TABLE 3 .

Comparison of PalgD induction in mutants of the σ²² stimulon when in the planktonic and sessile states of growth

Phenotype	Strain/ mutation	Activity of untreated planktonic PalgD-lacZ:activity of that treated with d-cycloserinea	Sessile PalgD-cat treated with d-cycloserineb	Putative role of gene product
Wild type	PAO1	1:100	Ring
Alterations in stressed PalgD expression	PA3459	1:67	Weaker ring	Osmoprotectant
	PA5424	1:52	Weaker ring	Membrane protein
	PA1243	1:153	Ring	Sensor/regulator
	PA5107	1:134	Ring	Lipocalin
Growth-independent alterations in unstressed PalgD expression	PA0062	6:131 (Ts)	Lawn	Lipoprotein
	PA1324	1.7:151 (Ts)	Lawn	Polysaccharide binding
Planktonic growth-specific alterations in unstressed PalgD expression	PA5178	7:215	Ring	LysM, BON domains
Sessile growth-specific alterations in unstressed PalgD expression	PA0567	1:100	Lawn	UPF0057 domain
	PA3040	1:100	Lawn	DUF883 family
	PA2717	1:142	Lawn	Chloroperoxidase
	PA0920	1:55	Lawn	A-PG synthasec

^a PalgD-lacZ Miller units of β-galactosidase in PAO1 strains were 13 (±7) if untreated and 1,161 (±231) if treated with d-cycloserine. To be significant in the fold change, the ratio needed to be <0.5 or >1.5 for untreated cultures and <80 or >120 for treated cultures. When maximum activity was normalized to 100%, the untreated/treated ratio of PalgD-lacZ expression in PAO1 was typically 1:100. Ts indicates a temperature-sensitive growth defect at 45°C.

^b PalgD-cat activity in PAO1 strains was estimated on L agar plates containing chloramphenicol to prevent growth unless the cat fusion was activated by d-cycloserine placed in the center of the plate, which resulted in a ring of growth. In some mutants, a weaker ring of growth was observed. A lawn of growth indicated constitutive PalgD-lacZ expression under such sessile conditions.

^c A-PG, aminoacyl-phosphatidyl glycerol.