A UH microbiologist has developed a process using harmless bacteria that could reduce
the cost and eliminate the
transportation problems involved in cleaning up most of
the nation's hazardous waste
John Evans, a professor of
biology at UH since 1958, has
cultured bacteria that like to eat
specific toxic wastes such as
PCBs and DDT. As they digest
cheir chosen food source, the
dangerous chemicals are safely
and inexpensively degraded.
"Unlike incineration or landfill methods, the microorgan-
sms destroy wastes at the actu-
d site, so the possibility of acci-
Jents in transport is removed,"
Evans and UH have entered
nto an agreement with Detox
ndustries, Inc., of Sugarland, to
narket the chemical-eating
Thomas Dardas, Detox's
chief executive office, said the
company has been assigned all
fights for the process under the
terms of the co-venture agreement. Evans and the University
NASA/JSC UH-Clear Lake
\da Language and Programming Support Environment
Seta Test Site. This center was
charged with evaluation a new
computer language, Ada, for
future NASA applications, including the space station.
The Ada programming language was developed by the
department of Defense as a
echnical and cost-effective solution to its increasing computer software development and
"The creation of RICIS is a
natural progression for UH-
Clear Lake, further enhancing
this University's reputation as a
center for space-related technology," says UH-Clear Lake
President Thomas M. Stauffer.
each will receive 5 percent of
the first $2 million in gross revenue, and then 1 percent afterwards, at least for an initial five-
year contract period.
In addition, Detox has established a $1 million-endowed
chair in microbiology at UH,
naming Evans as the first recipient.
"Being the chairholder permits me to do research full
time," Evans said.
In the process he developed,
bacteria are cultured to select a
particular type of organic waste
as their food source, although
they can be designed to eat
more than one kind, he said.
Evans, 61, said that as they
eat, they break down the compound, extracting carbon for
energy and leaving carbon
dioxide and water as waste pro -
The bacteria die when their
food source has been exhausted, he said, and they become, in
turn, food for larger, naturally
occurring organisms. They
leave no threat to the environment, Evans said.
He said biodegradation can
take from two months to more
than a year to complete since it
is dependent on many variables,
including the kind of contamination and the environment in
which contamination exists.
Every waste dump is different in geometry, geology and
content of organic and inorganic chemicals. Evans said or
ganic chemicals are the most
feared, most complex substances present — many of
them are heavy metal and very
difficult to biodegrade.
Evans said each site must be
analyzed and prepared in order
to "Innoculate" the degrading
"There are lots of chemical
substances in a waste dump,
and some of them are harmful
to the cultured bacteria," he
said. "They must be made resistant to them before they can
utilize the hazardous waste."
In addition to PCB and
DDT, Evans' technology can
neutralize PCPs, creosote, oil,
chlorodane, myrex, and PAHs.
Evans also has begun work
on bacterial that will eat highly
toxic dioxin, although his present research is concentrated
upon improving his existing organisms.
"I want to refine them to degrade in a shorter time and to
adapt to a wider variety of environmental conditions," he said.
Dardas said Detox has just
signed a major contract with a
major automaker to detoxify
PCB contamination on site.
Of about 300 biotechnology
firms in the United States, Detox is the only one that has been
licensed by the Environmental
Protection Agency to biologically degrade PCBs, the persistent chemicals commonly used
to cool and insulate heavy electrical equipment like transform
ers and capacitors.
However, EPA approval has
not meant acceptance by that
"The EPA is resistant to biodegradation because it is new
technology," Evans said. "They
give it theoretical homage, but
they do not recommend it to
the industry. Industry will buy,
but the EPA has not set acceptable levels for degradation."
Roger Meacham, of the regional EPA office, verified that
acceptable levels of biodegradation have not been established.
"Each site is different, so
each must be considered individually — across the board
levels are not appropriate," he
Meacham said although biodegradation is an alternative
method of dealing with Super-
fund sites, it is not the choice
for all of them.
"PCBs are very resistant to
biodegradation; they take a
long time," he said. "Another
factor to consider is air emissions, particularly when the
waste dump is in congested urban areas like many Texas sites
Science magazine has reported that biodegradation should
have an important role in the
near future as the EPA finds it
has no other alternative than to
deal with the contents of most
contaminated areas on site.
Currently, due to a lack of
incinerator capacity, there is a
2-year-old backlog of wastes to
be burned. The increase of public resistance to the establishment of more authorized waste
dumps for toxic chemicals also
indicates the necessity of a
proper disposal system.
It took Evans 10 years to develop his waste-eating organisms, and he hopes going commercial with his research will
"benefit the University and help
clean up our polluted environment."
— Marilyn Swanson