Researchers Develop Value-Added Products
from Fats, Oils By Jim Core
Biodegradable industrial materials produced by microbial
fermentation of vegetable oils and animal fats are being developed by
Agricultural Research Service scientists
in Wyndmoor, Pa.
The scientists at the ARS Eastern Regional Research Center are using
inexpensive fat and oil feedstocks to contain the cost of production. The
resulting materials are alternatives to products derived from petroleum
feedstocks, according to the ERRC research team of
Solaiman, Richard D. Ashby,
and Thomas A.
Foglia. Ashby presented the findings yesterday at the 222nd
national meeting of the American Chemical
Society in Chicago, Ill.
They examined the ability of a bacterium, Pseudomonas
resinovorans, to produce poly(hydroxyalkanoate) polymers, or PHAs, when
grown on various agricultural oils and fats. Certain microorganisms produce
these plastic-like substances as a survival mechanism when fed excessive carbon
and deprived of other nutrients.
PHAs naturally break down over time, which makes them suitable
for environmentally friendly consumer and medical products ranging from
plastics and films to adhesives, depending on the fatty acid composition of the
feedstock source, Ashby reported.
These polymers are either rigid or elastomeric, depending on
their chemical structure, the organism that produces them and the fat or oil
feedstock, according to Ashby. ERRC scientists want to control PHA properties
to address suitable industrial uses. They are interested in finding strong yet
pliable materials. Recently, they discovered that a related bacterial strain,
Pseudomonas oleovorans NRRL B-778, could produce both types of PHA
polymer from a single substrate.
In related research, the scientists used a yeast, Candida
bombicola, to produce sophorolipids (SLs--microbial surfactants--from
simple sugars and a number of oils and fats. Surfactants include such
surface-active substances as detergents and emulsifiers. These biosurfactants
have properties comparable to chemically produced surfactants, are
biodegradable and are not derived from petroleum. The group collaborated with
Nuñez, a research chemist from the same research unit, to develop an
analytical method to characterize biosurfactants produced by the yeast.
ARS is the U.S. Department of
Agriculture's chief scientific research agency. Solaiman and his colleagues
work in the ERRC's Hides, Lipids and Wool