背景:蛋白质生产的研究对食品技术的进步具有重要意义,农业,制药,和生物能源。黑曲霉是生产食品级蛋白质的理想微生物细胞工厂,由于其强大的蛋白质分泌能力和优异的安全性。然而,内质网(ER)内蛋白质的广泛氧化折叠引发内质网应激,从而导致蛋白质错误折叠反应。这种压力现象导致活性氧(ROS)的加速生成,从而诱导氧化应激。ROS的积累会对细胞内DNA产生不利影响,蛋白质,和脂质。
结果:在这项研究中,我们通过整合多个模块来增强黑曲霉(SH-1)中ROS的解毒作用,包括NADPH再生工程模块,谷氧还蛋白系统,GSH综合工程模块,和转录因子模块。我们评估了细胞内ROS水平,在胁迫条件下生长,蛋白质生产水平,和细胞内GSH含量。我们的发现揭示Glr1在谷氧还蛋白系统中的过表达在各种参数中表现出显著的功效。具体来说,它将黑曲霉的细胞内ROS水平降低了50%,糖化酶活性提高了243%,总蛋白分泌增加88%。
结论:结果表明,细胞内氧化还原条件的适度调节可以增强整体蛋白质输出。总之,我们提出了一种策略来增加A.niger的蛋白质生产,并提出了一种潜在的方法来优化微生物蛋白质生产系统。
BACKGROUND: Research on protein production holds significant importance in the advancement of food technology, agriculture, pharmaceuticals, and bioenergy. Aspergillus niger stands out as an ideal microbial cell factory for the production of food-grade proteins, owing to its robust protein secretion capacity and excellent safety profile. However, the extensive oxidative folding of proteins within the endoplasmic reticulum (ER) triggers ER stress, consequently leading to protein misfolding reactions. This stressful phenomenon results in the accelerated generation of reactive oxygen species (ROS), thereby inducing oxidative stress. The accumulation of ROS can adversely affect intracellular DNA, proteins, and lipids.
RESULTS: In this study, we enhanced the detoxification of ROS in A. niger (SH-1) by integrating multiple modules, including the NADPH regeneration engineering module, the glutaredoxin system, the GSH synthesis engineering module, and the transcription factor module. We assessed the intracellular ROS levels, growth under stress conditions, protein production levels, and intracellular GSH content. Our findings revealed that the overexpression of Glr1 in the glutaredoxin system exhibited significant efficacy across various parameters. Specifically, it reduced the intracellular ROS levels in A. niger by 50%, boosted glucoamylase enzyme activity by 243%, and increased total protein secretion by 88%.
CONCLUSIONS: The results indicate that moderate modulation of intracellular redox conditions can enhance overall protein output. In conclusion, we present a strategy for augmenting protein production in A. niger and propose a potential approach for optimizing microbial protein production system.