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FURTHER OBSERVATIONS ON YEAST MUTATION DURING CONTINUOUS FERMENTATION
Author(s) -
Thorne R. S. W.
Publication year - 1970
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.1970.tb03342.x
Subject(s) - yeast , fermentation , mutant , strain (injury) , biology , diacetyl , saccharomyces cerevisiae , food science , genetics , gene , anatomy
It has been known for some time that conditions prevailing during continuous cultivation of micro‐organisms favour the accumulation of mutant forms, a circumstance that is relevant to the stability of yeast behaviour and of beer quality during continuous fermentation. In an earlier paper the writer reported an investigation of the types of mutant appearing over an extended period of continuous cultivation of a particular strain of flocculent bottom fermenting brewery yeast: loss of flocculence and reduction of fermentation efficiency were the most commonly encountered mutations. Since nothing could be inferred as to the general validity of these results it was thought desirable to repeat the investigation with another strain of a similar type of yeast. While the occurrence of mutants was even more conspicuous than before, the overall picture was in some ways quite different: this strain appears to be less mutable in respect of flocculence, but more so in respect of growth rate, maltotriose fermentability and diacetyl production. The evidence so far available thus suggests that yeast strains are idiosyncratic as regards their mutational tendencies.