Characteristics of Growth and Metabolism of Thermoascus aurantiacus QH-1 Derived Hongxinqu

To explore the growth metabolic characteristics of Thermoascus aurantiacus, the optimal growth conditions, ethanol tolerance, growth curve, saccharifying power and liquefaction power of Thermoascus aurantiacus QH-1 were analyzed. The results showed that Thermoascus aurantiacus QH-1 grew rapidly and had pigment in PDA, MEA and SDA mediums with rich in nutrients, and colonies growing on synthetic medium and G25N medium grew slowly and almost no pigment. The optimal growth conditions of T.aurantiacus QH-1 strain was as follows: Temperature 45 ℃, pH4.0, inoculum concentration 3%, liquied loading volume 160 mL. The lowest and highest growth temperatures of Th. aurantiacus QH-1 were 26 and 60 ℃, respectively. Among the raw materials for brewing Daqu, sorghum rice was the best for its growth, and the concentration of 6% ethanol had no effect on the grwoth of T.aurantiacus QH-1. T.aurantiacus QH-1 grew slowly with lower saccharifying power in the early stage, and the growth rate accelerated with the higher saccharifying power at 6~8 days in solid state medium of barley and pea. The growth curve of T.aurantiacus QH-1 was similar to its change curve of saccharifying power. However, its liquefying power was detected on day 10. The results provided necessary information for the further development and utilization of T.aurantiacus QH-1.