General Microbiology - Schlegel, H. 1987

The role of microorganisms in nature
Microorganisms in the service of humanity

Those unversed in microbiology primarily perceive the Practical significance of microorganisms through the harm they inflict on humans, animals, and plants. These disease-causing (pathogenic) microorganisms and their specific characteristics are the focus of such sciences as medical and veterinary microbiology, as well as phytopathology. Although microorganisms sometimes act as pests in other natural spheres and in industry, their role as beneficial organisms vastly predominates. They have long secured a firm place in household Applications and are absolutely essential in industry. They are utilized across A wide variety of sectors—ranging from the primary Processing of agricultural products to catalyzing the most complex stages of chemical syntheses.

Classic microbiological industries. Using the Examples of brewing and winemaking with Yeasts, bread baking and dairy production using lactic acid Bacteria, as well as The production of edible vinegar involving acetic acid bacteria, it becomes evident that microorganisms rank among the oldest cultivated 'crops'. In Japan and Indonesia, soybeans have long been processed using filamentous Fungi, yeasts, and lactic acid bacteria. Aside from ethanol production, microorganisms only began to be utilized in the industrial manufacture of individual chemical substances over the past sixty years. Glycerol was already being produced During the first World War through controlled Yeast Fermentation. Lactic and citric acids, required in large quantities by the food industry, are produced using lactic acid bacteria and the fungus Aspergillus niger, respectively. From cheap, carbohydrate-rich waste Materials, fermentation carried out by clostridia and bacilli can yield acetone, butanol, 2-propanol, butanediol, and other important chemical compounds.

Antibiotic production. The advent of Antibiotics ushered in a new era in medicine and the pharmaceutical industry. Through the discovery of penicillin and other metabolic products of fungi, actinomycetes, and other microorganisms, humanity acquired highly effective weapons to combat bacterial infections. The search for new antibiotics continues successfully. From a theoretical standpoint, the application of antibiotics to combat viral diseases and tumors of viral origin also appears promising.

New microbial industries. Classic fermentation processes are being complemented by novel applications of microbes in chemical manufacturing. Carotenoids and Steroids are obtained from fungi. Once it was discovered that Corynebacterium glutamicum synthesizes glutamic acid in high yields from sugar and ammonium salts, mutants were isolated and Methods were developed enabling the large-scale production of many Amino Acids, NUCLEOTIDES, and biochemical research Reagents. Microorganisms are employed by chemists as catalysts to carry out specific steps in long chains of synthetic reactions; microbiological processes surpass Chemical Reactions in their chemical Specificity and product yield. Industrial Enzymes—such as amylases for starch Hydrolysis, proteinases for leather processing, pectinases for fruit juice clarification, and others—are obtained from microbial cultures.

The monopoly of microorganisms. It should be noted that certain raw materials available in exceptionally large quantities, such as petroleum, natural gas, or Cellulose, can be utilized by microorganisms and converted into cellular material (biomass) or into metabolic intermediates secreted by the Cells. Microorganisms are thus indispensable for 'upgrading' these unconventional raw materials for biotechnological processes; the exploitation of such substrates through biological technologies has only just begun.

Modern achievements in Introduction/32.html">Genetic Engineering. The Study of Gene transfer mechanisms in bacteria and the involvement of extrachromosomal elements in this process has opened up the possibility of introducing foreign DNA into bacterial cells. Genetic manipulations make it possible to insert small segments of genetic material from higher organisms, such as humans, into bacteria and prompt them to synthesize the corresponding Proteins. The production of Hormones, Antigens, Antibodies, and other proteins using bacteria is entirely feasible. Attempts are also underway to confer nitrogen-fixing ability upon plants and to treat DISEASES ASSOCIATED WITH biochemical defects.

The direct applicability of fundamental scientific knowledge. Attempting to list in this section all types of technology and products of industrial microbiology, along with other hitherto only prospective fields of application, would lead us too far astray. The connection between fundamental research and practice in microbiology, as in all natural sciences, is very tight: 'There are no applied sciences... but there are applications of science' (L. Pasteur) ['Il n’y a pas des sciences appliquées... Mais il y a des applications de la science' (Pasteur)].