The reaction time was 30 min, 1.13 g/1 of 6-CHP was formed.

4.3. Course of 6-CHP production

6-CHP was produced by C. testosteroni MCI2848 under the conditions optimized as described above. Since the reaction was injured by the presence of 20 g/1 of 3-CP or more, it was important to maintain the optimum concentration of 3-CP through successive feeding. The reaction was allowed to proceed at 30 °C for 40 h by keeping the concentration of 3-CP below 2%. Figure 1 illustrates a typical course of 6-CHP production from 3-CP by intact cells of the strain cultured at 30°C for 18 h in the presence of 6-chloronicotinic acid (2.5 g/1). The addition of 5 mM NA to the reaction mixture increased the rate of 6-CHP production, and enabled 1.5 times higher accumulation of 6-CHP than that without it. A total of 57.2 g of 6-CHP per liter was produced after 40 h of reaction and the residual 3-CP was 5.5 g/1. The molar yield of 6-CHP was 90% and the selectivity was 100%. The solubility of 6-CHP is so low (3 g/1, pH7.0, 30°C) that the reaction mixture became muddy with the precipitated 6-CHP, which makes the purification of the product to be easy. No other by-product was accumulated in the reaction mixture.

New methods for the production of 3,6-substituted pyridine compounds have been investigated for practical application in the industry.10111 C. testosteroni provided a new industrial process for the production of pyridine derivatives.

Figure 1. Course of 6-CHP production from 3-CP (#) with or ( ) without addition of 5mM NA.

Time (hrs)

Figure 1. Course of 6-CHP production from 3-CP (#) with or ( ) without addition of 5mM NA.

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