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.

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.

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, partial purification and characterisation of amyloglucosidase from a new variety of Aspergillus candidus Link var. aureus.

The production of amyloglucosidase by a new variety of Aspergillus candidus was studied on various natural carbon and nitrogen nutrient sources. Jowar starch and peanut meal were found to be the best nutrient sources of carbon and nitrogen respectively. The maximum enzyme productivity was observed at pH 6.5 and temperature 32 degrees C. Sodium fluoride was found to inhibit enzyme amyloglucosidase to an extent of 85%. Addition of trace metals viz. Zinc, copper and potassium in the medium impaired the production of the enzyme. A four fold purification of the enzyme was achieved with ammonium sulphate precipitation. The partially purified enzyme gave 84% conversion efficiency of starch to glucose in 10% starch solution without the addition of liquefying enzyme.

Production of carbohydrases by Sclerotium rolfsii.

Coproduction of alpha-amylase, beta-amylase, amyloglucosidase, cellulase, xylanase, pectinase and beta-galactosidase by Sclerotium rolfsii was studied on various polysaccharides. Starch induced alpha-amylase, beta-amylase, amyloglucosidase and beta galactosidase; cellulose induced cellulase, xylanase, pectinase and beta-galactosidase; and pectin induced pectinase and beta-galactosidase. None of the enzymes studied except beta-galactosidase were induced on xylan. Group controlled mechanism for production of carbohydrases by Sclerotium rolfsii is suggested.

Role of side chain moiety in the hydrolysis of penicillins by beta-lactamase.

Various beta-lactam compounds and structurally related moieties were examined as substrates of beta-lactamase from Bacillus cereus 5/B NCTC 9946. The enzyme was specific for penicillins and none of the cephalosporins were hydrolysed. Electronic environment of allylic carboxy group in dihydrothiazine ring restricts the acceptance of cephalosporins as substrates. The efficiency of hydrolysis of penicillins is dependent on dense resonating electronic environment of phenyl ring present in the side chain, flexibility of the side chain and the distance between the phenyl ring and carbonyl group in the side chain.

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.

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.