ISSN 10227954, Russian Journal of Genetics, 2015, Vol. 51, No. 7, pp. 720–724. © Pleiades Publishing, Inc., 2015.
Original Russian Text © E.S. Shumkova, A.O. Voronina, N.V. Kuznetsova, E.G. Plotnikova, 2015, published in Genetika, 2015, Vol. 51, No. 7, pp. 841–846.
The question of the treatment of terrestrial and
aquatic ecosystems that are polluted by poorly degrad
able toxic chemical compounds is central among the
key tasks that face modern ecology. Pollution by chlori
nated hydrocarbons is the second most hazardous type
for marine ecosystems (after oil contamination) .
Polychlorinated biphenyls (PCBs) belong to a group of
persistent organic pollutants (POPs), the manufacture
and use of which being presently banned by the Stock
holm Convention . However, the widescale utiliza
tion of PCBs over several decades led to significant
worsening of the ecological situation in Russia .
At the present time, PCBs are detected ubiqui
tously, even in those territories that lay at a consider
able distance from the areas in which they were man
ufactured and utilized. PCBs can be transferred by the
air flows from the middle latitudes to the Arctic region,
where they actively accumulate in the objects of the
environment. Low atmospheric and ground surface
temperatures, snow cover, and the absence of sun light
during the longlasting winter period in the Arctic
regions all dramatically decrease the rate of biological
(microbial) degradation and assimilation of PCBs,
facilitating their accumulation in water, soil, and bot
tom deposits. Therefore, monitoring of the arctic
marine ecosystems pollution appears to be of excep
The monitoring of POPs (PCBs) in the atmosphere
of the Chukotka Autonomous Region showed that the
distribution of the PCB congeners in the air follows
the composition of the sovol, a technical mixture of
PCBs widely used in the former USSR, thus implying
the possible presence of local or regional sources of
PCB pollution in the area of the probe collection
(Val’karkai meteorological station, 40 km northwards
from the Pevek town) in Chukotka. It should be also
mentioned that the PCB levels in the atmosphere in
Chukotka are among the highest as compared with
data obtained by the POP monitoring stations in the
Global Arctic [4, 5].
Approaches to the remediation of the natural envi
ronment are being actively developed at this time.
These approaches take advantage of the decomposing
bacteria and enzymes isolated from the environment.
Bioremediation approaches show an undeniable
advantage over physical and chemical means of chlo
rinated organic compound destruction because of
their safety and efficiency .
Thus, it is interesting to study microbial communi
ties that are capable of destructing biphenyl/PCBs
under low temperatures. Moreover, monitoring of the
key genes (
) involved in the processes of this toxic
compound degradation may give an idea of the biodeg
radation potential of the microbial community of
coastal sediments of the Anadyr port area in Chukotka.
Studies of the distribution and numbers of PCB
transforming bacteria (PCBTB), together with PCB
tolerant and saprotrophic bacteria, were carried out in
Diversity of Key Biphenyl Destruction Genes
in the Microbial Community of the Anadyr Bay Coastal Sediments
E. S. Shumkova
, A. O. Voronina
, N. V. Kuznetsova
, and E. G. Plotnikova
Institute of Ecology and Genetics of Microorganisms, Ural Branch of the Russian Academy of Sciences,
Perm, 614081 Russia
Department of Botany and Plant Genetics, Perm State University, Perm, 614990 Russia
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991 Russia
Received August 29, 2014
—Biphenyl 2,3dioxygenase is the key enzyme involved in the bacterial destruction of biphenyl and
polychlorinated biphenyls (PCBs), which are highly stable toxic compounds. The diversity of
encoding the biphenyl 2,3dioxygenase
subunit of biphenyldegrading bacteria from the microbial com
munity of the Bering Sea coastal sediments (the Anadyr port area) was studied. The enrichment culture was
obtained by the incubation of bottom sediments samples with biphenyl as the only carbon source. It was fol
lowed by total DNA extraction and PCR analysis with degenerate primers specific to the bacterial biphenyl
subunit genes. Subsequent cloning of the PCR products led to the identification of three
types of aromatic dioxygenase genes, which appeared to be phylogenetically close to the genes of the biphe
nyl/toluene dioxygenase and 3phenylpropionate dioxygenase subfamilies of the Actinomycetales bacteria.