TABLE 2.

Stress responses are activated in P. aeruginosa biofilms relative to those in exponential-phase planktonic cultures^a

Activityb	P value for association with differential gene expression in biofilms
	Upregulation	Downregulation
Stationary phase	10−15	1.00
Zn limitation	10−15	1.00
Oxygen downshift	10−14	0.16
Oxygen limitation	10−13	0.98
HSL quorum sensing	10−10	0.42
Denitrification	10−6	1.00
Phenazine biosynthesis	10−4	1.00
Virulence factors	10−3	1.00
Osmotic stress	10−3	1.00
Ammonia release	0.05	10−6

^aBased on gene set enrichment analysis (2-fold change).

^bHSL, homoserine lactone.