Microbiology and Immunology

Biotechnology WORLD OF MICROBIOLOGY AND IMMUNOLOGY

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isms that are metabolically specific to hydrocarbons often

does not affect the overall rate of degradation.

Environmental conditions under which spill residues

occur are often sub-optimal for toxin degradation by microor-

ganisms. Most commonly the rate is limited by the availabil-

ity of oxygen or of certain nutrients such as nitrate and

phosphate. Therefore the microbial breakdown of spilled

hydrocarbons on land can be greatly enhanced by aeration and

fertilization of the soil.

Metals are common pollutants of water and land

because they are emitted by many industrial, agricultural, and

domestic sources. In some situations organisms can be utilized

to concentrate metals that are dispersed in the environment.

For example, metal-polluted waste waters can be treated by

encouraging the vigorous growth of certain types of vascular

plants. This bioremediation system, also known as phytore-

mediation, works because the growing plants accumulate high

levels of metals in their shoots, thereby reducing the concen-

tration in the water to a more tolerable range. The plants can

then be harvested to remove the metals from the system.

Many advanced sewage-treatment technologies utilize

microbial processes to oxidize organic matter associated with

fecal wastes and to decrease concentrations of soluble com-

pounds or ions of metals, pesticides, and other toxic chemi-

cals. Decreasing the aqueous concentrations of toxic

chemicals is accomplished by a combination of chemical

adsorption as well as microbial biodegradation of complex

chemicals into their inorganic constituents.

If successful, bioremediation of contaminated sites can

offer a cheaper, less environmentally damaging alternative to

traditional clean-up technologies.

See alsoEconomic uses and benefits of microorganisms;

Microbial genetics; Waste water treatment; Water purification;

Water quality

BBiotechnologyIOTECHNOLOGY

The word biotechnology was coined in 1919 by Karl Ereky to

apply to the interaction of biology with human technology.

Today, it comes to mean a broad range of technologies from

genetic engineering (recombinant DNAtechniques), to animal

breeding and industrial fermentation. Accurately, biotechnol-

ogy is defined as the integrated use of biochemistry, microbi-

ology, and engineering sciences in order to achieve

technological (industrial) application of the capabilities of

microorganisms, cultured tissue cells, and parts thereof.

The nature of biotechnology has undergone a dramatic

change in the last half century. Modern biotechnology is

An oil spill. The oil does not mix with the water.

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