Construction and potential application of bacterial superoxide dismutase expressed in Bacillus subtilis against mycotoxins

• Published in: PloS one Vol. 16; no. 11; p. e0260047
• Main Authors: Dong, Xueqian, Wang, Wei, Jiang, Tianyi, Zhang, Yanmin, Han, Hongyu, Zhang, Yonggang, Yang, Chunyu
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 16.11.2021; Public Library of Science (PLoS)
• Subjects: Analysis; Animals; Antibiotics; Antioxidants; Bacillus subtilis; Bacillus subtilis - genetics; Bacillus subtilis - growth & development; Bacillus subtilis - metabolism; Bacterial Proteins - administration & dosage; Bacterial Proteins - genetics; Bacterial Proteins - pharmacology; Batch Cell Culture Techniques; Biology and Life Sciences; Cloning, Molecular; Culture Media - chemistry; Deoxynivalenol; Drying; Enzyme Stability; Enzymes; Feasibility studies; Feed industry; Feeds; Fermentation; Food; Food industry; Glucose; Industrial production; Industrial research; Isopropyl thiogalactoside; Laboratories; Lactose; Livestock; Livestock industry; Medicine and Health Sciences; Mycotoxins; Mycotoxins - toxicity; Oxidative stress; Oxidative Stress - drug effects; Oxygen; Physical Sciences; Properties; Protein Engineering; Reactive oxygen species; Reactive Oxygen Species - metabolism; Research and Analysis Methods; Superoxide; Superoxide dismutase; Superoxide Dismutase - administration & dosage; Superoxide Dismutase - genetics; Superoxide Dismutase - pharmacology; Thermodynamics; Zebrafish; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0260047

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.