Synthesis of vanillic acid using whole cell nitrilase of wild and mutant Gordonia terrae
2016
Bhalla, Tek Chand | Purushottama Praśānta, | Kumari, Nisha | Kumar, Vijay | Kumar, Virender | Savitri,
The resting cells of Gordonia terrae mutant E9 having enhanced nitrilase activity were used for biotransformation of 4-hydroxy-3-methoxybenzonitrile into vanillic acid. The maximum conversion was observed in 0.1 M phosphate buffer (pH 8.0), using 60 mM substrate and 0.75 mgDCW resting cells in 1 mL reaction at 40 °C. K ₘ of the whole cell nitrilase of wild and mutant strains of G. terrae for this substrate were 20 and 16.6 mM, and V ₘₐₓ were 0.19 and 0.95 [Formula: see text], respectively. Fed batch reaction for transformation of 4-hydroxy-3-methoxybenzonitrile using whole cell nitrilase of wild G. terrae resulted in 2.36 g of vanillic acid in 5 h with a catalytic and volumetric productivity of 0.78 [Formula: see text] and 4.72 gL⁻¹h⁻¹, respectively. The whole cell nitrilase of G. terrae mutant E9 resulted in higher catalytic and volumetric productivity, i.e., 1.68 [Formula: see text] and 10 gL⁻¹h⁻¹. A total 5.04 g of vanillic acid with 99 % purity were accumulated in 100 mL of reaction after 5 h.
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