Abstract: A method for producing L-glutamic acid by fermentation which comprises culturing aerobically in a culture medium a mutant of the genus of Brevibacterium or Corynebaterium which is resistant to Decoyinine or Tubercidin and capable of producing L-glutamic acid, and recovering the L-glutamic acid accumulated in the culture medium.

Abstract: A method is provided for producing a peptidase capable of substantially completely hydrolyzing protein into its constituent amino acids which comprises culturing a strain of filamentous fungus, belonging to one of the species Aspergillus oryzae and Aspergillus soyae and characterized in that said strain is capable of producing said peptidase, in a nutrient culture medium containing at least one substrate selected from the group consisting of a fatty acid having 14, 16, 18 or 20 carbon atoms and a derivative of said fatty acid, and recovering said peptidase from said culture medium. It is particularly effective to use a combination of a sugar ester of a fatty acid and a vegetable oil as substrates in a liquid culture medium.