State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, China.
Shandong Provincial Key Laboratory of Food & Fermentation Engingeering, Shandong Food Ferment Industry Research & Design Institute, QiLu University of Technology (Shandong Academy of Sciences), Jinan, China.
PLoS One. 2021 Nov 16;16(11):e0260047. doi: 10.1371/journal.pone.0260047. eCollection 2021.
Oxidative stress, which could be evoked by numerous inducements including mycotoxins like deoxynivalenol (DON), cause severe damages to organisms. Antioxidants are promising protectants against oxidative stress that could be applied in pharmaceutical, cosmetic, and food and feed industries. In this study, a thermostable and acidophilic superoxide dismutase (AaSOD) was used to develop an antioxidant product that can potentially protect organisms from oxidative stress related damages. The enzyme was successfully expressed as an extracelluar protein in Bacillus subtilis with a high yield. To obtain a feasible protocol for industrial production of AaSOD, the fermentation mediums that are commonly used for culturing B. subtilis were screened, the feasibility of expressing AaSOD without antibiotic as selection pressure was confirmed, and the effect of using lactose as an inducer instead of isopropyl-β-d-thiogalactoside (IPTG) was investigated. Batch fermentation was conducted to validate the optimized conditions for AaSOD production, and 6530 U mL-1 of SOD activity was obtained in the fermentation broth. The dry powder product of AaSOD with an activity of 22202 U g-1 was prepared by spray-drying and was administrated on zebrafish to test its function as a protectant against DON, and thus gained a significant redress of the reactive oxygen species (ROS) accumulation induced by DON. Taken together, this study provides a feasible protocol to prepare the AaSOD-based antioxidant product that is potentially applied in livestock industry.
氧化应激是由多种诱导物引起的，包括真菌毒素如脱氧雪腐镰刀菌烯醇 (DON)，会对生物体造成严重损害。抗氧化剂是一种有前途的抗氧化物，可以应用于制药、化妆品、食品和饲料行业。在本研究中，一种耐热嗜酸超氧化物歧化酶 (AaSOD) 被用于开发一种抗氧化产品，该产品可能有助于保护生物体免受与氧化应激相关的损害。该酶在枯草芽孢杆菌中成功地作为胞外蛋白表达，产量很高。为了获得可行的工业生产 AaSOD 的方案，筛选了常用于培养枯草芽孢杆菌的发酵培养基，证实了在没有抗生素作为选择压力的情况下表达 AaSOD 的可行性，并研究了使用乳糖作为诱导剂而不是异丙基-β-d-硫代半乳糖苷 (IPTG) 的效果。进行分批发酵以验证 AaSOD 生产的优化条件，在发酵液中获得了 6530 U mL-1 的 SOD 活性。通过喷雾干燥制备了 AaSOD 的干粉产品，其活性为 22202 U g-1，并将其施用于斑马鱼以测试其作为 DON 保护剂的功能，从而显著减轻 DON 诱导的活性氧 (ROS) 积累。总之，本研究提供了一种可行的方案来制备基于 AaSOD 的抗氧化产品，该产品可能应用于畜牧业。
