ISSN 1070-4272, Russian Journal of Applied Chemistry, 2007, Vol. 80, No. 2, pp. 236!240. + Pleiades Publishing, Ltd., 2007.
Original Russian Text + T.E. Nikiforova, V.A. Kozlov, N.A. Bagrovskaya, M.V. Rodionova, 2007, published in Zhurnal Prikladnoi Khimii, 2007,
Vol. 80, No. 2, pp. 236!241.
AND ION-EXCHANGE PROCESSES
Sorption Properties of Enzymatically Modified Flax Fiber
T. E. Nikiforova, V. A. Kozlov, N. A. Bagrovskaya, and M. V. Rodionova
Ivanovo State University of Chemical Engineering, State Educational Establishment, Ivanovo, Russia
Institute of Solution Chemistry, Russian Academy of Sciences, Ivanovo, Russia
Received July 3, 2006; in final form, November 2006
Abstract-The influence of enzymatic modification on the sorption properties of a short flax fiber with
respect to the Cu(II) ions was examined. The optimal parameters were determined for treatment of natural
cellulose-containing sorbent with various enzymatic preparations, B
, NCE, and protease, which affords
the maximal sorption capacity of the sorbent and the shortest time required for establishment of equilibrium.
IR spectroscopy was applied to examine changes in the structure of the substrate via rupture of inter- and
intramolecular bonds in its constituent biopolymers under the action of the enzymes.
In the context of development of resource-saving
processes, of particular interest is development of
sorption methods for removal of heavy metal ions
from aqueous solutions of varied nature, including
food media. The easy accessibility and low cost of
the waste from agroindustrial and wood-processing
sectors make them promising sorbents for this purpose
Such sorbents, however, typically exhibit poor
kinetic characteristics and a comparatively low sorp-
tion capacity. This makes the search for a procedure
for treatment of cellulose-based polymers to increase
their sorption capacity and decrease the sorption time
an important avenue in the development of new sor-
bents. Various methods  have been suggested
for treatment of cellulose-containing sorbents, includ-
ing mechanical, physical, chemical, and physicochem-
ical methods (wet grinding, freezing, plasma activa-
tion, treatment with sodium polysulfides, coloration
with active dyes, grafting of amino acid residues, etc.).
In our opinion, enzymes and enzymatic preparations
(EPs) are promising for treatment of sorbents.
Today, wide application of biotechnological meth-
ods in solving specific practical problems is limited
by the lack of a databank covering the specific
features of the influence exerted by both individual
enzymes and EPs on various substrates. This makes
examination of the impact of enzymes and their for-
mulations on biopolymers an important step in this
direction. Shibashova et al.  and Cheshkova et al.
 reported on biochemical modification of cellulose
and flax materials for textile industry.
We examined here the sorption properties with
respect to the copper(II) ions of natural cellulose-
containing material, short flax fiber, in relation to
the conditions of the enzymatic treatment.
We examined a short flax fiber, a secondary proc-
essing product of flax industry, with the composi-
tion, wt %: cellulose, 75378; hemicellulose, 9.4311.9;
lignin, 3.8; pectins, 2.933.2; waxy substances, 2.7;
nitrogen-containing substances calculated for proteins,
1.932.1; and mineral substances, 1.332.8 .
We also used enzymatic preparations
NCE, as well as the alkaline protease manufactured in
Russia. The enzymatic complex NCE comprises cel-
lulases, pectinases, and esterases, and B
lases, pectinases, esterases, and hemicellulases. Both
EPs are beige powders with a specific odor. The al-
kaline protease is produced in the form of 0.231.0-mm
light gray or light beige granules. The proteolytic ac-
tivity of the preparation is 50 000 units g
, in accor-
dance with TU (Technical Specifications) 64-13-19389
(bacteria, fungi). Solutions containing Cu(II) were
prepared by dissolving CuSO
O of chemically
Developed by gene engineering at the Chair of Enzymology,
Moscow State University.