Fabrication and functionalization of magnesium nanoparticle for lipase immobilization in n-propyl gallate synthesis

• Main Authors: Abhishek Sharma, Anil Kumar, Khem Raj Meena, Shikha Rana, Mahavir Singh, Shamsher Singh Kanwar
• Format: Article
• Language: English
• Published: Elsevier 2017-10-01
• Series: Journal of King Saud University: Science
• Subjects: B. thermoamylovorans BHK67; NPs-bound lipase; Thermostability; n-Propyl gallate; Esterification; Antioxidant
• Online Access: http://www.sciencedirect.com/science/article/pii/S1018364717303968

An extracellular lipase partially purified from Bacillus thermoamylovorans BHK67 was effectively immobilized onto modified magnetic MgFe2O4 nanoparticles (NPs). NPs were prepared by the sol-gel auto-combustion method and characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Ultra-Violet–Visible Spectroscopy (UV–vis) and atomic force microscopy (AFM). Protein loading reached a saturated amount of about 0.20 mg lipase per milligram of MgFe2O4 NPs with 78.9% binding efficiency. The NPs-bound lipase also showed stability following exposure to n-propanol and iso-propanol or FeCl2 and MgCl2 metal ions at (1 mM) at 55 °C. NPs-bound lipase also retained 50% of its original hydrolytic activity even after 8th cycle, as well as after 12 h of incubation at 55 °C. NPs-bound lipase in an esterification reaction of n-propanol and gallic acid (25 mM) performed for 12 h at 55 °C produced n-propyl gallate with a conversion rate of 82%. Synthesized n-propyl gallate possessed strong antioxidant activity, which was confirmed by DPPH assay, and in addition has anticancerous activity which was tested on a human L132 cell line.