Understanding Biotechnology

What is Biotechnology

Overview of Biotechnology

History of Biotechnology

Why do we do biotechnology?

Biotechnology for the environment

Biotechnology for food and agriculture

Huge numbers of bacteria exist naturally in soil, rubbish, recycling and land fill sites. Some slowly break down the many different types of waste, and others use oil as a source of nutrients, just as we use food. These bacteria can be used to break down oil spills at sea or on the shore.

Using biological treatment to solve waste or hazardous chemical problems is not a new idea. What is new is the greatly increased range of treatments that may be possible using biotechnology.

Biotechnologists can use the tools of gene technology to recombine, or mix and match, the most desirable traits of several bacterial species to create recombinant (genetically engineered) varieties.

For example, scientists could perhaps isolate a gene from one strain that allows it to break down some specific hazardous waste, and a gene from another strain that allows it to withstand wide temperature ranges, lack of oxygen or other environmental extremes. These genes could then be transferred into a common, harmless bacterium that can be easily mass produced.

The ideal result would be a custom-made bacteria that could clean up a specific problem waste at a particular site under defined conditions.

For a great overview about bacteria, bioremediation and links to other sites, visit the Virtual Museum of Bacteria: http://www.bacteriamuseum.org/

Read about the natural bacteria that were found to eat thiocyanate, a by-product of gold mining: http://www.csiro.au/files/mediaRelease/mr1998/PoisoneatingBugsStrikeGold.htm

Read about current research going on at the Cooperative Research Centre for Environmental Biotechnology: http://www.ebcrc.com.au/

Removing the excess

Starting at home

Do you have a compost heap at home for your food and plant scraps? Bacteria love to eat these scraps, breaking them down into compost that can be used on the garden.

Sewage treatment plants also use garbage-loving bacteria. In almost every city, raw sewage is treated in processing plants.

First, the solids are separated from the liquids and washed, dried and disposed of. Grit and sand are also removed. The liquid goes into a settling tank where most of the remaining solid material sinks to the bottom, this is called sludge.

Then, the bacteria are called in to do their job. Naturally occurring microorganisms break down the organic material and purify the liquid. They can either be encouraged to grow on stones over which the sewage is trickled, feeding on the sewage and purifying the water; or the process can be sped up using aeration tanks. Air is blown into tanks of sewage, where the suspended microorganisms feed on the waste.

The waste water is settled and sometimes given a final treatment using sand filters, reed beds or grass plots. Some sewage treatment plants also disinfect using ultraviolet light to kill bacteria.

Removing nutrients from waste water

In Australia, toxic blue–green algal blooms and red tides are responsible for millions of dollars' worth of stock losses each year. Run-off from farms and from livestock areas causes minerals and organic nutrients such as phosphorus and nitrogen to build up in rivers and lakes. This causes eutrophication; algae proliferate and quickly use up much of the dissolved oxygen in the water, killing other aquatic organisms.

Eutrophication is a well‑recognised environmental problem worldwide. To combat it, tough standards on nutrient discharge are in place. Industries are also researching biological nutrient removal (BNR) systems to treat their wastewater before discharging it into rivers.

Biological treatment is by far the cheapest and most environmentally‑friendly way of removing nutrients from wastewater. Existing methods involve microorganisms that work together to take out nutrients from the water. However, they are not reliable enough to do away with the use of chemicals altogether.

As an example, removing high levels of phosphorus from wastewater requires a large quantity of expensive chemicals. Furthermore, additional (chemical) waste sludge is generated in the process. Scientists are working on ways to use laboratory-‑grown microorganisms to remove nutrients from wastewater.

Reducing nitrogen use in sugarcane farming

Much of Australia's sugarcane is grown along coastal regions bordering the environmentally‑sensitive Great Barrier Reef and World Heritage rainforests.

Researchers at the Cooperative Research Centre for Sugar Industry Innovation through Biotechnology (CRC SIIB) are examining ways to reduce N application in sugarcane fields without reducing productivity.

Compared with other sugarcane cropping systems around the world, Australian sugarcane production uses a high level of applied N fertiliser. Some growers exceed industry recommendations for N application, in the hope of improving crop performance. Researchers are identifying traits in Australian and overseas cane varieties, and in ancestral species, that make sugarcane use N more efficiently. This should increase the sustainability of the Australian sugarcane industry.

Sheep vaccine for more wool, less burps

CSIRO researchers have been developing a vaccine that targets the rumen microbial organisms — protozoa — that reduce the flow of protein to the animal's small intestine. By reducing the protozoa population, more protein would be available to the animal for growth, meaning more wool production.

As an additional environmental benefit, the researchers think the vaccine might reduce methane-producing organisms located in or on the protozoa, thereby reducing methane emissions from belching sheep.

Removing the hazardous

Oil spill cleanup approaches include treating with chemicals, using physical barriers to contain the oil, and pumping the collected oil away from the site into storage tanks.

Some bacteria and other microorganisms in the environment can break down oil into harmless small molecules in a natural, slowly-occurring process called bioremediation. This can be sped up by:

• adding nutrients to the water in the area of the spill
  • this provides the naturally-occurring bacteria in the ocean with increased nutrients, increasing their rate of reproduction and therefore the rate of oil breakdown
• adding oil-digesting bacteria to the water in the area of a spill.

Researchers are also working to genetically engineer effective oil-digesting bacteria that are well suited to the environmental conditions of the ocean. They could be used to speed up the bioremediation process in future oil spill disasters.

Cleaning up arsenic

By adding genes to common weeds, scientists have created a new tool for cleaning up arsenic in the soil. Although very small doses of arsenic and other heavy metals are essential for good health, high levels are toxic to animals and humans.

The researchers added two bacterial genes to the commonly-used laboratory plant Arabidopsis thaliana . The first gene helps convert arsenic from soil to a form that can be 'sucked up' and stored. The second gene helps the plant detoxify heavy metals and accumulate the molecules in its leaves.

The use of plants to clean the earth is called phytoremediation. Plants are cheap and use solar power! Researchers are now using larger plants that can take up more arsenic to make the process more practical.

Land mines

Land mines are explosives laid just below the surface of the ground. They are triggered when someone steps on them, causing terrible injuries, often to innocent people farming land that used to be old battlefields.

Researchers have been genetically engineering plants that could detect explosives housed in a land mine, and then fluoresce, highlighting the presence of a land mine.

This was successfully trialled in 1999, but it has limitations and some environmental concerns. Whether or not it is successful, the trial highlights that new science and technologies can be applied to a wide variety of problems.

Get that barnacle off my boat!

Anything that is left in the sea for a while will start to become colonised with marine life. The colonisation of submerged surfaces by living organisms is called marine biofouling. A common example is barnacles attached to the hulls of ships.

Biological fouling can occur on a range of surfaces, from ship hulls to the walls of houses and the interior of water pipes. It results in increased fuel consumption, corrosion, breakdown of materials and buildings, the transport of introduced pests and many other problems worldwide. Biofouling also harbours pathogens.

The major focus of fouling and antifouling technologies has been in the marine shipping industry, where fouling is estimated to cost more than $5 billion per year.

Other than repeated cleaning of surfaces, by far the most common commercial approach to fouling control is to coat surfaces with antifouling paints that contain heavy metals (copper or tin).

The main problems with these coatings are the environmental effects of the heavy metals they release. The most commonly used paints in the marine environment for the past 30 years, tributyltin-based coatings, are in the process of being banned by the International Maritime Organization.

Copper-based paints are also banned in some parts of Europe. House paints also typically contain toxic antibacterial or antifungal compounds to inhibit microbial fouling.

Australian scientists are working to develop novel approaches to the control of unwanted biofouling and corrosion on submerged surfaces and building walls using biotechnology. These approaches are based on the incorporation of metabolically active bacteria (living paints) or enzymes into coatings. This technology can also be used to incorporate bacteria into a ‘biocement’ which inhibits fouling.

The bacteria in the paint will release natural products (enzymes) that prevent the organisms that cause fouling from adhering to the surface. Enzymes are capable of catalysing the reaction to degrade any attaching organisms or fouling species

Biomining

Scientists are now using bacteria such as Thiobacillus ferroxidans to leach copper from mine wastes, improving recovery rates and reducing operating costs. The process has also allowed extraction from low grade ores. Worldwide, 25% of all copper is produced through bioprocessing.

Bioprocessing is also used to economically extract gold from very low‑grade sulphidic gold ores, once thought to be worthless. In 2006, a species of bacteria was reported to be found living on the surface of gold grains collected in Australia. The bacteria – named R. metallidurans – can survive in the presence of dissolved gold that would kill most other bacteria. It could be very useful in discovering or producing more gold

Nuclear site cleanup

In 1999, scientists in the United States developed a new variety of microbe capable of eating waste materials at nuclear sites and rendering them less harmful.

The modified microbe, based on the radiation-resistant bacteria Deinococcus radiodurans , can dispose of the toxic heavy metals and organic chemicals commonly found at weapons production sites where normal bacteria cannot survive.