Protecting the Land

Protecting Our Farmland

Biopesticides

One strain of bacteria, for example, Bacillus thuringiensis (B.t.), produces a protein that is naturally toxic to certain insects. Scientists have extracted the B.t. gene that expresses the insecticide and inserted it into common bacteria that can be "grown" in large quantities by the same fermentation techniques used to produce such everyday products as beer and antibiotics. Spread on cotton and other crops, these harmless bacteria control insects naturally.

A refinement of this technology even eliminates the bacteria. The insecticidal substance itself is extracted from the bacteria, encapsulated, and used to protect a range of crops. No chemicals, no bacteria, no insect damage.

Spiders, too, provide the gene for a natural insecticide. The spider's venom-producing gene has been transplanted into a virus that infects certain crop-destroying caterpillars. When the caterpillar swallows the virus and becomes infected, the infected cells poison themselves and the caterpillar. Both the virus and the spider gene are harmless to plants and animals.

Insect Virus Products, or IVPs, are still another environmentally beneficial innovation made possible by biotechnology. IVPs were discovered in nature almost 200 years ago, but only now, using the techniques of biotechnology, can they be produced economically. All IVPs are non-toxic to people, animals, and other beneficial insects. In fact, each specific IVP affects only one type of insect. Yet over 1,600 different insects - many of them important agricultural pests - are known to be susceptible to IVPs.

As more insect-specific biopesticides emerge from this developing technology, farmers will be able to treat only the particular insects damaging their fields, and only when those insects are actually present. And it can be done without applying broad-spectrum chemicals.

Cleaning Up Wastes

Everything under the sun degrades, or breaks down, into different materials. Fallen leaves become compost, iron rusts, milk turns sour, and food 'goes bad.' Just as light, heat, and moisture can degrade many materials, biotechnology relies on naturally occurring, living bacteria to perform a similar function. Some bacteria naturally 'feed' on chemicals and other wastes, including some hazardous materials. They consume those materials, digest them, and excrete harmless substances in their place.

For decades now, municipalities have used biological methods to treat their sewage, and industry has used secondary aerobic treatment to remove harmful materials from liquid wastes. Biological treatment is not a new idea. What is new is the expanded range of biotreatment capabilities offered by the science of biotechnology.

Bioremediation uses natural as well as recombinant microorganisms to break down toxic and hazardous substances already present in the environment. Biotreatment is a broader term, which refers to all biological treatment processes, including bioremediation. Biotreatment can be used to detoxify process waste streams at the source - before they contaminate the environment - rather than at the point of disposal. This approach involves carefully selecting organisms, known as biocatalysts, which are enzymes that degrade specific compounds, and define the conditions that accelerate the degradation process.

Living Off a Landfill

Scientists today can examine a landfill and determine not only what bacteria are degrading which materials in it - including any hazardous materials - but which do it fastest, most completely, and under what optimum conditions.

Armed with this knowledge, they can clone the most efficient strains of naturally occurring bacteria, reproduce them in quantity, and apply them to the site. In effect, they can create a customized army of waste eaters.

Oil for Dinner

Following the major oil spill in Alaska's Prince William Sound, the Environmental Protection Agency brought in natural oil-eating bacteria to help clean up the mess. Follow-up studies suggest that the microbes did as good a job in cleaning up soiled beaches as high-pressure hoses and detergents could have done. "It was almost as if we had brought in fresh rock," stated the EPA's project manager after visiting the site.

Such bioremediation cannot only help to clean up oil spills, but also chlorinated chemicals and leaks from storage tanks.

Custom-Made Microbes

Biotechnologists using recombinant DNA technology - the principal tool of genetic engineering - can recombine, or mix-and-match, the most desirable traits of several bacterial species. They can, for instance, extract the gene from one strain that allows it to 'feed' on PCBs or other hazardous wastes, then take the genes that allow another bacterial strain to withstand wide temperature ranges - lack of oxygen or other environmental extremes - and transplant them into a common, harmless bacterium that can be mass produced easily. The result is an organism custom-made to 'eat up' a specific problem waste at a specific site under specific conditions.

This technology holds the potential to solve many environmental problems from the past, and leave our children an environment cleaner than we inherited from our parents.

Pollution Prevention

Special bacteria in a bioreactor can virtually eliminate methylene chloride from industrial waste water. They reduce concentrations from over 1,000,000 parts per billion to less than 5 parts per billion - far below the EPA's permissible guidelines. The bacteria in the bioreactor consume the chemical and convert it to water, carbon dioxide, and salt. They permanently destroy the hazardous material and eliminate any need to recover it, transfer it, or dispose of it.

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