Study on extraction and characterization of new antibiotics violacein from engineered Escherichia coli VioABCDE ‐SD

AbstractTo better understand the characteristic properties of violacein biosynthesized by engineeredEscherichia 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-positiveBacillus subtilis,Deinococcus radiodurans R1, andStaphylococcus aureus and Gram-negativePseudomonas  aeruginosa, but no effect onE. 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 strainJanthinobacterium sp. B9-8. Therefore, our study indicated that violacein from engineeredE. coli VioABCDE-SD was a kind of new antibiotic with potenti...
Source: Biotechnology and Applied Biochemistry - Category: Biochemistry Authors: Tags: ORIGINAL ARTICLE Source Type: research