A New Type of Glucose Fermentation by Clostridium thermoaceticum
The thermophilic fermentation of cellulosic material is generally regarded -as a result of the combined action of several species of bacteria, some of which attack the cellulose and others the sugars formed from the breakdown of the cellulose. Much effort has been spent on attempts to isolate the cellulose fermenters but very little attention has been paid to the associated sugar-fermenting organisms. Snieszko and Kimball (1933) isolated and described two types of such bacteria but gave no chemical data on the fermentation products formed. It, therefore, seemed desirable to make such a study.
A RAPID METHOD FOR THE DETERMINATION OF SUGAR IN BACTERIAL CULTURES
The fermentability or non-fermentability of a given sugar is a question which must be constantly decided in the classification of bacteria. Because of the number of sugars and often the larger number of cultures involved, the bacteriologist usually resorts to indirect methods to determine his decision. Turbidity of the media, gas or acid production are the usual criteria taken to indicate fermentation. Everyone realizes that these indirect methods are uncertain and often misleading. Some bacteria produce little or no cloudiness in the media, large numbers produce such small quantities of gas that it cannot be detected except by very refined methods, and others convert most of the sugar into neutral products, such as ethyl alcohol, mannitol, acetone, etc. (Stiles, Peterson and Fred, 1925; Reilly, Hickenbottom, Henley and Thaysen, 1920). In many instances fermentations are best made with an excess of CaCO8 and in such cases gas and acid production are excluded as a means of determining fermentability. In a recent study of anaerobic bacteria Brown (1925) emphasizes the difficulty of determining the fermentability of sugars by indirect methods. A direct method of measuring the sugar destroyed is much to be preferred. It gives a definite and accurate measure of the fermentability of the sugar. Such a method to be widely used must be quick and fairly accurate. The gravimetric methods
Cuisine and Empire: Cooking in World History
List of Illustrations List of Tables Acknowledgments Introduction 1. Mastering Grain Cookery, 20,000--300 B.C.E. 2. The Barley-Wheat Cuisines of the Ancient Empires, 500 B.C.E.--400 C.E. 3. Buddhist Cuisines, 260 B.C.E.--4800 C.E. 4. Islam Transforms the Cuisines of Central and West Asia, 800--1650 C.E. 5. Christianity Transforms the Cuisines of Europe and the Americas, 100--1650 C.E. 6. Prelude to Modern Cuisines: Northern Europe, 1650--1840 7. Modern Cuisines: The Expansion of Middling Cuisines, 1810--1920 8. Modern Cuisines: The Globalization of Middling Cuisines, 1920--2000 Notes Bibliography Index