PHENOTYPIC HETEROGENEITY OF PSEUDOMONAS-CORRUGATA STRAINS FROM SOUTHERN ITALY

Fifty-five strains of Pseudomonas corrugata isolated in southern Italy were characterized phenotypically and compared with 23 strains of dif ferent origins. At least two main cultural types with rough or smooth colonies were observed. Strains with rough colonies produced a diffusi ble pigment in culture. On the basis of their nutritional profiles, Ps . corrugata strains formed a distinct phenon most closely related to f luorescent Pseudomonas spp, isolated from tomato with necrosis-disease d plants. Three major groups of strains were differentiated within the Ps. corrugata phenon on the basis of utilization of 2-ketogluconate, meso-tartrate, hystamine, DL-glycerate and induction of a hypersensiti ve reaction on tobacco, Some Ps. corrugata strains belonging to group 1 and 3 which did not produce pigment in culture produced IAA in a col orimetric test. Variability in the serological reaction of the Italian strain was observed. None of the three antisera utilized reacted with all strains. Some strains isolated from diseased plants from the same greenhouse showed different nutritional profiles and reacted with dif ferent antisera, Fifteen lipopolysaccharide (LPS) patterns were observ ed. Strains were divided into two groups on the basis of their protein profiles. The heterogeneity which had already been observed in a worl d-wide study on Ps. corrugata was confirmed in strains from this restr icted area.