1070-4272/02/7503-0432$27.00C2002 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 75, No. 3, 2002, pp. 432! 435. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 3,
2002, pp. 443!446.
Original Russian Text Copyright + 2002 by Porozova, Bekker, Ivshina, Karmanov, Rychkova.
OF CHEMISTRY AND TECHNOLOGY
Structural Changes of Aluminosilicate Materials
in the Presence of Rhodococcus sensu stricto
S. E. Porozova, V. Ya. Bekker, I. B. Ivshina, V. I. Karmanov, and M. I. Rychkova
Research Center of Powder Materials Science, Perm, Russia
Institute of Ecology and Genetics of Microorganisms, Ural Division, Russian Academy of Sciences,
Institute of Applied Chemistry, Ural Division, Russian Academy of Sciences, Perm, Russia
Received November 5, 2001
Abstract-The influence of rhodococci on highly porous ceramics based on celsian and cordierite porcelain
was studied by X-ray diffraction and IR spectroscopy.
The study of microorganisms involved in restora-
tion of ecosystems affected by human activity is an
urgent problem. One of these ecologically trophic
bacteria oxidizing natural and man-made hydrocar-
bons is Rhodococcus sensu stricto . Highly porous
honeycomb ceramics (HPHC) combining developed
macroporosity with the presence of channel micro-
pores [4, 5] are promising supports for biogenic
agents. However, even ceramics are affected by
rhodococci [4, 5]. Previously we found that rhodo-
cocci catalyze not only degradation of aluminosilicate
HPHC but also epitaxial processes increasing the
weight and strength of the samples. The phase com-
position of the reprecipitation products formed in
thin ceramic films of complex shape is difficult to
In this work we studied structural transformation of
aluminosilicate HPHC under the action of Rhodococ-
cus sensu stricto.
We used pure R. ruber IEGM 231 rhodococcus
. To determine the resistance of the ceramics
to the bacterial action, HPHC samples were placed in
mineral media containing 0.003% acrylamide as the
carbon source and 4.0 0 10
rhodococcus cells per ml.
The blank experiment was performed without bacteria.
We studied highly porous honeycomb ceramics based
Obtained from the Local Profiled Collection of Alkanotrophic
Microorganisms (Institute of Genetics and Ecology of Micro-
organisms, Ural Division, Russian Academy of Sciences,
on celsian and cordierite porcelain . X-ray diffrac-
tion analysis was performed on a DRON-3M diffrac-
tometer using b-filtered cobalt radiation.
The IR spectra of ceramic samples kept in the bac-
terial media for 10 months were recorded on an
IFS-66 Fourier spectrometer (Bruker, Germany) under
the following conditions: Nujol mulls prepared in
an agate mortar, KBr windows, resolution of 1 cm
100 scans. The spectra were brought to the zero base-
line. The complex bands were resolved into the com-
ponents whose location (n), half-width, and peak (D
and integral (D
) optical densities were determined.
Since powders of multiphase ceramics are structurally
nonuniform, the shape of separate bands was approxi-
mated by the Gaussian functions. Resolution of the
complex bands of the initial cordierite porcelain into
the components is shown in Fig. 1 as an example. The
parameters of these bands are presented in Table 1.
Since the intensity of the absorption bands depends
on the thickness of the absorption layer and the con-
tent of Nujol in the mull, which were not controlled,
Fig. 1. Resolution of absorption bands of the initial cor-
dierite porcelain into the components: (D) optical density
and (n) wave number.