The chrome azurol S ( CAS ) assay was used to detect the siderophore production and its affinity to ferric ion. The strain was identified by using morphological, biochemical and physiological characteristics, 16S rRNA sequence homology, phylogenetics and specific species molecular analysis.
Forty strains of Flavobacterium psychrophilum were tested for the production of siderophores using the universal Chrome Azurol S ( CAS ) assay . The majority of the strains (85%) were CAS positive (CAS+) and some (15%) were CAS negative ( CAS -).
27/08/2010 ÿú The chrome azurol S ( CAS ) assay , a common diagnostic test for siderophore production , was used to determine if an iron-chelating metabolite was produced in liquid culture medium. This determination was carried out on culture supernatant (typically 50-ml cultures) that was neutralized to pH 6.5 by using 0.2 M HCl.
assayed by the universal chrome azurol S ( CAS ) assay . Briefly, 1 mL of culture filtrate was added to 2 mL of CAS solution and the absorbance at 630 nm was measured after 30 min incubation at room temperature. The concentration of the siderophore is expressedas siderophore units. One siderophore unit= (Ae-As/Ad x 100, where Ac represents the, onto Chrome - azurol S ( CAS ) medium (2). Plates were incubated at 28øC for 2 d. The siderophore-solubilizing activity (formation of an orange or yellow halozone around colonies) of each isolate was evaluated by measuring the size of the orange or yellow zone.
was also carried out with the chrome azurol S ( CAS ) reagent in a spectrophotometric assay (14). The total data collected from the isolates are shown in Table 1. King A and King B solid media were streaked from Luria-Bertani plate cultures of the isolates and incubated overnight at 37øC. The CAS assay was, 22/02/2017 ÿú Please read this paper Use of chrome azurol S reagents to evaluate siderophore production by rhizosphere bacteria ... To prepare CAS solution for siderophores assay.
Total siderophores were quantified using the Chrome Azurol S ( CAS ) assay . The CAS solution was prepared as previously described (Alexander and Zuberer, 1991). In a 96-well plate , equal volumes of CAS solution and supernatant were mixed together and incubated for 30, An aliquot of the filtrate was subjected to the modified Schwyn and Neilands chrome azurol S ( CAS ) assay for detection and determination of the iron-complexing ligands secreted by C. aciculare ...;"