Evaluation of product analogues for purification of penicillinase by affinity chromatography.

Among different matrices prepared, ampicilloic acid-polymer matrix offered 86.7% adsorption, 95% elution and 82.4% overall recovery of penicillinase. The structure of both the side chain and penicilloic or cephalosporoic acid moieties contribute to the affinity interactions.

Expanded bed chromatography and radial flow column chromatography: the approaches for adsorption chromatography of biomolecules on industrial scale.

Adsorption of proteins directly from unclarified feed-stocks, has gained importance in the recovery of biomolecules on Industrial scale. Adsorption in expanded beds and radial flow gives significantly better results compared to conventional column chromatography methods for downstream processing of variety of proteins from particulate-containing feed-stocks, such as fermentation broths and cells extracts. The simple operation of these techniques reduces the complexity of downstream processing by eliminating steps such as filtration, centrifugation and concentration. One step purification, with simple equipment, these techniques enable to recover pure protein with 95% yield in biotechnological industry. The principles, operating procedures, adsorbents and applications of these techniques are discussed.

Comparative evaluation of determination of beta-lactam intermediates.

The Schiff's base formation between 6-aminopenicillanic acid, 7-aminodesacetoxycephalosporanic acid and 7-aminocephalosporanic acid and p-dimethylaminobenzaldehyde (PDAB) was investigated. The factors that affect the reaction such as concentration of PDAB, time and pH were studied and optimised for estimation of these intermediates.

Cephalosporin acylases: enzyme production, structure and application in the production of 7-ACA.

Cephalosporin acylases have application in the production of 7-aminocephalosporanic acid which forms a key raw material for the preparation of semisynthetic injectable cephalosporins. The enzymes are of industrial importance and hyperproducing genetically engineered strains have been constructed. Different aspects of these enzymes such as subunit structure, post translational modification, primary structure, substrate specificity and their importance in pharmaceutical industry are discussed.

Production of extracellular acidic lipase by Rhizopus arrhizus as a function of culture conditions.

Thermophilic strain of Rhizopus arrhizus accumulates an acidic lipase in culture fluid when grown in a medium containing ground nut oil, milk powder and inorganic salts. Addition of 2.0% ground nut oil yielded the highest productivity of enzyme. Soyabean meal and arabinose were found to be the best nitrogen and carbon sources for enzyme production respectively. Addition of metal ions such as MnCl2, SnCl2 and CaCl2 increased the enzyme productivity by 4 fold. The enzyme productivity in the fermenter was much higher (310 U/ml) than in shake-flask (180 U/ml). Crude lipase preparation showed pH and temperature activity optima at 3.5 and 45 degrees C respectively. The enzyme is thermostable and highly active in hydrolysing triglycerides and failed to hydrolyse-methyl esters of caprylate and palmitate.

Persistence of Candida sp. 115 during hydrolysis of penicillin G and metabolism of phenylacetic acid.

The growth of Candida sp. 115 was investigated on the constituents of penicillin G hydrolysis reaction mixture. Neither penicillin G nor 6-aminopenicillanic acid was degraded or utilised for growth. The yeast accepted phenylacetic acid, sodium acetate and glucose as growth substrates. Phenylacetic acid was metabolised via p-hydroxy phenylacetic acid, which was the only accumulated metabolite. The enzymes responsible for hydroxylation of phenylacetic acid were induced by phenylacetic acid and sodium acetate.

Enzymatic hydrolysis of 7-phenylacetamidodesacetoxycephalosporanic acid by immobilized penicillin G acylase.

Enzymatic parameters such as pH, temperature and substrate concentration were studied for the hydrolysis of 7-PADCA by penicillin G acylase. Optimum pH and temperature were 8.0 and 50 degrees C, respectively. Km value of soluble and immobilized enzyme for 7-PADCA was 2.3 x 10(-5) M and 7.5 x 10(-5) M, respectively. At 7-PADCA concentration of 5% and an IME: 7-PADCA ratio of 1:2.5, the hydrolysis was complete in 110 min.