Temperature-dependent expression of elastase in Aspergillus species

We examined elastase production by Aspergillus species at different temperatures. All 20 isolates failed to grow at 22°C, whereas 18 grew and 16 produced elastase at 37°C. Maximal production of elastase was at 33°C (compared with 30°C, 36°C and 42°C) in 11 Aspergillus fumigatus, three Aspergillus flavus and eight Aspergillus terreus isolates. All five Aspergillus niger isolates grew at 33°C but failed to produce an elastase zone. The optimal temperature for elastase expression was 33°C.