Studies on the Synthesis of Alpha-Amylase and Free Amino Acids by Mutants of Aspergillus Oryzae

SUMMARY

The effectiveness of ultra-violet rays and α radiation from polonium²¹⁰ in causing mutations affecting the synthesis of α-amylase in 24 industrially important monoconidial isolates of Aspergillus spp. was studied. Mutants were obtained from Aspergillus oryzae (Ahlburg) Cohn, isolate 6A, whose cultures differed from 6A in growth, sporulation and α-amylase activity, α-amylase production by mutants 6A20M1 and 6A20M8 was quantitatively determined by amylograph and dextrinization methods. Isolate 6A20M8 produced more than twice as much α-amylase as the parent isolate 6A. Chromatographic analyses of culture filtrates of the various mutants and parent isolates indicated that mutations which affected amylase synthesis also influenced the metabolism of free amino acids by these fungi.

Grateful acknowledgments are made to Robert J. Klug, George C. Papavizas, and John F. Tuite of the Department of Plant Pathology and Botany, and to Neville Prentice of the Department of Agricultural Biochemistry for their assistance in certain phases of this research.