Ch. 1 — Summary: Issues and Options • 9 
• the possibility of ecological disruption, and 
• less de\ elopment in basic R&.D (and more 
speculation) than in the industries in which 
micro-organisms are used in a controlled 
enxironment. 
Ml.VEH XL LEACHING AND RECOV ERX 
Bacteria ha\ e been used to leach metals, such 
as uranium and copper, from low-grade ores. 
•Although there is reason to heliexe leaching 
ability is under genetic control in these orga- 
nisms, practically nothing is known about the 
precise mechanisms inxoKed. Iherefore, the 
application of genetic technologies in this area 
remains speculatixe. Progress has been slow in 
obtaining more information, partly because 
\ ery little research has been conducted. 
In addition to leaching, micro-organisms can 
be used to recover valuable metals or eliminate 
polluting metals from dilute solutions such as in- 
dustrial waste streams. The process makes use 
of the ability of micro-organisms to bind metals 
to their surfaces and then concentrate them in- 
ternally. 
The economic competitiveness of biological 
methods is still unproved, but genetic modifica- 
tions have been attempted only recently. The 
cost of producing the micro-organisms has been 
a major consideration. If it can be reduced, the 
approach might be useful. 
ENHA.NCED OIL RECOVERY 
Many methods have been tried in efforts to 
remove oil from the ground when natural 
e.xpulsive forces alone are no longer effective. 
Injecting chemicals into a reservoir has, in many 
cases, aided recovery by changing the oil’s flow 
characteristics. 
Micro-organisms can produce the necessary 
chemicals that help to increase flow. Theoreti- 
cally, they can also be grown in the wells 
themselves, producing those same chemicals in 
situ. The currently favored chemical, xanthan, 
is far from ideal for increasing flow. Genetic 
engineering should be able to produce chem- 
icals with more useful characteristics. 
The current research approach, funded by 
the Department of Energy (DOE) and independ- 
ently by various oil companies, is a two-phase 
process to find micro-organisms that can func- 
tion in an oil reserv oir en\ ironment, and then to 
improve their chai'acteristics genetically. 
The genetic alteration of micro-organisms to 
produce chemicals useful for enhanced oil re- 
covery has been more successful than the alter- 
ation of micro-organisms that may be used in 
situ. However, rDNA technology has not been 
ap})lied to either case. All attempts have em- 
ployed artificially induced or naturally occur- 
ring mutations. 
POLLUTION CXINTROL 
Many micro-organisms can consume various 
kinds of pollutants, changing them into relative- 
ly harmless materials before they die. These 
micro-organisms always have had a role in 
"natural” pollution control: nevertheless, cities 
have resisted adding microbes to their sewerage 
systems. Although the Environmental Protec- 
tion Agency (EPA) has not recommended addi- 
tion of bacteria to municipal sewerage systems, 
it suggests that they might be useful in smaller 
installations and for specific problems in large 
systems. In major marine spills, the bacteria, 
yeast, and fungi already present in the water 
participate in degradation. The usefulness of 
added microbes has not been demonstrated. 
Nevertheless, in 1978, the estimated market 
of biological products for pollution control was 
$2 million to S4 million/year, divided among 
some 20 companies; the potential market was 
estimated to be as much as $200 million/year. 
To date, genetically engineered strains have 
not been applied to pollution problems. Restrict- 
ing factors include the problems of liability in 
the event of health, economic, or environmental 
damage; the contention that added organisms 
are not likely to be a significant improvement; 
and the assumption that selling microbes rather 
than products or processes is not likely to be 
profitable. 
Convincing evidence that microbes could re- 
move or degrade an intractable pollutant would 
encourage their application. In the meantime, 
however, these restrictions have acted to inhibit 
the research necessary to produce marked im- 
provements. 
