uppbyggande av nya - galaktosidas producerande jaeststammar och foerfaranden foer industriellt utnyttjande av dylika jaeststammar.

摘要

This invention relates to new Saccharomyces cerevisiae yeast strains into which an -galactosidase gene (MEL) has been introduced by genetic engineering methods. Bakers' and distillers' yeasts which produce - galactosidase are applicable in the industry in these fields, where they can utilize the raffinose in molasses, resulting in increased growth of the yeast (or a greater ethanol yield) and a reduction in the waste water pollution caused by industry. The improved ability of brewers' yeast to produce -galactosidase can be used as a measure of the pasteurization of beer. Yeast strains produced by recombinant DNA techniques produce more -galactosidase than yeast strains naturally producing -galactosidase. A method for labelling of microorganism strains and a method for obtaining stable yeast transformants are also presented.