Strain metabolic differences

The factors regulating the production of acids are unknown. Different yeast strains produce different amounts, and vitamin deficiencies increase the excretion of some organic acids e.g. thiamine deficiency leads to increased pyruvate levels. Many oxo-acids are produced as the result of amino acid metabolism (see below) therefore, the wort amino acid content is important. 

Figure 9.15 Commercial yeast strains possess different abilities to form and modulate compounds that affect wine sensory properties. These compounds are produced as a result of yeast metabolic processes.

Qualitatively, the metabolic degradation of drugs is similar in man and animals. Despite some exceptions, Williams [3] concluded that the main difference between man and laboratory animals probably lies in the rates of drug transformation. Koppanyi and Avery [6] have stated Strains and different species, including Homo, may differ in the rate of turnover and metabolic degradation of drugs. These differences can be measured by the methods of essential elimination, as well as by chemical or biochemical techniques. Such studies may permit a limited extrapolation from experiments on lower animals to drug effects in the human species. ... 

DNA/DNA hybridization is also an excellent tool for identifying strains that differ in phenotype but belong to the same species. The difference rests on a metabolic function which depends on the presence of one or more enzymes and therefore the presence of the corresponding genes. In this case, the probe is prepared from a DNA fragment representing all or part of the gene. 

---