抄録
Recent progresses in the microbial production of vitamins and their related compounds were out lined. A new optical resolution process for racemic pantolactone, a chiral building block for the commer cial production of D-pantothenic acid, has been developed. In this optical resolution, a novel micro bial enzyme, lactonohydrolase, which was found in a fungus Fusarium oxisporum is used. The en zyme catalyzes hydrolysis of only the D-enantiomer in the racemic mixture. Thus, DL-pantolactone is easily separated into D-pantoic acid and L-pantolactone. Nitrile hydratase of Rhodococcus rhodochrous J1 catalyzes hydration of a various kind of ali phatic and aromatic nitriles. 3-Cyanopyridine, a starting substance for the commercial production of nicotinamide, is also efficiently converted to the corresponding amide, nicotinamide by the enzyme. Since the by-product formation from the produced nicotinamide, which is unavoidable in the conven tional chemical process, does not occur, the process using this enzyme is highly practical. The same organism produces nitrilase under the different culture conditions to those of nitrile hydratase produc tion. The enzyme is useful for the conversion of 3-cyanopyridine to nicotinic acid. Mycelia of a filamentous fungus Mortierella alpina 1 S-4 are practical source of triacylglycerols rich in arachidonic acid (AA). Under the suitable culture conditions, the oil accumulated by the fun gus reaches 500 〜 600 mg/g dry mycelia (13.5 g/l). The oil contains 30 〜 70%AA in the total fatty acids. Mutants derived from M. alpina 1 S-4 and defective in desaturases of AA biosynthesis are useful for the production of oils containing n-9 or n-3 polyunsaturated fatty acids.
