Affiliation:
1. School of Food Science and Pharmaceutical Engineering Nanjing Normal University Nanjing Jiangsu Province China
2. State Key Laboratory of Materials‐Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering Nanjing Tech University Nanjing Jiangsu Province China
3. School of Chemical Engineering Yangzhou Polytechnic Institute Yangzhou Jiangsu Province China
Abstract
AbstractTo better understand the characteristic properties of violacein biosynthesized by engineered Escherichia coli VioABCDE‐SD, a convenient and simplified method was designed to extract violacein and its stability, antimicrobial activity, and antioxidant capacity were analyzed. Different from the traditional extraction methods, our new method is easier and less time consuming and can directly obtain violacein dry powder product with a higher extraction rate. Low temperature, dark condition, neutral pH, reducing agents, Ba2+, Mn2+, Ni2+, Co2+, and some food additives of sucrose, xylose, and glucose were conducive to maintaining its stability. The violacein also exhibited surprisingly high bacteriostatic action against Gram‐positive Bacillus subtilis, Deinococcus radiodurans R1, and Staphylococcus aureus and Gram‐negative Pseudomonas aeruginosa, but no effect on E. coli. The violacein of VioABCDE‐SD exhibited strong antioxidant activity, with the scavenging rate of 1,1‐diphenyl‐2‐picrylhydrazyl free radicals reaching 60.33%, the scavenging efficiency of hydroxyl radical scavenging reaching 56.34%, and the total antioxidant capacity reaching 0.63 U/mL. Violacein from VioABCDE‐SD can be synthesized directionally with better stability, antibacterial, and antioxidant properties compared with that from the original strain Janthinobacterium sp. B9‐8. Therefore, our study indicated that violacein from engineered E. coli VioABCDE‐SD was a kind of new antibiotic with potential biological activities, which may have potential utility in multiple areas such as pharmacological, cosmetics, and healthy food industries.
Funder
Natural Science Foundation of Jiangsu Province
National Natural Science Foundation of China
Subject
Process Chemistry and Technology,Drug Discovery,Applied Microbiology and Biotechnology,Biomedical Engineering,Molecular Medicine,General Medicine,Bioengineering,Biotechnology