73 ± 0.46 3.31 (2.41-4.56) lamB (R) 0 ± 0.35 1(0.78-1.27) malP (T) Maltodextrin phosphorylase -0.85 ± 0.46 1.80(1.31-2.46) malP (R) 0 ± 0.79 1(0.58-1.72) malQ (T) Amylomaltase -0.96 ± 0.48 1.94(1.39-2.71)
malQ (R) 0 ± 0.55 1(0.68-1.46) malT (T) Transcriptional activator of maltose-regulon genes -0.75 ± 0.32 1.68(1.34-2.09) malT (R) 0 ± 0.79 1(0.58-1.72) * Fold change is the fold increase or decrease in the level of expression of a gene in the wild type exposed to BALF (target sample, abbreviated as T) relative to the level of expression of the gene in the wild type exposed to BHI (calibrator or reference sample, abbreviated as R), as measured by real-time PCR. Values in the parentheses represent the range in the fold change. Figure 1 Silver-stained gel comparing
A. pleuropneumoniae RT-PCR DD products in BHI broth (1) and BALF (2). The arrow points to the band representing a differentially see more expressed gene, which based on cloning and sequencing (see Methods), appeared to be lamB. Growth curves of the malT and lamB mutants The malT mutant grew slower than the wild-type organism in BHI. The growth pattern of the lamB mutant was, however, similar to https://www.selleckchem.com/products/bmn-673.html that of the wild-type organism (Figure 2). Figure 2 Growth curves of the wild type strain and lamB and malT mutants in BHI broth. Effect of acarbose on the growth of the isogenic malT and lamB mutants of A. pleuropneumoniae
CM5 To assess the effect of the malT knockout mutationon the functioning of the maltose regulon, the parent strain and the malT mutant were grown in acarbose-containing BHI in the presence or absence of maltose. Acarbose is a competitive inhibitor of maltose transport . Because of the fastidious nutritional requirements of A. pleuropneumoniae, this experiment was performed in BHI instead of a chemically Bcl-w defined medium. After 16 h of incubation in acarbose-containing BHI that was supplemented with maltose, the wild-type organism reached a significantly lower OD600 (P < 0.05) than did the malT mutant (Figure 3). In acarbose-containing BHI that was not supplemented with maltose, there was again, a significant difference in the growth of the two strains. The number of wild type and malT mutant cells was lower in acarbose-containing BHI than in the BHI containing both maltose and acarbose; however, this difference was not significant (Figure 3). The lamB mutant showed a trend similar to that of the malT mutant grown in the acarbose-containing medium, but the number of lamB mutant cells was lower than that of the malT mutant; however, this difference was not significant. Figure 3 Overnight growth of the wild type strain and the lamB and malT mutants in acarbose or maltose. The bars with same letters on the top do not differ significantly (P < 0.