Haisheng Wang, Fengzhong Wang, Xiaofei Zhu
Aug 15, 2012
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0
Influential Citations
47
Citations
Journal
Biochemical Engineering Journal
Abstract
Abstract Violacein is a natural bisindole pigment produced by bacteria, which has attracted much attention recently for its antibacterial, antiviral, antitumor, and antioxidant activities. To better understand the bioactive properties of violacein derivatives, deoxyviolacein and oxyviolacein were biosynthesized by genetically engineered strains of Citrobacter freundii(pComvio) and C. freundii(pComvioΔd), respectively, using l -tryptophan or 5-OH- l -tryptophan as the precursor, respectively. The structure of oxyviolacein was confirmed based on HPLC–MS and NMR analysis. Deoxyviolacein and oxyviolacein were evaluated for their effectiveness against bacteria and phytopathogenic fungi. The two pigments exhibited strong activities against all Gram-positive bacteria tested except Streptococcus sp. Oxyviolacein showed a surprisingly high activity against Phytophthora capsici, a devastating pathogen of vegetable crops, and also showed strong antifungal activity against Fusarium oxysporum, Botrytis cinerea, and Verticillium dahliae at 0.5 mg mL−1. Deoxyviolacein showed strong antifungal activity against Rhizoctonia solani at concentrations exceeding 2 mg mL−1. The presence of a hydroxyl group appeared to be essential for their bioactivities. These findings provide important information for the further exploitation of violacein and its derivatives as fungicides.