Psychrotrophic violacein-producing bacteria isolated from Lake Winnipeg, Canada

Discovery of Siderophore and Metallophore Production in the Aerobic Anoxygenic Phototrophs

“…Furthermore, several AAP had been recovered from the freshwaters of Lake Winnipeg whilst the habitat was under study [ 29 , 30 ]. Specifically, in the spring of 2017, strain AJ72 was collected at Grand Beach from littoral water, AM19, AM27 and AM91 were from littoral sediment of Victoria Beach.…”

“…AAP isolated from the meromictic Blue Lake in British Columbia, Canada, were cultured using a Blue Lake medium (BLM) containing (g/L): MgSO 4 , 0.5; NH 4 Cl, 0.3; KH 2 PO 4 , 0.3; KCl, 0.3; CaCl 2 , 0.05; NaCl, 12.0; NaHCO 3 , 0.5; Na-acetate, 1.0; malic acid, 1.0; yeast extract, 1.0; bactopeptone, 0.5; with vitamins and trace elements solutions, 2.0 mL each; autoclaved at pH 5.9 and then adjusted after autoclaving to pH 7.5 with 0.5 N NaOH. Furthermore, several AAP had been recovered from the freshwaters of Lake Winnipeg whilst the habitat was under study [29,30]. Specifically, in the spring of 2017, strain AJ72 was collected at Grand Beach from littoral water, AM19, AM27 and AM91 were from littoral sediment of Victoria Beach.…”

Natural Pigments of Bacterial Origin and Their Possible Biomedical Applications

“…Its molecular mass is 343,341 g/mol and it is insoluble in water, soluble in alcohols such as methanol, ethanol, and acetone, soluble in DMSO, methanol, and ethyl acetate, and slightly soluble in dioxane and acetone [ 24 , 25 ]. All the species known to be able to produce violaceins are heterotrophic, have predominantly been discovered in aquatic ecosystems and many representatives of these species have been isolated from cold environments, such as Arctic ice, freshwater, and marine habitats [ 26 ]. The initial activity reports on this pigment date from 1942, indicating that raw extracts of a purple pigment produced by the strain Chromobacterium violaceum mixed with bacterial suspensions prevented the soil amoebas from ingesting these bacteria, which would otherwise be phagocytized [ 27 ].…”

“…However, this pigment has also been described in the genera Janthinobacterium , Alteromonas , Collimonas , Duganella , Pseudoalteromonas, and Iodobacter [ 23 , 25 , 26 , 28 ]. The biosynthesis and biological properties of this pigment have been studied extensively, and its production in nature, exclusively intracellular, may be related to a defense mechanism against fast-growing organisms by detaching vesicles loaded with this molecule, which can destroy nearby membranes [ 26 ]. This was verified recently when this compound was related to a lethal effect in Batrachochytrium dendrobatidis , an amphibian-specific fungus [ 28 ].…”

“…In the last five years, five new strains have been identified as producers of this pigment; these belong to the genera Pseudoalteromonas , Iodobacter , Janthinobacterium, and Massilia. This last one has never before been described as a violacein producer [ 23 , 26 , 28 ]. On the other hand, the anticancer properties of the purple pigment have been evaluated, attributing it to the ability to induce extrinsic and intrinsic mechanisms of apoptosis in MCF-7 breast cancer cells [ 29 ].…”