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For the production of 6-hydroxynicotinic acid from nicotinic acid, bacteria capable of assimilating nicotinic acid as a sole carbon, nitrogen and energy source were isolated from soils. Among them, SH-007, newly isolated strain having the best acitivity of nicotinic acid hydroxylase was selected and identified as Pseudnmonas sp. The specific acitivity of nicotinic acid hydroxylase of Pseudomonas sp. was highest when the strain was cultured at 30℃ for 24 hrs in the medium (pH 7.5) containing 2 g nicotinic acid, 1 g (NH₄)₂SO₄, and 0.5 g peptone per liter. The addition of 1.5 g/ℓ of nicotinic acid into the 24 hrs incubated culture medium resulted in the 12% higher specific activity of nicotinic acid hydroxylase than that of the non-added control after further 18 hrs incubation. In the 6-hydroxynicotinic acid production through the reaction with resting cells, 2.22 g/ℓ of 6-hydroxynicotinic acid was produced from 2 g/ℓ of nicotinic acid after incubation of 3 hrs under optimum conditions, which correpsonds to 98.2% of theoretical 6-hydroxynicotinic acid yield.
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