Improvement in Violacein Production by Utilizing Formic Acid to Induce Quorum Sensing in Chromobacterium violaceum

Antioxidants

Chang-Wei Hsieh¹  Kuan-Chen Cheng²  Hsiang-Chun Hsiao²  Hung-Yueh Chen²  Yu-Chen Hou³  Hsien-Yi Hsu⁴  Shin-Ping Lin⁵ 

[1] Department of Food Science and Biotechnology, National Chung Hsing University, 145 Xingda Rd., Taichung 40227, Taiwan;Graduate Institute of Food Science and Technology, National Taiwan University, 1 Roosevelt Rd., Sec. 4, Taipei 10617, Taiwan;Master Program in Food Safety, Taipei Medical University, 250 Wu-Hsing Street, Taipei 11042, Taiwan;School of Energy and Environment, City University of Hong Kong, Kowloon Tong, Hong Kong 518057, China;School of Food Safety, Taipei Medical University, 250 Wu-Hsing Street, Taipei 11042, Taiwan;

关键词: Chromobacterium violaceum;    violacein;    quorum sensing;    formic acid;    microbial pigment;   

DOI  :  10.3390/antiox11050849

来源: DOAJ

【 摘 要 】

Violacein has attracted increasing attention due to its various biological activities, such as antibacterial, antifungal, antioxidative, and antitumor effects. To improve violacein production, formic acid (FA) was added to a culture medium, which resulted in a 20% increase (1.02 g/L) compared to the no-FA-addition group (0.85 g/L). The use of a stirred-tank bioreactor system also improved violacein production (by 0.56 g/L). A quorum-sensing (QS)-related gene (cviI) was induced by FA treatment, which revealed that the mechanism induced by FA utilized regulation of the cviI gene to induce the vio gene cluster for violacein production. To analyze the antioxidative properties of the violacein produced, 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) scavenging tests were conducted, and results reveal that the values of the 50% inhibitory concentration (IC₅₀) of DPPH and ABTS were 0.286 and 0.182 g/L, respectively. Violacein also showed strong inhibitory activity against Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis). In summary, this study found that the addition of formic acid can promote QS of Chromobacterium violaceum, thereby promoting the synthesis of violacein. Subsequently, the promoting effect was also evaluated in a bioreactor system. These findings will be helpful in establishing an economically beneficial production model for violacein in future work.

【 授权许可】

Unknown