CELLULASE IMMOBILIZATION ON POLY(METHYL METHACRYLATE) NANOPARTICLES BY MINIEMULSION POLYMERIZATION

Patrícia Simon,Antônio Augusto U De Souza,Alexsandra Valério,Janaína S Lima,Débora De Oliveira,Claudia Sayer,Selene M A Guelli U De Souza Souza,Pedro H.H Araújo

doi:10.1590/0104-6632.20180352s20160094

Patrícia Simon, Antônio Augusto U De Souza + Show 6 more

Open Access

https://doi.org/10.1590/0104-6632.20180352s20160094

Copy DOI

Abstract

Abstract Cellulases are efficient enzymes for the conversion of cellulose into glucose. Their use in immobilized form enables them to be reused in successive cycles in many biotechnological processes. Unlike conventional methods of immobilization by covalent bonding, in miniemulsion polymerization the immobilization of enzyme and the synthesis of polymer nanoparticles (support) occur simultaneously. Based on these aspects, the immobilization of cellulose on poly(methyl methacrylate) (PMMA) nanoparticles by miniemulsion polymerization was studied. The surfactant type (non-ionic and ionic) and latex pH showed great influence on cellulase activity. High activity values were obtained only when non-ionic surfactant (Lutensol AT50) and buffering agent (NaHCO3) were used simultaneously. MMA polymerization rate and final monomer conversion were not affected by the presence of cellulase. The maximum immobilization efficiency (60%) was obtained when 6 wt.% of cellulase was used and stable PMMA nanoparticles (133 nm) were obtained. The relative activity profile of immobilized cellulase, for pH as well as temperature, was similar to that reported for the free form. Immobilized enzyme keeps its activity throughout seven days when stored at 4 oC and phosphate buffer pH 6.0. Based on the results obtained in this work, miniemulsion polymerization as a method for cellulase immobilization on PMMA nanoparticles showed to be a promising technique with high possibility of industrial application.

Highlights

Due to their biotechnological potential, cellulases contribute to the improvement of several processes, including food, textile, paper and cellulose industries, agriculture and, more recently, second-generation ethanol production
Aiming to contribute with the development of effective and innovative cellulase immobilization techniques, this paper presented a study of immobilization of a commercial cellulase on poly(methyl methacrylate) (PMMA) nanoparticles during miniemulsion polymerization
The cellulase activity was determined by the DNS method, following the procedure described: 900 μL of 4% (m/v) CMC solution, in phosphate buffer (0.05 M, pH 6.0), and 100 μL of PMMA-cellulase colloidal suspension were incubated at 55 oC for 30 minutes

Summary

INTRODUCTION

Due to their biotechnological potential, cellulases contribute to the improvement of several processes, including food, textile, paper and cellulose industries, agriculture and, more recently, second-generation ethanol production. The most common ways to link an enzyme to nanoparticles are through electrostatic adsorption, covalent attachment to surface modified nanoparticles, direct conjugation to the nanoparticle surface and conjugation using specific affinity of protein (Ahmad and Sardar, 2015; Sheldon and Van Pelt, 2013; Elnashar, 2010) These approaches generally involve at least two steps, one for obtaining the support and another for enzyme immobilization, which usually requires a lot of time. Valério et al (2015) immobilized lipase CalB on well-defined PMMA core-shell nanoparticles during free radical miniemulsion polymerization. Aiming to contribute with the development of effective and innovative cellulase immobilization techniques, this paper presented a study of immobilization of a commercial cellulase on PMMA nanoparticles during miniemulsion polymerization

MATERIALS AND METHODS

RESULTS AND DISCUSSION

CONCLUSIONS