Yeast tests

It is generally, but not universally, agreed that fungal test systems cure less sensitive than bacterial test systems in almost all cases, a higher dose of the agent being tested is required to elicit a response in the fungal systems. Yeast tests cure the fastest and least expensive eukaryotic assays. 

Sulfur dioxide produced weak increases in micronuclei after activation in a plant assay Tradescantia spp.). Mammalian (cow, ewe) oocytes exposed in vitro had higher levels of chromosome aberrations when exposed to SO2 without metabolic activation. The Saccharomyces cerevisae yeast test for gene mutations was also positive without activation. 

As a large number of biopharmaceuticals are administered via the intravasal route, it should again be emphasized that the established standard tests of pyrogens, endotoxins and general sterility (i.e., bacteria, fungi, yeast) testing also applies to these products, and must be incorporated into specifications and testing standards. 

These simulations suggest an additional test for the structured model that is, to compare its predictions to data on release of site-linked enzymes in yeast. Tests for cytoplasmic and mitochondrial enzyme release will be aided by preparation of a low-protease lytic system. 

Formic Acid. Hohl and Joslyn (1941a) concluded that formic acid was not a final by-product of alcoholic fermentation of sugar by the strains of yeast tested by them. The indications from their data are that little would be formed at the high pH of California grape juice and that utilization during fermentation was greater than formation. 

In contrast, almost all the yeasts tested showed reduction of carvone, although the enzyme activity varied. The reduction of (-)-carvone (93 ) was often much faster than the reduction of (+)-carvone (93). Some yeasts only reduced the carbon-carbon double bond to yield the dihydrocar vone isomers (101a and b and 101a and b) with the stereochemistry at C-1 with / -con guration, while others also reduced the ketone to give the dihydrocarveols with the stereochemistry at C-2 always... 

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