124 • Impacts of Applied Genetics— Micro-Organisms, Plants, and Animals 
of microbes already present at or near the site 
of the pollution problem^ and by adding more 
(sometimes new) microbes to the pollution site. 
The first approach does not provide an oppor- 
tunity for applying genetics^ but an example will 
indicate how it functions. 
Enhancing existing microbial 
degradation activity 
Sun Oil successfully exploited indigenous 
microbes to clean up a 6,000 gal underground 
gasoline spill that threatened the water supply 
of a town in Pennsylvania. ^ ^ First, engineers 
drilled wells to the top of the water table and 
used pumps to skim gasoline from the water 
surface. About half the gasoline was removed in 
this fashion, but company calculations showed 
that dissipating the remaining gasoline would 
require about 100 years. To speedup the proc- 
ess, it was decided to encourage the growth of 
indigenous bacteria that could degrade the 
gasoline. 
Pollution-control microbes, like all organisms, 
require a number of different elements and 
compounds for growth. If the amount of any 
nutrient is limited, the microbe will not be able 
to metabolize the pollutant at the fastest rate. 
The cleanup depended on increasing the 
growth rate of the bacteria by supplying them 
with additional nutrients. In the case of the 
gasoline-degrading bacteria, the gasoline al- 
ready supplied the hydrocarbon, but the water- 
gasoline environment was deficient in nitrogen, 
phosphate, and oxygen. Those three nutrients 
were pumped down to the water table, bacterial 
growth increased, and the gasoline was metabo- 
lized into innocuous chemicals by the bacteria. 
As a result, it was degraded in a single year. 
Adding microbes to clean up pollution 
Genetics may have important applications in 
approaches to pollution control that depend on 
^R. L. Raymond, V. W. Jamison, J. O. Hudson, "Beneficial Stimu- 
lation of Bacterial Activity in Groundwaters Containing Petroleum 
Products," AIChE symposium series 73:390-404, 1976. 
^V. W. Jamison, R. L. Raymond, J. O. Hudson, "Biodegradation of 
High-Octane Gasoline," Proceedings of the Third International Bin- 
degradation Symposium, J. M. Sharpley and A, M. Kaplan (eds.) 
(City???? : Applied Science Publishers, 1976). 
adding microbes to the pollution site. Three 
firms— Flow Laboratories, Polybac Corp., and 
Sybron/Biochemicals Corp.— sell microbes for 
such use. Two companies select bacteria for en- 
hanced degradation acti\itv and two mutate 
bacteria to the same end, hut none of the three 
firms currently uses genetic engineering tech- 
niques. 
Some "formulations” (mixtures) of bacteria 
are designed to degrade particular pollutants, 
such as one that was used to digest the HOO.OOO 
gal of oily water that lay in the bilges of the* 
Queen Mary. After a 6-week treatment with the 
formulation, the water from the bilges was 
judged safe for disposal into the Long Beach, 
Calif., harbor. It was discharged without caus- 
ing an oil slick or harming mai’ine life.-* F1o\n 
Laboratories markets its ser\ ic(‘s to companies 
with industrial pollution pi'ohlems. It iincsti- 
gates the problem, develops a formulation to 
degrade the pollutants, and sells it. 
In addition to industrial pollution pi'ohlems. 
Flow' markets its products and ser\ i('(\s for u.se 
in sewerage systems, which collect and hold 
human wastes to facilitat(> degradation and de- 
toxification. Sludge hact(M’ia in sewerage plants 
degrade the w^aste, hut they are not pre.siMit in 
the lines that cany wastes to the treatiiuMit 
plant. As a result, gr(\ises and oils from fat dis- 
carded through gai'hage dis|)osals and I rom cos- 
metic oils and creams coat tlie inside of sewer- 
age lines and reduc(^ their carrying ca|)aeity.’ 
Cities have resisted using added microbes in 
sewerage systems. Standard te.\tl)ooks simply 
state that the ideal hactcM'ia w ill establish them- 
selves in a w'ell-|)lann('d and well-managed sys- 
tem. The idea that ''better" bacteria can l)c 
added to imjjrovfj th(‘ plant operation is not 
readily accepted. 
Fhe value of adding bacteria to large sewer- 
age sytems has not been ade(|uatel\ tested 
Because of the size of municipal .systems (w Inch 
already contain tons of sludge bacterial, some 
have argued that adding a tew .iddilion.il 
*.\uun. T.nvironmental Scirntf anil t rrhnolog\ 1.11 isn C ' 
•’R I-.. Kirkup iind I. R Srlsmi. ( il\ I ikIiW (.n-.i -. .ind 0,1. 
Pi'ohlem.s in Scwim' SysU-ms. Ptihlii Works Magarmr (Ki.'l-. 
1977. 
