Bacterial Physiology and Metabolism

J. R. Sokatch

• Publisher: Academic Press
• Year: 2014
• ISBN:
  9781483261386
• Topic: Sciences biologiques
• Subtopic: Physiologie

Bacterial Physiology and Metabolism focuses on research on bacteria, as well as metabolism of carbohydrates, fermentation, and oxidation of acids. The book first offers information on nutrition and growth of bacterial cultures, including requirements for growth, nutritional classification of bacteria, measurement of bacterial growth, and synchronous growth of bacterial cultures. The manuscript then considers the chemical composition of bacteria, oligosaccharide catabolism, and transport of sugars. The publication takes a look at the fermentation of sugars and aerobic metabolism of carbohydrates. Discussions focus on Embden-Meyerhof fermentations, miscellaneous pathways, and hexose, pentose, polyol, and hexuronic acid oxidation. The text also elaborates on oxidation of organic acids, electron transport, oxidation of hydrocarbons, and protein and amino acid catabolism. The text is a dependable reference for readers interested in bacterial physiology and metabolism.

Part One

BACTERIAL PHYSIOLOGY

Outline

Chapter 1: NUTRITION

Chapter 2: GROWTH OF BACTERIAL CULTURES

Chapter 3: CHEMICAL COMPOSITION OF BACTERIA

1

NUTRITION

Publisher Summary

This chapter discusses the requirements of certain essential nutrients in the medium or diet for growth both in bacteria and all other living organisms. Growth is understood to mean balanced growth, that is, a uniform increase in protoplasm as opposed to an increase in one or a few components. Essential nutrients fall into two classes: (1) those required to supply energy for growth and (2) those required to supply the chemical elements needed for biosynthesis. Of the various forms of energy available, bacteria can use chemical and light energy for growth. Most true bacteria use organic compounds for chemical energy but many soil bacteria are able to produce useable energy by the oxidation of inorganic chemicals. In contrast to the relatively uniform nutritional requirements of plants and animals, bacteria exhibit characteristic differences in their requirements for energy and carbon sources. A study of the distribution of nutritional types in nature suggests that this might be response to environment, for example, all autotrophic bacteria are soil and water species. The chapter also presents a classification of organisms on the basis of energy requirement and on the basis of carbon source for biosyntheses.

I Requirements for Growth

Bacteria as well as all other living organisms require certain essential nutrients in the medium or diet in order to be able to grow. Growth is understood to mean balanced growth, that is, a uniform increase in protoplasm, as opposed to an increase in one or a few components. Essential nutrients fall into two classes, those required to supply energy for growth and those required to supply the chemical elements needed for biosynthesis. Of the various forms of energy available, bacteria can use chemical and light energy for growth. Most true bacteria use organic compounds for chemical energy, but many soil bacteria are able to produce useable energy by the oxidation of inorganic chemicals. Quantitatively, the most important elements required for biosynthesis are those found in protein, namely C, H, O, N and S. These elements may suffice in their inorganic forms or may be required in the form of organic growth factors. Many other elements are required for growth, such as Mg, K, PO₄, Fe, Cu, Co, Mn and Zn, and these are also used as inorganic salts.

II Nutritional Classification of Bacteria

In contrast to the relatively uniform nutritional requirements of plants and animals, bacteria exhibit characteristic differences in their requirements for energy and carbon sources. A study of the distribution of nutritional types in nature suggests that this might be response to environment; for example, all autotrophic bacteria are soil and water species. A system of classification of nutritional types of organisms which was proposed by a group of prominent microbiologists (Lwoff et al., 1946) forms the basis of the following discussion. Organisms were classified on the basis of energy requirement and on the basis of carbon source for biosyntheses.

Developments in microbiology since 1946 have resulted in changes in the original system of classification. For example, the terms photolithotroph and photoorganotroph are not used here as the organisms formerly grouped in these categories differ in their method of assimilation of carbon (a biosynthetic process) during photosynthesis, but not in the process of converting light energy into chem...