Abstract: Mutations are induced in a microorganism selected from the species Saccharomyces cerevisiae or from the species Candida flareri. The resulting mutants are cultured in the presence of a fermentation inhibitor, such as acetaldehyde, ephedrine or PAC-dione, to form colonies having resistance to the inhibitor. Cells from the colonies are isolated and tested for yield of phenyl acetyl carbinol (PAC) in a fermentation with benzaldehyde and pyruvate. Yeast cells from the colonies that produce elevated levels of PAC are selected for use in subsequent fermentations. PAC is useful as an intermediate in the preparation of l-ephedrine and d-pseudoephedrine, two well-known medicinal chemicals.

Abstract: Mutations are induced in a microorganism selected from the species Saccharomyces cerevisiae or from the species Candia flareri. The resulting mutants are cultured in the presence of a fermentation inhibitor, such as acetaldehyde, ephedrine or PAC-dione, to form colonies having resistance to the inhibitor. Cells from the colonies are isolated and tested for yield of phenyl acetyl carbinol (PAC) in a fermentation with benzaldehyde and pyruvate. Yeast cells from the colonies that produce elevated levels of PAC are selected for use in subsequent fermentations. PAC is useful as an intermediate in the preparation of 1-ephedrine and d-pseudoephedrine, two well-known medicinal chemicals.

Abstract: Method for transforming anaerobic microorganisms. Anaerobic microorganisms are induced to form L-forms. Genetic material capable of inducing the desired phenotype is introduced into the L-forms, after which the L-forms may be caused to regenerate their cell wall. These methods are also useful for obtaining desired biological products. Additionally, shuttle vectors capable of transforming both aerobic and anaerobic microorganisms are set forth.