Effects of additives on lipase immobilization in microemulsion-based organogels.
An inexpensive, facile, and environmentally benign method was developed to improve the activity and stability of Candida rugosa lipase (triacylglycerol acylhydrolase) immobilized on microemulsion-based organogels (CRL MBGs) via the addition of additives during immobilization. The additives used were polyethylene glycol (PEG) or polysaccharides. This study is the first report on the effect of additives in CRL MBGs. Among the tested additives, PEG produced the most improvement in the immobilized CRL, enhancing its stability in organic solvents (specifically polar solvents). The results of circular dichroism and fluorescence spectra experiments indicated that exposure of the acidic CRL to electronegative additives in the buffer, such as polyethylenimine and the electropositive surfactant cetyltrimethylammonium bromide, may change the lipase secondary structure, ultimately causing enzyme inactivation. However, sodium bis(2-ethylhexyl)sulfosuccinate and PEG 2000 had minimal effects on the secondary structure of CRL. The CRL MBGs containing PEG 2000 demonstrated remarkable retention of their catalytic activity during the recycling test. No significant changes in enzymatic activity were observed, even after nine runs, and 90% of the original yield was maintained after 15 cycles.
Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, People's Republic of China.
Wei-Wei
WW
Zhang
Na
N
Wang
Ling
L
Zhang
Wan-Xia
WX
Wu
Cheng-Li
CL
Hu
Xiao-Qi
XQ
Yu
D002175:Candida / Q000737:chemistry* / Q000201:enzymology; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D004143:Dioctyl Sulfosuccinic Acid / Q000737:chemistry; D004655:Emulsions; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry*; D017743:Equipment Reuse; D005656:Fungal Proteins / Q000737:chemistry*; D005782:Gels; D008049:Lipase / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011094:Polyethyleneimine / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D055672:Static Electricity
D002593:Cetrimonium Compounds; D004655:Emulsions; D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D005782:Gels; D011134:Polysaccharides; D004143:Dioctyl Sulfosuccinic Acid; D011092:Polyethylene Glycols; D011094:Polyethyleneimine; D008049:Lipase; D000077286:Cetrimonium