Antifungal activity of violacein purified from a novel strain of Chromobacterium sp. NIIST (MTCC 5522)

Abstract

A novel strain of Chromobacterium sp. NIIST (MTCC 5522) producing high level of purple blue bioactive compound violacein was isolated from clay mine acidic sediment. During 24 h aerobic incubation in modified Luria Bertani medium, around 0.6 g crude violacein was produced per gram of dry weight biomass. An inexpensive method for preparing crystalline, pure violacein from crude pigment was developed (12.8 mg violacein/L) and the pure compound was characterized by different spectrometric methods. The violacein prepared was found effective against a number of plant and human pathogenic fungi and yeast species such as Cryptococcus gastricus, Trichophyton rubrum, Fusarium oxysporum, Rhizoctonia solani, Aspergillus flavus, Penicillium expansum, and Candida albicans. The best activity was recorded against Trichophyton rubrum (2 -g/ml), a human pathogen responsible for causing athlete-s foot infection. This is the first report of antifungal activity of purified violacein against pathogenic fungi and yeast.

Interplay between two quorum sensing‐regulated pathways, violacein biosynthesis and VacJ/Yrb, dictates outer membrane vesicle biogenesis in Chromobacterium violaceum

“…Violacein purification and quantification. Violacein was purified as previously described (Sasidharan et al, 2015) with some modifications. Chromobacterium violaceum was grown in 1 l LB (24 h; 37 C; 250 rpm), cultures were centrifuged (1 h; 10 000g; 4 C), and OMVs were isolated from the supernatant as described above.…”

Investigating the potential use of an Antarctic variant of Janthinobacterium lividum for tackling antimicrobial resistance in a One Health approach

“…have shown that nanoparticles loaded with violacein were two to five times more effective than violacein alone against MRSA, justifying its possible real application in medical industries. Violacein also has an anti-proliferative activity against cancer cells lines 62 , anticancer activity against human breast cancer cells in a time and dose-dependent manner 63 and antifungal activity 64 .…”

Optoregulated Drug Release from an Engineered Living Hydrogel

“…10 Among these, the L-tryptophan-derived bisindoles, i.e. deoxyviolacein and the structurally analogous violacein, are attractive due to their antibacterial, 36,37 antifungal, 38 and anti-tumoral properties 37,39 and the possibility to produce them at gram scales with E. coli. 34,35 Numerous available genetic modules allow it to respond E coli.…”