A spectrophotometric method to determine the siderophore production by strains of fluorescent Pseudomonas in the presence of copper and iron

摘要

A simple procedure to determine levels of siderophore production by strains of Pseudomonas, particularly the Avm strain is described. Bacterial cells were incubated for 24 h in iron-rich (RM) and iron-limiting conditions (RM-Fe) with and without 6 and 60 mu M of CuSO4. Cells grown under iron-limiting conditions developed a green color even in the presence of Cu. The spent media supernatants from the Avrn cells grown in RM-Fe medium showed a maximum peak of absorbance at 400 nm, which suggest that this strain produced a single type of sideropbore. The presence of 60 mu M of CuSO4 in the cultures did not interfere with the detection of siderophores in the spent media. Clear supernatants obtained from cultures of 10 fluorescent Pseudonionas were diluted 1 to 10 in deionized water and the absorption at 400 nm was determined. The results demonstrated the clear discriminating capacity of this highly practical procedure to categorize a great number of fluorescent Pseudomonas strains by the range of siderophore production. (c) 2005 Elsevier B.V All rights reserved.