Effect of cross-linked enzyme aggregate strategy on characterization of sn-1,3 extracellular lipase from Aspergillus niger GZUF36
| Autor: | Xuefeng Zeng, Yangyang Cai, Cuiqin Li, Shuqi Xing, Ruonan Zhu, Laping He, Cuicui Chen |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Cross-linked enzyme aggregate
Applied Microbiology and Biotechnology Catalysis 03 medical and health sciences chemistry.chemical_compound Enzyme Stability Lipase 030304 developmental biology 0303 health sciences biology 030306 microbiology Aspergillus niger Temperature Substrate (chemistry) General Medicine Hydrogen-Ion Concentration Enzymes Immobilized biology.organism_classification chemistry Glutaral Emulsion biology.protein Glutaraldehyde Selectivity Biotechnology Nuclear chemistry |
| Zdroj: | Applied Microbiology and Biotechnology. 105:1925-1941 |
| ISSN: | 1432-0614 0175-7598 |
| DOI: | 10.1007/s00253-021-11160-x |
| Popis: | Background: A novel Aspergillus. niger strain GZUF36 with two high sn-1,3 position selectivity of lipases, including an intracellular lipase and an extracellular one was selected from oil-rich soil in our previous work. The sn-1,3 extracellular lipase from Aspergillus niger GZUF36 (EXANL1) has important potential applications. However, the structure and properties of this lipase need further study for its better application, the immobilization of enzyme is an effective method to study its structural properties and obtain the best catalytic properties. Cross-linked enzyme aggregates (CLEAs) have been widely used in carrier-free immobilization technologies because of their low cost and fast preparation. To this end, it is necessary to investigate the effect of CLEAs strategy on the characteristics, secondary structure, and positional selectivity of EXANL1 before and after immobilization.Results: The CLEAs of purified EXANL1 (CLEA-EXANL1) was achieved optimum activity recovery (100.3±1.1%) with 80% tert-butanol as the precipitant, a glutaraldehyde (GA) concentration of 30 mM, a GA treatment time of 1.5 h, and a centrifugal speed of 6000 g. CLEA-EXANL1 exhibited a broader optimum pH range (4–6) compared with free EXANL1 (6.5). CLEA-EXANL1 presented optimum activity at 40 °C, which was 5 °C higher than that of free EXANL1. CLEAs strategy decreased the maximum reaction rate and increased the Michaelis–Menten constant of EXANL1 when olive oil emulsion was used as a substrate. Moreover, after 30 days, free EXANL1 lost more than 80.0% of its activity, whereas CLEA-EXANL1 retained more than 90.0% of its activity. CLEAs strategy improved the tolerance of EXANL1 in polar organic solvents. Fourier transform infrared spectroscopy results showed that the CLEAs technique increased the content of the β-sheets and β-turns of EXANL1 and reduced α-helixes and irregular crimp contents. CLEAs strategy did not change the sn-1,3 selectivity of EXANL1.Conclusion: The effect of CLEAs technology on catalytic properties, structure, selectivity and other characteristics of the EXANL1 was comprehensively explored, which laid a foundation for its subsequent rational transformation and industrial application. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|