and the results confirmed the enhancement of SLs and certain SL components. These mutants would be important in industrial applications because the production and purification costs of SLs could be greatly reduced. Besides, the acquisition of these mutants also provided materials for the investigation of regulation mechanism of SLs biosynthesis for further genetic engineering of S. bombicola. Furthermore, critical micelle concentration (CMC), minimum surface tension (STmin) and hydrophilic-lipophilic balance (HLB) of the SLs obtained from the wild and mutant strains were also examined and compared. These results demonstrated the feasibility of obtaining SLs with different properties from different strains and the high efficiency of mutation breeding of S. bombicola by ARTP.

中文翻译：

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通过大气和室温血浆（ARTP）进行Starmerella bombicola的突变育种，以改善特定或全部槐糖脂的生产。

为了提高Starmerella bombicola的特定或全部槐糖脂（SLs）的生产量，以用于特定用途，通过大气和室温血浆（ARTP）构建了由7个批次的106个突变体组成的突变体文库。与野生株相比，内酯，酸性或总SL产生的11、36和12个突变体的产量增加了30％以上。遗传稳定性研究表明，8，7和4个突变体可以维持提高的SLs生产能力。选择A6-9和A2-8的突变体以增强烧瓶中分批补料培养中的特定SL和总SL的产生。如果不进行优化，A6-9的内酯SLs产量最高，为51.95 g / l，A2-8的酸性SLs产量为68.75 g / l，总SLs的产量为100.33 g / l。通过HPLC和LC / MS分析获得的SL的结构组成，结果证实了SL和某些SL组分的增强。这些突变体在工业应用中将是重要的，因为可以大大降低SL的生产和纯化成本。此外，这些突变体的获得还为进一步研究SLs的生物合成调控机制提供了材料。此外，还检查并比较了从野生株和突变株获得的SL的临界胶束浓度（CMC），最小表面张力（STmin）和亲水亲脂平衡（HLB）。这些结果证明了从不同菌株获得具有不同特性的SL的可行性以及S的突变育种的高效率。