ABSTRACT
Penicillin G acylase was immobilized onto iron oxide nanoparticles coated with polyethyleneimine and then cross linked with glutaraldehyde solution. The FTIR spectrum of immobilized enzyme showed peak at 1648cm-1 which can be attributed to the C=N bonds of Schiff’s base linkage formed between glutaraldehyde and amino group of penicillin G acylase. By considering the FTIR spectrum of nano particle coated with polyethyleneimine, adsorption of penicillin G acylase has taken place and then glutaraldehyde cross linked enzyme onto activated support. Catalytic properties of nano penicillin G acylase were improved upon immobilization as compared to its free counterpart. The optimal pH and temperature were determined to be 7.0, 10.0, 50 and 75ºC for free and immobilized penicillin G acylase, respectively. Thermal stabilities of both nano and free penicillin G acylase were studied .The Km value of immobilized nanozyme was calculated from Lineweaver Burck plot to be 0.23 μM while that of free penicillin G acylase was 0.28μM. In this way nano penicillin G acylase with improved catalytic properties was developed as compared to its soluble counterpart.
ABSTRACT
A crude phenolic glycolipid extract from Mycobacterium bovis BCG was fractionated by column chromatography. A reversed-phase high performance liquid chromatography [HPLC] method with UV detection at 275nm was developed for simultaneous detection and separation of phenolic glycolipids [PGLs] in Mycobacterium bovis BCG. This analysis provides a good resolution. Different solvent systems and columns for HPLC were compared. A system composed of acetonitrile-water in the ratio of 0.80% at a flow rate of 0.8 mL/min and C8 analytical column were found to be optimum for HPLC of the phenolic glycolipids. This simple method is therefore appropriate to purify these compounds present in M. bovis extract