{"title":"Kinetic and thermodynamic studies on the thermal inactivation of lipase immobilized on glutaraldehyde-activated rice husk silica","authors":"Iara C. A. Bolina, Adriano A. Mendes","doi":"10.1007/s10529-023-03449-w","DOIUrl":null,"url":null,"abstract":"<p>The objective of this study was to obtain sufficient information on the thermal stabilization of a food-grade lipase from <i>Thermomyces lanuginosus</i> (TLL) using the immobilization technique. To do this, a new non-porous support was prepared via the sequential extraction of SiO<sub>2</sub> from rice husks, followed by functionalization with (3-aminopropyl) triethoxysilane – 3-APTES (Amino–SiO<sub>2</sub>), and activation with glutaraldehyde – GA (GA-Amino-SiO<sub>2</sub>). We evaluated the influence of GA concentration, which varied from 0.25% v v<sup>−1</sup> to 4% v v<sup>−1</sup>, on the immobilization parameters and enzyme thermal stabilization. The thermal inactivation parameters for both biocatalyst forms (soluble or immobilized TLL) were calculated by fitting a non-first-order enzyme inactivation kinetic model to the experimental data. According to the results, TLL was fully immobilized on the external support surface activated with different GA concentrations using an initial protein load of 5 mg g<sup>−1</sup>. A sharp decrease of hydrolytic activity was observed from 216.6 ± 12.4 U g<sup>−1</sup> to 28.6 ± 0.9 U g<sup>−1</sup> of after increasing the GA concentration from 0.25% v v<sup>−1</sup> to 4.0% v v<sup>−1</sup>. The support that was prepared using a GA concentration at 0.5% v v<sup>−1</sup> provided the highest stabilization of TLL – 31.6-times more stable than its soluble form at 60 °C. The estimations of the thermodynamic parameters, e.g., inactivation energy (E<sub>d</sub>), enthalpy (ΔH<sup>#</sup>), entropy (ΔS<sup>#</sup>), and the Gibbs energy (ΔG<sup>#</sup>) values, confirmed the enzyme stabilization on the external support surface at temperatures ranging from 50 to 65 °C. These results show promising applications for this new heterogeneous biocatalyst in industrial processes given the high catalytic activity and thermal stability.</p>","PeriodicalId":8929,"journal":{"name":"Biotechnology Letters","volume":"1 1","pages":""},"PeriodicalIF":2.0000,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biotechnology Letters","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1007/s10529-023-03449-w","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIOTECHNOLOGY & APPLIED MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The objective of this study was to obtain sufficient information on the thermal stabilization of a food-grade lipase from Thermomyces lanuginosus (TLL) using the immobilization technique. To do this, a new non-porous support was prepared via the sequential extraction of SiO2 from rice husks, followed by functionalization with (3-aminopropyl) triethoxysilane – 3-APTES (Amino–SiO2), and activation with glutaraldehyde – GA (GA-Amino-SiO2). We evaluated the influence of GA concentration, which varied from 0.25% v v−1 to 4% v v−1, on the immobilization parameters and enzyme thermal stabilization. The thermal inactivation parameters for both biocatalyst forms (soluble or immobilized TLL) were calculated by fitting a non-first-order enzyme inactivation kinetic model to the experimental data. According to the results, TLL was fully immobilized on the external support surface activated with different GA concentrations using an initial protein load of 5 mg g−1. A sharp decrease of hydrolytic activity was observed from 216.6 ± 12.4 U g−1 to 28.6 ± 0.9 U g−1 of after increasing the GA concentration from 0.25% v v−1 to 4.0% v v−1. The support that was prepared using a GA concentration at 0.5% v v−1 provided the highest stabilization of TLL – 31.6-times more stable than its soluble form at 60 °C. The estimations of the thermodynamic parameters, e.g., inactivation energy (Ed), enthalpy (ΔH#), entropy (ΔS#), and the Gibbs energy (ΔG#) values, confirmed the enzyme stabilization on the external support surface at temperatures ranging from 50 to 65 °C. These results show promising applications for this new heterogeneous biocatalyst in industrial processes given the high catalytic activity and thermal stability.
期刊介绍:
Biotechnology Letters is the world’s leading rapid-publication primary journal dedicated to biotechnology as a whole – that is to topics relating to actual or potential applications of biological reactions affected by microbial, plant or animal cells and biocatalysts derived from them.
All relevant aspects of molecular biology, genetics and cell biochemistry, of process and reactor design, of pre- and post-treatment steps, and of manufacturing or service operations are therefore included.
Contributions from industrial and academic laboratories are equally welcome. We also welcome contributions covering biotechnological aspects of regenerative medicine and biomaterials and also cancer biotechnology. Criteria for the acceptance of papers relate to our aim of publishing useful and informative results that will be of value to other workers in related fields.
The emphasis is very much on novelty and immediacy in order to justify rapid publication of authors’ results. It should be noted, however, that we do not normally publish papers (but this is not absolute) that deal with unidentified consortia of microorganisms (e.g. as in activated sludge) as these results may not be easily reproducible in other laboratories.
Papers describing the isolation and identification of microorganisms are not regarded as appropriate but such information can be appended as supporting information to a paper. Papers dealing with simple process development are usually considered to lack sufficient novelty or interest to warrant publication.