Immobilization of marine fungi on silica gel, silica xerogel and chitosan for biocatalytic reduction of ketones

• Published in: Journal of molecular catalysis. B, Enzymatic Enzymatic, 2012-12, Vol.84, p.160-165
• Main Authors: Rocha, Lenilson Coutinho, de Souza, Adriano Lopes, Rodrigues Filho, Ubirajara Pereira, Campana Filho, Sergio Paulo, Sette, Lara Durães, Porto, André Luiz Meleiro
• Format: Article
• Language: English
• Subjects: alcohols; Aspergillus; Aspergillus sclerotiorum; Biocatalysis; Bioconversions. Hemisynthesis; Biological and medical sciences; Biotechnology; catalytic activity; chitosan; enantiomers; Fundamental and applied biological sciences. Psychology; hyphae; immobilized cells; ketones; marine fungi; Methods. Procedures. Technologies; mycelium; Penicillium citrinum; Scanning electron microscopy; silica gel; Whole living cells
• ISSN: 1381-1177; 1873-3158
• DOI: 10.1016/j.molcatb.2012.05.025

Whole living cells of P. citrinum immobilized on chitosan for reduction of ketones. [Display omitted] ► Immobilization of whole living cells marine fungi on support matrices of silica gel, silica xerogel and chitosan. ► Penicilllum citrinum immobilized on chitosan catalyzed efficiently the reduction of ketones. ► Scanning electron microscopy showed a strong interaction between chitosan and the mycelium of P. citrinum. The scanning electron microscopy (SEM) analysis showed that whole living hyphal of marine fungi Aspergillus sclerotiorum CBMAI 849 and Penicillium citrinum CBMAI 1186 were immobilized on support matrices of silica gel, silica xerogel and/or chitosan. P. citrinum immobilized on chitosan catalyzed the quantitative reduction of 1-(4-methoxyphenyl)-ethanone (1) to the enantiomer (S)-1-(4-methoxyphenyl)-ethanol (3b), with excellent enantioselectivity (ee>99%, yield=95%). Interestingly, ketone 1 was reduced with moderate selectivity and conversion to alcohol 3b (ee=69%, c 40%) by the free mycelium of P. citrinum. This free mycelium of P. citrinum catalyzed the production of the (R)-alcohol 3a, the antipode of the alcohol produced by the immobilized cells. P. citrinum immobilized on chitosan also catalyzed the bioreduction of 2-chloro-1-phenylethanone (2) to 2-chloro-1-phenylethanol (4a,b), but in this case without optical selectivity. These results showed that biocatalytic reduction of ketones by immobilization hyphal of marine fungi depends on the xenobiotic substrate and the support matrix used.