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The present investigation deals with purification and thermal characterization of an acid invertase produced by Fusarium solani in submerged culture. The maximum enzyme activity (9.90 U mL(-1)) was achieved after 96 h of cultivation at pH 5.0 and 30 degrees C in a basal medium containing molasses (2%) as the carbon and energy source supplemented with 1% peptone. Invertase was purified by ammonium sulfate fractionation and column chromatography on DEAE-cellulose and Sephadex G-200. The purified enzyme was proven to be homogeneous by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The molecular mass of the enzyme was 65 kDa. The optimum pH and temperature for activity were 2.6 and 50 degrees C, respectively. The Km value for sucrose was 3.57 mM with an activation energy of 4.056 kJ mol(-1). Enthalpies of activation (DeltaH) were decreased while entropies (DeltaS) of activation increased at higher temperatures. The effects of alpha-chymotrypsin and 4 M urea were tetraphasic with periodic gain and loss of enzyme activity. A possible explanation for the thermal inactivation of invertase at higher temperatures is also discussed.

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A natural dye is extracted from turmeric and used to dye cotton at different dyeing conditions. Then the fastness properties of the dyeings with different dyeing techniques are compared. The dye is found to have good saturation and rubbing fastness, but poor washing and light fastness properties on cotton, when applied without any mordant. When dyeing is implemented with mordants, washing and light fastness properties show improvement while rubbing fastness exhibits deterioration. Finally, comparative studies between natural and synthetic reactive dyes reveal that the natural dye has the potential to act as a co-partner with reactive dyes with a few compromises.

Pharmacokinetics and urinary excretion of sulphadimidine were investigated in sheep during summer and winter seasons. Average minimum and maximum environmental temperature in the summer ranged from 22.6 to 40.2 degrees C and in winter from 4.5 to 21.1 degrees C. The determination of plasma volume, plasma protein and packed cell volume during summer and winter revealed a significant decrease in plasma volume and a significant increase in plasma protein in the summer indicative of haemoconcentration. Packed cell volume did not differ significantly between the seasons. The pharmacokinetics of sulphadimidine were determined following a single intravenous injection (100 mg/kg) in summer and winter. Zero time plasma concentration of the drug was higher during summer than in winter. The elimination half-life of the drug was similar in summer and winter, but the apparent volume of distribution was lower in summer. Likewise, total body clearance was significantly lower in summer. Based on these studies a satisfactory intravenous dosage regimen might consist of 86 and 100 mg/kg for priming and 78 and 88 mg/kg as maintenance doses during summer and winter, respectively, the doses being repeated at 12 hour intervals. Twenty four hours after sulphadimidine administration 90 and 73 per cent of the dose was excreted in urine during summer and winter, respectively. The drug was excreted mainly as free amine.