Ch. 7 — The Use of Genetically Engineered Micro-Organisms in the Environment • 123 
engineering. (See ch. 10 for a moi’e detailed 
discussion of risk.) 
OE.NETIC E.\(;i\EEKI.\(; OF MICKO-OKO.AMSMS 
FOK I'SE I,\ OrilEK ASPECTS OF OIL 
RECOVER V A.M) TREATMENT 
I'wo other aspects of microhial {)hvsiolog\’ 
deserve attention: the microhial production of 
oil muds or di'ill luhricants, and the treatment 
of oil once it has been recovered. Drilling muds 
are suspensions of clays and other materials 
that serve both to lubricate the drill and to 
counterbalance the upu'aixl pressui’e of oil. Mi- 
ci'ohially pi'oduced polysaccharides have been 
dev eloped for this use. K.x.xon holtls a patent on 
a formulation based on the production of xan- 
than gum, from Xanthomonas campestris, while 
the Pillshui'v Co. has developed a [)olysac- 
charide (glucan) from various s[)ecies of Scler- 
otium. .At least two of the small genetic 
engineering firms have begun I'esearch pro- 
grams to develop biologically pi'oduced polysac- 
charides with the desired lubricant qualities. 
Interest in the postrecovei’v mici'obial treat- 
ment of oil after its extraction centers around 
the ability of micro-organisms to remove un- 
tlesirahle contituents from the crude oil itself. 
As an indication of recent progress, three dis- 
tinct microhial systems have been developed to 
help remove aromatic sulfur-containing mate- 
rial, a major impurity. 
Oi'ervieiv of genetic engineering in 
mining and oil recovery 
The underlying technical problem with the 
use of genetically engineered organisms in 
either mining or oil recovery is the magnitude 
ol the effort, in both cases, large areas of land 
and large volumes of materials (chemicals, flu- 
ids, micro-organisms) must he used. The results 
ol testing any new micro-organism in a labora- 
tory cannot automatically he extrapolated to 
large-scale applications. The change in 
magnitude is fui'ther complicated by the lack of 
rigid controls. Linlike a large fermenter whose 
temperature, pfl, and other characteristics can 
he carefully regulated, the natural environment 
cannot he controlled. Nevertheless, despite the 
formidable obstacles, the potential value of the 
products in these areas assures continuing ef- 
forts. 
Pollution control 
Life is a cycle of synthesis and degradation- 
synthesis of complex molecules from atoms and 
simple molecules and degradation by bacteria 
yeast, and fungi, back to simpler molecules and 
atoms when organisms die. The degradation of 
complex molecules is an essential part of life. 
U'ithout it, “. . . w e’d be knee-deep in dino- 
saurs.”* A more quantitative statement is equal- 
ly thought provoking. Livestock in the United 
States produce 1.7 billion tons of manure an- 
nually. Almost all of it is degraded by soil micro- 
organisms. 
For a long time people have exploited micro- 
bial life forms to degrade and detoxify human 
sewage. Now, on a smaller scale, science is 
'R. B. Grubbs, "Bacterial Supplementation, What It Can and Can- 
not Do." oral presentation to the Ninth Engineering Foundation on 
Environmental Engineering in the Food Processing Industry, 1979 
(Available from Flow Laboratories, Inc., Rock\ ille, Md.l 
beginning to use micro-organisms to deal with 
the pollution problems presented by industrial 
toxic wastes. Chemicals in their place can be 
useful and beneficial; out of place, they can be 
polluting. 
Pollution problems can be divided into two 
categories; those that have been present for a 
long time in the biosphere— e.g., most hydro- 
carbons encountered in the petroleum industry 
and human and animal wastes— and those that 
owe their origin to human inventiveness— e.g., 
certain pesticides. Chemicals of both sorts, 
through mishap, poor planning, or lack of 
knowledge at the time of their application 
sometimes appear in places where they are 
potentially or actually hazardous to human 
health or the environment. 
Pollution can he controlled hy microbes in 
two ways; hy enhancing the growth and activity 
