Butyl ferulate was synthesized using a silica-immobilized commercial lipase (Steapsin) in dimethylsulfoxide (DMSO). Lipase-immobilized by surface adsorption onto silica pretreated with 1% glutaraldehyde showed 89% binding of protein. The esterification of butanol (100 mM) and ferulic acid (50 mM) by silica-bound biocatalyst was carried out at 45 ̊C for 6 h under shaking (120 rpm). The optimizati...

Recent studies exploring the relationship between enzymatic catalysis and protein dynamics in the aqueous phase have yielded evidence that dynamics and enzyme activity are strongly correlated. Given that protein dynamics are significantly attenuated in organic solvents and that proteins exhibit a wide range of motions depending on the specific solvent environment, the nonaqueous milieu provides...

Background. Production of highly pure enantiomers of vicinal diols is desirable, but difficult to achieve. Enantiomerically pure diols and acyloins are valuable bulk chemicals, promising synthones and potential building blocks for chiral polymers. Enzymatic reduction of ketones is a useful technique for the synthesis of the desired enantiomeric alcohols. Here, we report on the characterization ...

Immobilized Candida antarctica lipase B, Novozym 435, was used as the biocatalyst in the esterification of adipic acid with four different isomers of butanol (n-butanol, sec-butanol, iso-butanol, and tert-butanol). Optimum conditions for the synthesis of adipate esters were obtained using response surface methodology approach with a four-factor-five-level central composite design concerning imp...

Acetoin (3-hydroxy-2-butanone), an extensively-used food spice and bio-based platform chemical, is usually produced by chemical synthesis methods. With increasingly requirement of food security and environmental protection, bio-fermentation of acetoin by microorganisms has a great promising market. However, through metabolic engineering strategies, the mixed acid-butanediol fermentation metabol...

BACKGROUND The high costs of pyridine nucleotide cofactors have limited the applications of NAD(P)-dependent oxidoreductases on an industrial scale. Although NAD(P)H regeneration systems have been widely studied, NAD(P)(+) regeneration, which is required in reactions where the oxidized form of the cofactor is used, has been less well explored, particularly in whole-cell biocatalytic processes. ...

The synthesis of citronellyl butyrate by direct esterification reaction catalyzed by immobilized lipase from Candida rugosa was studied in a continuous packed bed reactor using n-hexane as organic solvent. Parameters such as residence time, temperature, and pH were examined. The optimum conversion was obtained at a flow rate of 1 ml/min (residence time 8 min), temperature of 50 °C, and pH 7.5. ...

Penicillin G acylase from E. coli TA1 was immobilized by Cross-Linked Enzyme Aggregates (CLEA), a new method for immobilization. This biocatalyst and commercial immobilized penicillin G acylase (PGA-450) were used to study the effect of pH, temperature and substrate concentration on the synthesis of ampicillin from phenyl glycine methyl ester (PGME) and 6-aminopenicillanic acid (6-APA). Compare...

The C-C bond formation is an important reaction in organic synthesis to obtain value-added intermediates. Therefore, in this paper an attempt has been made to accelerate the Henry reaction (C-C bond formation) between aryl aldehydes and nitromethane using less expensive whole cell biocatalyst, baker’s yeast (BY). The scope of the methodology was also tested for the heteryl aldehyde i.e. 2-chlor...