Abstract: A process for the production of a 4-halo-3-hydroxybutyronitrile which comprises reacting a 1,3-dihalo-2-propanol with a dehalogenating enzyme originating from a Corynebacterium or a Microbacterium in the presence of an alkali cyanide to thereby convert the 1,3-dihalo-2-propanol into the 4-halo-3-hydroyxbutyronitrile and collecting the product thus formed is disclosed. According to this process, a 4-halo-3-hydroxybutyronitrile which is highly useful in the syntheses of various medicines and physiologically active substances can be easily and efficiently produced from an inexpensive starting material.

Abstract: A process for preparing an optically active (R)-(-)-3-halo-1,2-propanediol comprising reacting an epihalohydrin with an epihalohydrin hydratase originating from a microorganism. For example, the microorganism belongs to the genus Corynebacterium or the genus Microbacterium. Epihalohydrins which can be used include epichlorohydrin and epibromohydrin. The reaction can be carried out at a temperature of from 5.degree. to 50.degree. C. and a pH of from 4 to 10.

Abstract: An improved biological conversion of a nitrile such as acrylonitrile or a cyanopyridine into the corresponding carboxylic acid such as acrylic acid or a nicotinic acid by the action upon the nitrile of a nitrilase enzyme, in which the improvement resides in the use as the source of the enzyme of a microorganism of Rhodococcus, such as Rh. rhodochrous J-1, FERM BP-1478, which is cultured in the presence of a lactam compound.

Abstract: A process for the production of an optically active (R)-(-)-3-halo-1,2-propanediol which comprises contacting a 1,3-dihalo-2-propanol with a dehalogenase originating from a microorganism belonging to the genus Corynebacterium or Microbacterium. This process makes it possible to produce the (R)-(-)-3-halo-1,2-propanediol, which is highly useful as a starting material in the synthesis of various drugs and physiologically active substances, theoretically at a yield of 100%.