SprI/SprR Quorum Sensing System of Serratia proteamaculans 94

Table 4

Effect of mutation sprI:Gm and introduction of pUCP26-splIR plasmid into the mutant on the properties of cells.

Properties	S. proteamaculans 94	sprI:Gm	sprI:Gm/pUCP26-splIR
AHL production	+	−	+
Extracellular proteolytic activity^a	5.1 ± 2.0	1.2 ± 0.0	4.8 ± 1.5
Chitinolytic activity^b	4.6 ± 1.5	0	4.2 ± 1.0
Lipolytic activity^c	5.4 ± 1.3	4.6 ± 1.5	4.1 ± 2.0
Hemolytic activity^d	2.0 ± 1.0	1.6 ± 0.6	1.9 ± 0.4
Effect of VOCs on R. solani growth^e	7.7 ± 1.5	19.6 ± 3.0	8.4 ± 1.0
Effect of VOCs on H. sativum growth^e	8.6 ± 2.5	21.4 ± 2.0	7.5 ± 1.5
Swimming^f	33.0 ± 2.5	0	24.0 ± 2.0

The results of four independent experiments are expressed as the mean ± standard deviation (SD). Assay of AHL production was performed with the C. violaceum CV026 and A. tumefaciens NT1/pZLR4 biosensors. ^aRadius of the zone of casein hydrolysis, mm. ^bRadius of the zone of hydrolysis of chitin, mm. ^cRadius of the turbid zones around the colonies, mm. ^dRadius of the zone of hemolysis, mm. ^eGrowth of mycelium measured as distance in mm between the block of fungus and the border of its mycelium (action of S. proteamaculans 94 volatile compounds). In the absence of S. proteamaculans 94, the growth of fungal mycelium was 20–24 mm. ^fDiameter of the bacterial growth of the strains around a 2 μl drop of culture grown for 36 h at 30°C.