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Properties of poly(AAc‐ co ‐HPMA‐ cl ‐EGDMA) hydrogel‐bound lipase of Pseudomonas aeruginosa MTCC‐4713 and its use in synthesis of methyl acrylate
Author(s) -
Singh Kanwar Shamsher,
Lal Verma Madan,
Maheshwari Chanchal,
Chauhan Sandeep,
Singh Chimni Swapandeep,
Singh Chauhan Ghansham
Publication year - 2007
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.25315
Subject(s) - lipase , hydrolysis , methyl acrylate , chemistry , polymer chemistry , heptane , acrylate , methanol , organic chemistry , nuclear chemistry , enzyme , copolymer , polymer
Microbial lipases (E.C. 3.1.1.3) are preferred biocatalysts for the synthesis of esters in organic solvents. Various extracellular thermoalkaliphilic lipases have been reported from Pseudomonas sp. In the present study, a purified alkaline thermoalkalophilic extracellular lipase of Pseudomonas aeruginosa MTCC‐4713 was efficiently immobilized onto a synthetic poly(AAc‐ co ‐HPMA‐ cl ‐EGDMA) hydrogel by adsorption and the bound lipase was evaluated for its hydrolytic potential towards various p ‐nitrophenyl acyl esters varying in their C‐chain lengths. The bound lipase showed optimal hydrolytic activity towards p ‐nitrophenyl palmitate ( p ‐NPP) at pH 8.5 and temperature 45°C. The hydrolytic activity of the hydrogel‐bound lipase was markedly enhanced by the presence of Hg 2+ , Fe 3+ , and NH 4 +salt ions in that order. The hydrogel‐immobilized lipase (25 mg) was used to perform esterification in various n ‐alkane(s) that resulted in ∼ 84.9 m M of methyl acrylate at 45°C in n ‐heptane under shaking (120 rpm) after 6 h, when methanol and acrylic acid were used in a ratio of 100 m M :100 m M , respectively. Addition of a molecular sieve (3Å × 1.5 mm) to the reaction system at a concentration of 100 mg/reaction vol (1 mL) resulted in a moderate enhancement in conversion of reactants into methyl acrylate (85.6 m M ). During the repetitive esterification under optimum conditions, the hydrogel‐bound lipase produced 71.3 m M of ester after 10th cycle of reuse. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 183–191, 2007