The enzymatic mechanism by which microorganisms synthesize acetoin and other ketols has been the subject of much experimentation. Many bacteria form acetoin by the intermediate formation of a-acetolactate from two moles of pyruvate, followed by decarboxylation (Dolin and Gunsalus, 1951; Discherl and Hofermann, 1951; Happold and Spencer, 1952; Juni, 1952a). Yeasts, however, utilize free aldehyde...

There is a wide range of information available on by-product disposal methods used by large national breweries. However, little information is available on the methods of by-product disposal used by craft breweries. An investigation was carried out in which 200+ British craft brewers were contacted, of which 90 craft brewers provided basic information about their brewery operations and by-produ...

The activity of yeast invertase as a function of oxidation-reduction potential has been investigated using a large number of oxidants and reductants. The activity is constant over the range of E(h) from -270 to +600 mv., but above E(h) = +600 mv. there is a sharp decrease in activity reaching 0 at E(h) = +1,000 mv. The inhibiting action of strong oxidants is upon the enzyme rather than on the s...

TRIVALENT chromium has been identified as an essential trace element in the maintenance of normal carbohydrate metabolism, both in man and in animals. Its deficiency leads to an impairment of glucose tolerance which is reversed when the diet is supplemented by chromium salts, and more rapidly by foods with a high organic content.' The absorption of chromium depends upon the chemical form in whi...

Cabib and Leloir (2) isolated and characterized guanosine diphosphate (GDP) mannose from bakers’ yeast and postulated that this nucleotide may serve as a donor of mannose residues for the synthesis of polymers which are present in the yeast cell wall. The occurrence of GDP-mannose may be ubiquitous since it has been reported to be present in hen’s oviduct (3), the molds Penicillium chrysogenum ...

A feeding trial was conducted for 75 days to study the effects of live brewer’s yeast (Saccharomyces cerevisiae) on growth and body composition in post larvae of the giant freshwater prawn, Macrobrachium rosenbergii (de Man). Five diets were formulated containing optimum protein level of 35.24±0.04. These experimental feeds were supplemented with 0.0% (control diet), 0.1%, 0.2%, 0.5% and 1.0% l...