TABLE 1.

Characteristics of Vp (primary form) and Vsm (small-colony variant) of P. luminescens MD

Characteristic	Vp	Vsm
Gram stain	Negative	Negative
Mean cell size (μm) (range)	5.0 by 1.3 (3.0 by 1.0 to 8.0 by 1.8)	2.1 by 0.9 (1.5 by 0.8 to 3.0 by 1.0)
Proteinaceous granules	Yes	No
Colony color on TSA	Yellowish	Light grey
Colony size and form on TSAD	Large; dark-green center with radial stripes	Small; light green and homogeneous
Colony adhesion	Strong	None
Dye absorption
Bromothymol blue on TSA	Strong	Weak
Neutral red on TSA	Strong	Weak
Neutral red on MacConkey agar	Strong	Weak
Pigment diffusible on TSA	Brown	None
Catalase	Yes	Yes (weak)
Antibiotic production	Yes	No
Luminescence	Strong	Weak