Figure 5
Role of Acthi in thiamine biosynthesis. (A) Growth of the Acthi mutants on MMC medium. Acthi(−), WT and Acthi(+) were inoculated on MMC medium in the presence or absence of thiamine. Plates were incubated at 28°C for 7 days. The Acthi silencing mutant grew poorly; however, rapid growth was recovered in thiamine-supplemented medium. (B) Detection of thiamine content in the Acthi mutants. The mycelium of Acthi mutants was collected on fermentation days 4 and 7. Samples were treated as described in the Methods and then detected by a microplate reader. Data were presented as the means ± SD with n = 3 independent assays per data point. Significant differences in the thiamine contents in Acthi(−) and Acthi(+) compared with WT are indicated as “*”; p value confidence levels: “**” < 0.01 and “***” < 0.001. The thiamine content in Acthi(+) reached approximately 38 μg g−1 by fermentation day 7, which was significantly higher than in the WT strain. In contrast, the thiamine content was decreased in the Acthi(−) strain.