Bioconversion of poultry wastes I-factors influencing the assay and productivity of crude uricase by three uricolytic filamentous fungi.

The optimum temperature for biomass yield and uricase production by uricolytic fungi, Aspergillus terreus. A. flavus and Trichoderma sp. was at 30 degrees C. The time required for maximum production of uricase and biomass yield was 4 days for two Aspergillus species and 6 days for Trichoderma sp. The optimum pH was at 6.4 for A. terreus and pH 6.6 for both A. flavus and Trichoderma sp. The maximum fungal biomass yield was achieved in medium supplemented with 4% poultry waste. The best carbon sources for the production of uricase and mycelia yield were glycerol, sucrose and maltose by A. terreus, A. flavus and Trichoderma sp., respectively. Uric acid was found to be the best nitrogen source for production and activity of uricase by the three tested fungi. The addition of some vitamins to the culture media increased the maximum biomass yield of all the isolates, but did not significantly increase uricase production.

Bioconversion of poultry wastes. I--Factors influencing the assay and productivity of crude uricase by three uricolytic filamentous fungi.

The optimum temperature for biomass yield and uricase production by uricolytic fungi, Aspergillus terreus, A. flavus and Trichoderma sp. was at 30 degrees C. The time required for maximum production of uricase and biomass yield was 4 days for two Aspergillus species and 6 days for Trichoderma sp. The optimum pH was at 6.4 for A. terreus and pH 6.6 for A. flavus and Trichoderma sp. The maximum fungal biomass yield was achieved in medium supplemented with 4% poultry waste. The best carbon sources for the production of uricase and mycelia yield were glycerol, sucrose and maltose by A. terreus, A. flavus and Trichoderma sp., respectively. Uric acid was found to be the best nitrogen source for production and activity of uricase by the three tested fungi. The addition of some vitamins to the culture media increased the maximum biomass yield of all the isolates, although no significantly increased uricase production was found.

Liver peroxisomal fatty acid oxidizing system during aging in control and clofibrate-treated mice.

We have previously described an aging-related decrease in the peroxisomal polyunsaturated fatty acid oxidizing system in mouse liver. In order to determine whether peroxisome synthesis is involved in this phenomenon, we focused our work on different peroxisomal enzyme activities during aging in the liver of mice fed for 5 days with either a control or a clofibrate supplemented diet which enhanced peroxisome biogenesis. Liver peroxisomal acyl-CoA oxidase (AOX), catalase (CAT) and urate oxidase (UOX) activities per gram of liver were determined. In control mice, UOX activity was not affected by aging whereas CAT and AOX activities were significantly decreased. At day 300 the clofibrate treatment increased all activities although UOX was not significantly increased. Thereafter, enzyme activities after clofibrate treatment were severely depressed at day 680. CAT and UOX were not induced in very old clofibrate-treated animals, whereas AOX was induced 7 fold in such mice compared to an 11 fold induction in day 300 animals. The present results suggest that: 1- Aging decreased the peroxisomal polyunsaturated fatty acid oxidizing system. 2- This took place via a specific decrease in AOX activity. 3- Since clofibrate treatment triggers the peroxisomal proliferation, the aging-related decrease in peroxisomal activities might be due to an alteration in peroxisome synthesis.

[Different effects of homeopathic potencies and conventional dilutions on specific liver enzymes of rats--an in vivo study]. / Unterschiedliche Wirkungen von homöopathischen Potenzen und konventionellen Verdünnungen auf spezifische Leberenzyme der Ratte--ein in vivo Versuch.

It was searched for differing effects of homeopathic potencies and equally concentrated conventional dilutions. Activities of enzymes from three different subcellular compartments of the rat liver served as parameters for the evaluation. Especially in the D15/10(-15) range differences proved to be statistically relevant. The series with potentiated carrier substance, necessary from heuristic reasons and related to the homeopathic potencies, resulted in hitherto not understandable findings.

Electron cytochemical studies of Cryptococcus neoformans grown on uric acid and related sources of nitrogen.

Cells of Cryptococcus neoformans grown on xanthine or urate as the sole sources of nitrogen produced numerous, single membrane-bound organelles, deemed to be microbodies. Electron images of these structures showed positive cytochemical staining for catalase and alpha-hydroxy acid oxidase, known marker enzyme activities for microbodies. Microbodies in xanthine and urate-grown cells were cytochemically reactive for the presence of the hydrogen peroxide-producing xanthine and urate oxidases. Molybdenum and phosphorus (elements associated with the cofactor common to nitrogen scavenging enzymes) were detected in the substrate-induced microbodies by X-ray dispersive microanalysis. The single limiting membrane of the substrate-induced microbody was stained by a modified Gomori reaction for the presence of alkaline phosphatase, thereby suggesting the participation of this enzymic activity in the events associated with microbody chemistry.

Ultrastructural localization of urate oxidase in nodules of Sesbania exaltata, Glycine max, and Medicago sativa.

The localization of urate oxidase (=uricase, E.C. 1.7.3.3) was determined cytochemically in nodules of Sesbania exaltata (Raf.) Cory, soybean (Glycine max [L.] Merr.) and alfalfa (Medicago sativa [L.] ), using the precipitation of peroxide (produced during the oxidation of urate) by cerium chloride. Cerium perhydroxide reaction product was noted only in the microbodies, a localization consistent with biochemical fractionation studies on urate oxidase. Urate oxidase was present not only in the uninfected cells of the cortical tissue, but also in both infected and interstitial cells in the central tissue, suggesting that at least this enzyme of ureide metabolism is not confined to interstitial cells. Urate oxidase cytochemistry of nodules from alfalfa (Medicago sativa L.), an amide producer, also resulted in microbody staining but the microbodies were infrequently noted in cell profiles.