MINE-DETECTING MICROBES TO BE TESTED AT EDWARDS.

Byline: Jim Skeen Staff Writer

EDWARDS AIR FORCE BASE - Florescent microbes being developed to help the Army find land mines will get a test run at Edwards Air Force Base next month to see if they can be used in the harsh Mojave Desert.

Following the base's Oct. 21 open house and air show, the Air Force is planning to conduct a test to see if the microbes can detect residue from TNT blasts set off during the show. The test, which will cost about $200,000, will also look at how long the microbes will last in desert conditions.

``We're looking at this as a tool to cleanup inactive ranges,'' said Gary Hatch, spokesman for the base's environmental management division. ``If this works, this could be a cost effective way for us to locate where explosives are.''

Edwards has approximately 100 square miles that will require screenings for unexploded ordinance. The base is looking for a technology capable of screening large areas.

The microbe detection method is being developed by the Department of Energy's Oak Ridge National Laboratory in Tennessee. Researchers are using a common bacteria, pseudomonas putida, modified with a fluorescence gene from jellyfish, as a detection system.

The test is awaiting approval from the U.S. Environmental Protection Agency.

The microbes are sprayed on the ground and a laser light is used to measure the intensity of the fluorescence to detect possible locations of explosives. The bacteria feeds on TNT that leaks from the casings of explosives.

Oak Ridge researchers conducted a test in South Carolina where an artificial minefield was created. Researchers found there was a good correlation between the intensity of the microbes' fluorescence and mine location.

``This is a harsh environment for the microbes because they need protection from UV light and they need moisture,'' Hatch said. ``Here it's hot, dry and sunny.''

The Air Force is planning to conduct the tests in three areas - near the base control tower, an area next to the new base dormitory where there are four filled-in trenches containing unknown material, and an area near Jones Road and Lancaster Boulevard.

The area near the control tower is a spot where charges will be set off as part of a bombing run demonstration for the Oct. 21 open house and air show. The area was selected because there will be fresh TNT residue after the air show.

The Jones Road and Lancaster Boulevard site is a known ``clean'' area where there has not been any explosives used.

The trench area used to be part of a chemical weapons storage yard in the early 1940s. The area is not believed to contain any explosives, but Air Force officials are not sure what the trenches might contain. The Air Force is looking at spending $8 million to $13 million to dig the trenches up.

Each of the three areas is approximately a quarter-acre in size.

The microbes are expected to detect the TNT residue within two to four hours.