Table 2.

COMSTAT Analysis of Biofilms Formed by Streptococcus gordonii With or Without GbpA^*

Strain	Biomass	%Coverage at Substratum	Average Thickness	Roughness Coefficient#	Surface/Volume
CH1	6.7 +/- 0.4	56.4 +/- 2.6	8.8 +/- 0.6	0.75 +/- 0.03	2.2 +/- 0.1
CH1(gbpA)	8.7 +/- 0.9	67.3 +/- 5.8	10.5 +/- 1.0	0.64 +/- 0.09	1.8 +/- 0.1
Student t-test result	p<0.05	NS	NS	NS	p<0.05
CH107	11.1 +/- 0.9	86.9 +/- 2.0	11.5 +/- 0.9	0.40 +/- 0.02	1.3 +/- 0.1
CH107(gbpA)	13.7 +/- 0.9	85.6 +/- 1.9	14.3 +/- 0.9	0.49 +/- 0.03	1.0 +/- 0.1
Student t-test result	p=0.05	NS	p<0.05	p<0.05	NS
DS512	1.2 +/- 0.2	20.7 +/- 1.8	1.5 +/- 0.4	1.31 +/- 0.06	3.3 +/- 0.3
DS512(gbpA)	1.1 +/- 0.4	21.9 +/- 5.8	1.1 +/- 0.4	1.43 +/- 0.13	3.3 +/- 0.2
Student t-test result	NS	NS	NS	NS	NS

^*The values in each column represent the mean plus or minus the standard error of the mean.

^#The roughness coefficient is a measure of the variation in biofilm thickness (Heydorn et al., 2000).

NS = Not significant