Natural occurrence of mycotoxins and toxigenic capacity of Alternaria strains from mouldy peppers.

Sweet pepper (Capsicum annuum) is an important crop cultivated worldwide, with Argentina being one of the major producers in South America. The fruit is susceptible to several fungal diseases, leading to severe economic losses for producers. In this study, Alternaria was found as the prevalent genus in mouldy peppers (50% fruits infected).

Toxigenic Alternaria species from Argentinean blueberries.

Blueberries are traditionally consumed in North America, some European countries and Japan. In Argentina, the blueberry crop is profitable because production starts in November, when the northern hemisphere lacks fresh fruit. Fungal contaminants can grow and produce mycotoxins in fresh fruit.

Alternaria toxins in wheat during the 2004 to 2005 Argentinean harvest.

The natural occurrence of Alternaria mycotoxins in Argentinean wheat from the zone 5 South during the 2004 to 2005 harvest was investigated in 64 wheat samples. All samples were highly contaminated with a wide range of fungal species. Alternaria was found as the main component of the mycota, with an infection percentage of 100%.

Natural occurrence of nivalenol and mycotoxigenic potential of Fusarium graminearum strains in wheat affected by head blight in Argentina.

The principal agents of Fusarium head blight in the main cropping area of Argentina were investigated in heavily infected samples. The ability of the isolates to produce trichothecenes was determined by GC and HPLC. Fusarium graminearum was the predominant species and of 33 isolates, 10 produced deoxinivalenol (DON) (0.

Mycotoxin production by Alternaria strains isolated from Argentinean wheat.

The toxigenic potential of Alternaria strains isolated from Argentinean wheat was investigated. A total of 123 strains were assayed for the production of tenuazonic acid (TA), alternariol (AOH) and alternariol monomethyl ether (AME). All but one of the isolates were able to produce at least one of the three mycotoxins.

Occurrence of alternariol, alternariol monomethyl ether and tenuazonic acid in Argentinean tomato puree.

The occurrence ofAlternaria mycotoxins was investigated in 80 samples of tomato puree processed and sold in Argentina. Alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) were searched for by liquid chromatography. Thirty-nine of the 80 samples showed mycotoxin contamination.

CRYSTALLINE HUMAN UROKINASE: SOME PROPERTIES.

Human urokinase, an enzyme which activates plasminogen, has been crystallized. Repeated recrystallization yielded preparations of maximum specific activity; such preparations revealed only one component when subjected to polyacrylamide gel disc electrophoresis. Studies with the ultracentrifuge demonstrated that urokinase undergoes a concentration-dependent reversible association at pH 6.