Biochemistry - The Chemical Reactions of Living Cells, Volume 1 - D. Metzler 1980
The Setting
Simplest Living Organisms
Bacterial Nutrition
Autotrophic ("self-feeding") Bacteria synthesize all the organic components of their Cells from carbon dioxide, Water, and Inorganic Compounds of nitrogen and sulfur. For photoautotrophic bacteria, sunlight serves as the energy source, whereas chemoautotrophs rely on The energy released during the transformation of inorganic compounds. For instance, hydrogen bacteria oxidize H2 to H2O, while sulfur bacteria (inhabiting sulfur springs) oxidize H2S to H2SO4.
Most species of bacteria, much like Fungi and animals, are chemoheterotrophs in terms of their Nutrition, meaning they utilize the energy released during The breakdown of organic matter. Some heterotrophic bacteria are anaerobes, which means they decompose complex Organic compounds (such as sugars) in the complete absence of oxygen—a process known as Fermentation. Certain anaerobes oxidize organic compounds using inorganic electron acceptors, notably nitrate (denitrifying bacteria) or sulfate (sulfate-reducing bacteria). For A number of anaerobic bacteria, belonging primarily to the genus Clostridium, oxygen is toxic; these are referred to as obligate anaerobes. Others, including E. coli, are facultative anaerobes, meaning they are capable of growing both in the presence and absence of oxygen. Obligate aerobes use The oxidation of organic compounds by atmospheric oxygen as their energy source.
Class="center">Table 1-1 Outline of Modern Bacterial Classification a,b
|
Kingdom Procaryotae |
|
Subkingdom I: Cyanobacteria (botanical name: cyanophytes, blue-green Algae) |
|
Subkingdom II: Bacteria Bacteria are further divided into 19 groups; among these, certain genera are grouped into families and orders, whereas the phylogenetic relationships of others remain undetermined. The table lists individual genera, predominantly those mentioned in this book. Representatives of the same family are listed consecutively, separated by commas, and are separated from members of other families by semicolons. |
|
1. Photosynthetic (phototrophic) bacteria Rhodospirillum, Rhodopseudomonas (purple nonsulfur bacteria); Chromatium, Thiospirillum (purple sulfur bacteria); Chlorobium (green sulfur bacteria) |
|
2. Gliding bacteria Beggiatoa (filamentous bacterium containing sulfur granules) |
|
3. Sheathed bacteria |
|
4. Budding and/or appendaged bacteria |
|
5. Spirochetes (long, helical bacteria reaching up to 500 µm in length, capable of locomotion via axial filaments located between the outer sheath and The Cell body) Treponema (T. pallidum — CAUSATIVE AGENT OF Syphilis), Leptospira |
|
6. Spiral and curved bacteria Spirillum, Bdellovibrio |
|
7. Gram-negative aerobic rods and cocci Pseudomonas, Gluconobacter; Azotobacter; Rhizobium; Acetobacter; Brucella (B. abortus — causative agent of brucellosis), Halobacterium |
|
8. Gram-negative facultatively anaerobic rods Escherichia, Salmonella (S. typhi — causative agent of typhoid fever), Shigella (S. dysenteriae — causative agent of bacterial dysentery), Klebsiella, Serratia; Proteus, Yersinia (Y. pestis — causative agent of plague), Enterobacter c, Vibrio (V. cholerae — causative agent of cholera), Zymomonas; Flavobacterium, Haemophilus |
|
9. Gram-negative anaerobic bacteria Desulfovibrio, Butyrivibrio |
|
10. Gram-negative aerobic cocci and coccobacilli Neisseria (N. gonorrhoeae — causative agent of Gonorrhea) |
|
11. Gram-negative anaerobic cocci Veillonella |
|
12. Gram-negative chemolithotrophic bacteria Nitrobacter, Nitrosomonas; Thiobacillus |
|
13. Methane-producing bacteria Methanobacterium |
|
14. Gram-positive cocci Micrococcus, Staphylococcus (S. aureus — causative agent of furunculosis and inflammatory processes); Streptococcus (S. pyogenes — causative agent of scarlet fever and tonsillitis; S. pneumoniae — causative agent of Pneumonia), Leuconostoc; Peptococcus |
|
15. Endospore-forming rods and cocci Aerobes: Bacillus (B. anthracis — causative agent of anthrax) Anaerobes: Clostridium (C. tetani — causative agent of tetanus; C. botulinum — causative agent of botulism) |
|
16. Gram-positive non-spore-forming rod-shaped bacteria Lactobacillus |
|
17. Actinomycetes and related organisms Corynebacterium (C. diphtheriae — causative agent of diphtheria); Propionibacterium; Actinomyces, Bifidobacterium; Mycobacterium (M. tuberculosis — causative agent of tuberculosis); Streptomyces |
|
18. Rickettsias (parasitic bacteria with highly specialized nutritional requirements and a small Genome Size) Rickettsia (R. rickettsii — causative agent of Rocky Mountain spotted fever); Chlamydia (C. trachomatis — causative agent of trachoma) |
|
19. Mycoplasmas Mycoplasma; Acholeplasma; Thermoplasma |
a Adapted from Bergey's Manual of Determinative Bacteriology, 8th ed. Williams and Wilkins, Baltimore, Maryland, 1973.
b A number of human diseases caused by specific types of bacteria are listed.
c Formerly Aerobacter.
One of the largest groups of obligately aerobic heterotrophic bacteria is the pseudomonads (Pseudomonas and closely related genera); they are of great interest to biochemists due to their ability to oxidize organic compounds such as alkanes, aromatic Hydrocarbons, and Steroids, which are left unutilized by most other bacterial species. As a rule, any given bacterial species catalyzes only a limited range of oxidation reactions. For example, acetic acid bacteria derive all their required energy from the oxidation of ethanol to acetic acid:
CH3CH2OH + O2 → CH3COOH + H2O. (1-1)
A crucial criterion in bacterial classification is their Gram-staining behavior. Depending on their ability to retain the basic dye crystal violet applied as an iodine complex, bacteria are categorized as Gram-positive or Gram-negative. This property is determined by the architecture of their cell walls (Chapter 5). Most actinomycetes, cocci, and spore-forming rods are Gram-positive, whereas E. coli, other enteric bacteria, and pseudomonads are Gram-negative (Table 1-1).
Last update: 06/08/2026
Editorial and Educational Adaptation: This material has been compiled based on the primary/original source text. The project team performed an editorial review, corrected technical inaccuracies, structured sections, and adapted the content for an educational format.
What was processed:
- elimination of formatting defects (OCR errors, structural breaks, corrupted characters);
- editorial organization of content;
- standardization of terminology in accordance with academic sources;
- verification of factual statements against the original source text.
All mentions of the author, publication year, and origin of the primary text have been preserved in accordance with the source.