ABSTRACT
Aspergillus fumigatus produced two lipases, lipase A at 30C, lipase B at 45C. Gel electrophoresis showed the two lipases to have identical molecular weight [mr. 34, 670]. Because the two lipases biosymbesized at two different temperatures showed different retention times by high performance liquid chromatography [HPLC] and because the amino acid analysis of the two purified lipases preparations revealed that they have similar amino acid composition except for the glycine content, it was, therefore, concluded that the activity of lipases biosynthesized at different temperatures is due to different closely related enzymes
Subject(s)
LipaseABSTRACT
The aim of the present study was to get uricase [s] potentially produced by an Egyptian soil acinomycete identified as Streptomyces albogriseolus. Estimation of uricase was carried out spectrophotometrically at 293. Optimal factors affecting uricase production were : uric acid concentration, 0.1% [w/v]; yeast-extract exhibited no stimulatory effect, Agitation at 200 r.p.m. increased the yield within 48 hr. which is the optimum incubation period; inoculum size, 2 ml; phosphate buffer [pH 7.0], 0.04 M; incubation temperature, 30§C; maximum uricase yield is not a function of cell growth; addition of nicotinic acid, folic acid and riboflavin exerted an obvious inhibitory effect while ascorbic acid, thiamine and pyridoxin exerted a little stimulatory effect; glucose concentration, 3% [w/v]. Studying factors affecting the activity of the crude uricase preparation resulted in the following optimal values: borate buffer, pH 9.0; uric acid concentration, 10 and micro g/ml; Optimum temperature, 30§C; incubation time of the reaction mixture, 30 min. A suggestion for the present uricase production under pilot scale fermentation was introduced and the possible application of the enzyme in uric acid serum determination was also indicated