Abstract: A process for making D-aminoacylse includes adding 1% N-acetyl-DL-amino acid preferably N-acetyl-DL-methionine and N-acetyl-DL-leucine in a culturing medium incubated with bacteria selected from the strain of Alcaligenes faecalis for culturing the bacteria and for inductively promoting an enzyme reaction to produce the D-aminoacylase which is able to hydrolyze D-amino acids and unable to hydrolyze L-amino acids.

Abstract: A student's multi-function protractor for conveniently drawing different geometric figures including a transparent middle plate which fits on the retainment space between an upper base and a lower base. The middle plate is rotatable in the retainment space. The circumferential edge with the middle plate of the upper base has a 360 degree scale. In addition, the middle plate has a plurality of parallel grooves which are scattered on one side from the central point for providing direct drawings. By accompanied with the grooves, scales and the indication elements on the middle plate, the protractor of this invention is used to easily draw different geometric figures.