Aspergillus terreus and its toxic metabolites as a food contaminant in some Egyptian Bakery products and grains

A. terreus isolates isolated from some bakery products, corn and rice were found to be able to produce territrems. 90% of theA. terreus isolated from bakery products were able to produce territrem A, with a mean of 0.09 ppm, while 80% ofA. terreus isolates produce territrem B with a mean of 0.24 ppm. On the other hand 31.8% of the isolates ofA. terreus from corn were able to produce territrem A with a mean of 0.44 ppm. ConcerningA. terreus isolates from rice, 66.7% were found to produce territrem A, with a mean of 5.28 ppm, and 77.8% of the isolates produced territrem B with a mean of 1.79 ppm.     

DNA associated with nucleosomes in plants.

50 to 55% of tobacco and barley nuclear DNA is accessible to micrococcal endonuclease digestion. The DNA fragments resulting from a mild endonuclease treatment are multiples of a basic unit of 194 +/- 6 base pairs in tobacco and 195 +/- 6 base pairs in barley. After extensive digestion, a DNA fragment of approximately 140 base pairs is predominant. Hence the "extra-core" or "linker"-DNA is 55 base pairs long. Other fragments having 158 and less than 140 base pairs are present as well. Treatment with DNase I results in multiples of 10 bases when analysed under denaturating conditions. These results show that the general organization of the DNA within the nucleosomes is about the same in higher plants as in other higher eukaryotes.     

Degradation of insulin-like growth factors in small intestine of suckling rats

Insulin-like growth factors (IFGs), IGF-I and IGF-II, present in mammalian milk, play an important role during gastrointestinal tract development. In this study we identified and localized the activities of the common intestinal proteolytic enzymes and investigated their degradation effect on IGFs. Results indicated that the enzymatic activities of chymotrypsin, trypsin, and elastase progressed from the lowest in the duodenum, to the highest in the midjejunum, and declined in the ileum. Chymotrypsin exhibited the greatest IGFs degradation activities in neonatal intestinal lumen followed by elastase. These data furnish a potential strategic design to supplement IGFs into milk formulas.     

Characterization of a Novel Picornavirus Isolate from a Diseased European Eel (Anguilla anguilla)

A novel picornavirus was isolated from specimens of a diseased European eel (Anguilla anguilla). This virus induced a cytopathic effect in eel embryonic kidney cells and high mortality in a controlled transmission study using elvers. Eel picornavirus has a genome of 7,496 nucleotides that encodes a polyprotein of 2,259 amino acids. It has a typical picornavirus genome layout, but its low similarity to known viral proteins suggests a novel species in the family Picornaviridae.     

No evidence for learned mating discrimination in male Drosophila pseudoobscura

Background  

Since females often pay a higher cost for heterospecific matings, mate discrimination and species recognition are driven primarily by female choice. In contrast, frequent indiscriminate matings are hypothesized to maximize male fitness. However, recent studies show that previously indiscriminate males (e.g., Drosophila melanogaster and Poecilia reticulata) can learn to avoid heterospecific courtship. This ability of males to discriminate against heterospecific courtship may be advantageous in populations where two species co-occur if courtship or mating is costly.     

Purification and characterization of phosphodiesterase from Crotalus venom.

A procedure for the purification of phosphodiesterase from Crotalus venom on DEAE-cellulose at alkaline pH is described. The enzyme gives a single band in polyacrylamide gels and is free of contaminating nucleolytic enzymes. The molecular weight is about 115000. Concentration in an Amicon ultrafiltrator gave a highly concentrated active enzyme. Phosphodiesterase is relatively stable and can be stored at 4 degrees C in the presence of Mg2 and serum albumin for years. For the detection of contaminating endonuclease, an assay was used in which tRNA was the substrate and possible internal breaks were detected in polyacrylamide gel after denaturation. With bis(p-nitrophenyl) phosphate as substrate, 15mM Mg2 was necessary for optimal activity. The reaction remained linear for at least 15 min at 22 degrees C. At 45 degrees C, the liberation of p-nitrophenol was highest within 25 min of incubation. At 75 degrees C, inactivation of the enzyme occurred after 4 min.