In accordance with the invention there is provided a method for identifying or testing an anaerobic microorganism wherein an aqueous suspension of a culture of the microorganism having a culture density of about 2.times.10.sup.8 cells/ml, is brought into contact with an aqueous solution containing an oxidation-reduction indicator which substantially irreversibly undergoes a change in color upon being reduced and a biodegradable test substrate compound which, when catabolized by a microorganism, will engender reduction of the indicator, said aqueous suspension containing nutrient in a concentration sufficient to support microorganism culture growth without engendering reduction of the indicator when said suspension contacts said solution, and said suspension also containing a compound which reduces O.sub.2 but does not reduce the indicator.
This patent application is a continuation-in-part of United States patent application Ser. No. 773,879 filed Mar. 3, 1977, now U.S. Pat. No. 4,129,483.
A test set comprising a purified culture of Streptococcus thermophilus T101 concentrate and a water-based protective agent in dilution ratio of about 4 to 5.times.10.sup.-2. The test set may also advantageously comprise an indicator. The test method includes the steps of incubating the test set and evaluating the color. The present invention also comprises a purified culture of Streptococcus thermophilus T101 strain.
Microorganisms and unicellular organisms in a sample are identified or determined by exposing the sample to an adsorbent having a specific binding power for the entity to be determined to bind the entity to the adsorbent, separating unbound sample, exposing the adsorbent containing the entity to a nutrient medium to initiate metabolism with resulting change in the physical or chemical characteristics of the substrate and observing these changes.
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.
