TABLE 2.

Changes in S. thermophilus protein abundance in coculture with L. delbrueckii subsp. bulgaricus between early and late exponential phases

Gene name or locus tag (stu no.)dFunctional categoryDescriptionSpotFold change L vs Eb
2-DEArrayRT-qPCR
ilvCAA metabolismKetol-acid reductoisomerase2322.45.62.1 ± 0.4
239a1.7
ilvBAcetolactate synthase, large subunit924.8NV1.6 ± 0.4
leuB3-Isopropylmalate dehydrogenase2272.0NV1.4 ± 0.2
purCPurine and pyrimidine metabolismPhosphoribosylaminoimidazole- succinocarboxamide3300.50.120.39 ± 0.10
purLPhosphoribosylformylglycinamidine synthase II12NV0.140.03 ± 0.01
13NV
160.48
17a0.46
purHPhosphoribosylaminoimidazole carboxamide formyl transferase1030.240.26
105a0.18
purDPhosphoribosylamine-glycine lyase2050.50.3
204a0.45
purBAdenylosuccinate lyase1780.260.590.22 ± 0.08
purAAdenylosuccinate synthetase179a0.210.40 ± 0.14
201NV
purRPurine operon repressorc30314NV1.90 ± 0.40
guaAGMP synthase1060.37NV
109a0.5
1310.56
pyrCDihydroorotase191a1.75.8
206NV
gorStressGlutathione reductase1720.35NV
gpsAC metabolismGlycerol-3-phosphate dehydrogenase [NAD(P)+]2420.42NV
galUUDP-glucose pyrophosphorylase2640.24NV
exoADNA and RNA metabolism3′ exo DNase III2933.3NV
ileSt-RNA synthetaseIsoleucyl-tRNA synthetase225.3NV
valSValyl-tRNA synthetase286.9NV
pepTPeptidase, proteasePeptidase Tc1560.33NV
rr01Transcriptional regulatorResponse regulator3412.0NV0.26 ± 0.18
folPOtherDyhydropteroate synthase3272.7NV
fhsFormate-tetrahydrofolate ligase1150.380.44
118a0.48
0113Hypothetical protein249a0.130.43
274NV
  • a Most abundant form of the protein.

  • b E, early exponential phase (2 h 30 min); L, late exponential phase (5 h 30 min); L versus E, ratio between the relative mRNA levels at 5 h 30 min and 2 h 30 min; NV, no variation.

  • c Spot of low intensity and missing in one of the three repetitions at the early exponential phase (2 h 30 min).

  • d Boldface type indicates genes with similar variations by 2-DE and transcriptomic analyses. P < 0.05 for 2-DE and microarray assays.