Biotransformation of p‐methoxyphenylacetonitrile into p‐methoxyphenylacetic acid by resting cells of Bacillus subtilis

Abstract

Resting cells of Bacillus subtilis ZJB-063 were used for the direct transformation of MOPAN (p-methoxyphenylacetonitrile) to MOPAA (p-methoxyphenylacetic acid), which is an important pharmaceutical intermediate. The B. subtilis ZJB-063 culture conditions for the production of nitrilase and the reaction conditions for this nitrilase-mediated conversion were optimized. The maximum production of nitrilase was achieved when glucose and a combination of ammonium sulfate and yeast powder were added as carbon and nitrogen sources respectively. Previously reported inducers were found to be unnecessary for the production of nitrilase from B. subtilis ZJB-063, which indicated that this nitrilase appeared to be constitutive. However, when epsilon-caprolactam (6-hexanolactam) was added as the inducer, B. subtilis ZJB-063 exhibited nitrile hydratase and amidase activity. The maximum conversion of MOPAN into MOPAA (specific activity 17.03 units.g(-1)(DCW); DCW is dry cell weight) was observed in a solution containing 50 mM phosphate buffer (pH 7.0), 10 mM MOPAN, 2.7 mg DCW.ml(-1) wet resting cells and 5% (v/v) DMSO for 4 h at 32 degrees C. MOPAN (10 mM) was completely converted into MOPAA (9.65 mM) in 5 h in shake flasks without the formation of p-methoxyphenylacetamide. The small deviation of MOPAA (9.65 mM) from the theoretical amount (10 mM) may be due to partial consumption of the products by B. subtilis ZJB-063. Both MOPAN and MOPAA inhibited the hydrolysis at concentrations above 15 mM. Scale up of the reaction to 200 ml in a bubble bioreactor shortened the reaction time compared with the reactions performed in shake flasks.

Enhancing Endo-nitrilase production by a newly isolated Arthrobacter nitroguajacolicus ZJUTB06-99 through optimization of culture medium

“…The values were the average of the triplicate groups. Carbon sources, nitrogen sources, and inducers were the three key factors for strain producing nitrilases [18][19][20]. The selection of medium components would be expressed in the text through traditional 'one-factor-at-a-time' approach.…”

“…The column, injection, and detector temperature were 150 o C, 220 o C, and 220 o C, respectively. One unit of nitrilase activity was defined as the amount of enzyme that catalyzed the formation of 1 µmol acrylic acid per min under standard conditions [18]. All data were performed in triplicate.…”

“…It is also found that the conversion time and the conversion of the substrate were significantly improved after the optimization. Furthermore, ZJUTB06-99 exhibited a bit higher nitrilase activity compared with other nitrilaseproducing strains such as B. subtilis ZJB-063 [18] and P. putida MTCC 5110 [19] after optimization.…”

Enantioselective biocatalytic hydrolysis of (R,S)-mandelonitrile for production of (R)-(−)-mandelic acid by a newly isolated mutant strain

“…The time course curves of 1.4 and 1.8 g l -1 cell concentrations were even overlapped which illustrated that the additional cells did not increase the reaction rate. The reason may be the mass transfer limitations caused by a higher amount of cells [4].…”

An efficient process for the transformation of betulin to betulinic acid by a strain of Bacillus megaterium

“…Besides that, biotransformation methods are more stereo-and regio-selective. Including that few reactions that cannot be easily completed thorough chemical approaches are performed by microbial transformation in an easier way (Pervaiz et al 2013;Bastos et al 2007;Liu et al 2011;Mao et al 2012;Feng et al 2013;Chen et al 2008;Shao et al 2016). Cunninghamella blakesleeana has also been investigated for biotransformation of betulin to betulinic acid analyzed by HPLC (Feng et al 2013).…”