206 • Technologies To Maintain Biological Diversity 



iox 8-A.— The Importance of Microbial Diversity 



Micro-organisms are important to humans 

 both for the benefits they provide and for their 

 harmful effects (7,14,19,26). Micro-organisms are 

 essential parts of the environment, contributing 

 to the maintenance of stable ecosystems. Medicine, 

 agriculture, and industry all benefit significantly 

 from products derived from micro-organisms. 



Studies of microbial ecology can provide basic 

 information about the environment (25). Microbial 

 communities provide unique model systems for 

 the study of ecological principles and the orga- 

 nization of natural populations. Because micro- 

 bial communities can occupy little space and 

 grow rapidly, it can be easier to study the princi- 

 ples of community structure and relationships 

 with such materials than with more complex eco- 

 systems that include plants and animals. 



Monitoring of environmental disturbances from 

 pollution or natural causes can be improved by 

 study of micro-organisms in the environment. 

 Species of all types are subject to extinction when 

 the environments in which they live are de- 

 stroyed. Such loss is generally preceded by more 

 subtle changes in the environment (e.g., pollu- 

 tion or nutrient loss) that can be detected far 

 earlier in the microbial population. Changes in 

 the microbial composition of ecosystems can 

 thus warn of impending environmental destruc- 

 tion resulting from pollution or other environ- 

 mental disturbance. Micro-organisms can even 

 improve water quality by degrading environ- 

 mental pollutants and naturally occurring or- 

 ganic matter. Development of new strains of 

 micro-organisms promises to provide important 

 weapons for combating pollution. 



World health has been assaulted by micro- 

 organisms, aided when they are found to be the 

 specific agents of disease, and improved through 

 development of vaccines, antibiotics, and chem- 

 ical agents to combat these organisms. Bacteria 

 from the swamps of southern New Jersey, for ex- 

 ample, led to development of a drug that has 

 proven effective against many drug-resistant and 

 hospital-acquired infections (20). The potentials 

 of micro-organisms to aid in the treatment of hu- 

 man disease are still largely unexploited or un- 

 recognized, however. 



Farming, too, has benefited from a better un- 

 derstanding of the fungal and bacterial organisms 

 associated with crops. Studies in both developed 

 and developing countries seek to improve the 

 availabihty of nitrogen to crops through the 

 nitrogen-fixation activities of various micro- 

 organisms. At present, no crop is able to obtain 

 nitrogen until it is converted into a biologically 

 useful form by industrial processes or the action 

 of micro-organisms. The U.S. corn crop alone re- 

 quires $1 billion per year in industrially produced 

 fertilizers (6). Soil fungi have been found to colo- 

 nize plant roots and greatly improve nutrient 

 availability and augment the functioning of the 

 plant's own root system (6). Micro-organisms, 

 such as the Bacillus tburingiensis commonly 

 used to combat caterpillar infestations, also have 

 been developed as biological control agents for 

 pests of agricultural crops (23). 



The industrial applications of micro-organisms 

 are numerous. Microbial fermentation provides 

 a large number of the foods, beverages, and 

 chemicals that are a part of modern society (13). 

 Butyric acid-producing bacteria have been used 

 for centuries for the retting of flax and hemp. The 

 same bacteria also have been applied to produc- 

 tion of the important industrial chemicals ace- 

 tone and butanol. Micro-organisms have been 

 used as biological catalysts to perform what 

 might otherwise be complex chemical conver- 

 sions in the production of a variety of medical 

 and industrial products (8,13). Microbially pro- 

 duced polysaccharides, such as xanthan gum, are 

 used to thicken, suspend, bind, lubricate, or stabi- 

 lize materials in numerous food, industrial, and 

 oil field applications (3). 



Finally, micro-organisms are a focus of re- 

 newed research interest because of technologi- 

 cal advances that allow them to be modified with 

 recombinant DNA technologies (19,30). In the 

 field of genetic engineering, micro-organisms are 

 essential, because the production of recombinant 

 nucleic acids, whether destined for use in plants, 

 animals, or micro-organisms, is accomplished in 

 bacteria or other single-celled micro-organisms 

 (6,19,30,31). 



