Alternative sigma factor σH activates competence gene expression in Lactobacillus sakei

BMC Microbiology

Table 1 Relative expression ratio^$ of sigH and comEA with or without overexpression of sigH

Sample	sigH(wt)* i		sigH(hy)* ni		sigH(hy)* i
Calibrator	sigH(wt)* ni		sigH(wt)* ni		sigH(wt)* i
Measured effect	control of the inducer effect in wt strain		presence of the additional copy of sigH		cumulative effect of induced additional copy
Time (h)	1	4	1	4	1	4
sigH	1	1	7	24	40	200
comEA	1	1	2	3	370	80

^$ Expressed as fold change of transcripts amounts of each gene in each given sample relative to the indicated calibrator and normalized with ldh. Results are the mean of two independent experiments. The level of ldh transcripts was stable, irrespective of the copy number or induction status of sigH (e.g. mean fold change across all induced samples relative to non induced samples: 0.9 ± 0.2). Note that sigH is present at one (chromosomal) copy in sigH(wt)* and at two copies (one additional copper-controlled copy on a plasmid) in sigH(hy)*; the transcription of both is measured simultaneously. ni and i refer to 'not induced' and 'induced', respectively.

ISSN: 1471-2180