ISSN: 2578-4994
Authors: Kadam NA*, Raghuwanshi KS and Borkar SG
In the present study, we evaluated the effect of aromatic oil’s vapour phase (aroma) on the melanin production in plant pathogenic bacteria Xanthomonas campestris pv. vesicatoria (Xcv), the causal agent of bacterial blight of tomato. Species of the genus Xanthomonas typically produce yellow xanthomonadin pigment, but here in the presence of aromatic oil’s vapour phase the bacterium produced a melanin-like pigment. Among the 10 commercially available synthetic aromatic oils tested, Xcv produced yellow colonies with dark brown extracellular melanin-like pigment in Nutrient Agar media, in the presence of vapour phase of dhavana (Artemisia pallens), henna (Lawsonia inermis), kasturi (Musk of deer), firdous (Combination of Jasminum officinale, Cinnamomum verum, and Nelumbo nucifera), and rose (Rosa damascena) aromatic oils. Firdous and rose aromatic oil treatments were further used to produce pigment in Nutrient broth, which yielded 4.61 ± 0.07 and 5.13 ± 0.08 mg/ ml pigment, respectively. After extraction and purification of the pigment, its characterization was carried out by employing the analytical techniques like Ultraviolet-Visible (UV-Vis) spectrophotometer and Fourier Transmission Infra-red (FTIR) Spectrometer, and the pigment was confirmed as melanin. Till date, melanin pigment has been reported in algae, bacteria, fungus, lichen, and mushroom, but it has not been reported in plant pathogenic bacteria particularly Xcv and therefore this is the first report. Also, the report of aromatic oil’s vapour phase mediated melanin production in bacteria is novel and can be further explored to identify high melanin yielding microbe, owing to the increasing demand for melanin in the market and its versatile applications.
Keywords: Xanthomonas campestris pv. vesicatoria (Xcv); Melanin Pigment; Aromatic Oils Vapour Phase
