Enantiomerically pure D-phenylglycine production using immobilized Pseudomonas aeruginosa 10145 in calcium alginate beads

Abstract

Em trabalhos anteriores em nosso laboratório, uma cepa de Pseudomonas aeruginosa demonstrou ter atividade enzimática na conversão de arilaminonitrilas em D-amino ácidos. Essa atividade enzimática aumentou por indução de modo a produzir D-fenilglicina enantiomericamente pura a partir de 2-fenil-2-aminoacetonitrila. No presente trabalho, as melhores condições para essa transformação são descritas. Para aumentar o uso potencial desse biocatalisador, células de Pseudomonas aeruginosa 10145 foram envolvidas em alginato em forma de pequenas esferas. Duas concentrações diferentes de alginato foram usadas nesse processo. A morfologia das pérolas foi analisada via microscopia eletrônica de varredura (MEV). As pérolas com altas porosidades, formadas com 1,5% de alginato de sódio conduziram às melhores conversões de 2-fenil-2-aminoacetonitrila em D-fenilglicina (20%, 3,0 horas de reação e excesso enantiomérico superior a 98%). Repetições em quatro bateladas consecutivas demonstraram a manutenção da atividade desse sistema catalítico.In a preliminary work in our laboratory, a Pseudomonas aeruginosa strain was found to have enzymatic activity to convert arylaminonitriles into D-amino acids. This enzymatic activity was increased by induction to produce enantiomerically pure D-phenylglycine using 2-phenyl-2-aminoacetonitrile as starting material. In this work, the best conditions leading to this transformation are described. In order to increase the biocatalyst potential use, cells of Pseudomonas aeruginosa 10145 were entrapped in calcium alginate gel beads. Two different concentration of sodium alginate were used to immobilize these cells. Beads morphology was demonstrated by scanning electron microscopy (SEM). The beads with higher porosity, formed with 1.5% (m/v) of sodium alginate led to the best conversion of 2-phenyl-2-aminoacetonitrile into D-phenylglycine (20% of conversion, 3.0 h of reaction enantiomeric excess higher than 98%). Recycling was performed in four repeated batch reactions, which proved the biocatalyst activity maintenance.

Development of a new antibacterial biomaterial by tetracycline immobilization on calcium-alginate beads

“…SEM images of calcium alginate at different zooms, given in Fig. 10, have been seen exhibited similarity with SEM images of calcium alginate in literature (Alonso, Antunes, & Oestreicher, 2007). When SEM images of calcium alginate beads were compared with SEM images of tetracycline immobilized calcium alginate, given in Fig.…”

Degradation of phenol by Rhodococcus pyridinivorans GM3 immobilization

“…A typical concentration of 3% w/v of sodium alginate with 0.2 M CaCl2 2H2O solution to create synthetic Ca-alginate beads was supporting phenol degradation which also emphasizes the structural stability of Ca-alginate beads (Figure 2). The permeability of beads is impacted by the concentration of Na and resulting in much porosity when diluting with Na sodium alginate is used to form the beads, whilst increased sodium alginate lead to the structure stability of beads [21]. Thus, the encapsulated Pseudomonas putida in Ca-alginate beads that high mechanical strength produced decreased efficacy for biodegradation of phenol, hence, the best way as the author sought is immobilization as it could close the polluted cells going to the environment [22].…”

Production of chiral compounds using immobilized cells as a source of biocatalysts

“…Recycling study was performed in four repeated batches, and the enzyme activity was maintained almost the same (Scheme 49). 76 Scheme 47 Lactam hydrolysis catalyzed by immobilized cells of Microbacterium hydrocarbonoxydans L29-9. Ko et al have immobilized whole cells of Pseudomonas fluorescens IFO 12055 in calcium alginate for the synthesis of S-acetyl-2-methylpropionic acid from the enantioselective hydrolysis of methyl-β-acetylthioisobutyrate.…”