GROUP OF BIOCHEMISTRY OF NITROGEN FIXATION

Studies in the field of nitrogen fixation and nitrogen metabolism were started in Bach Institute of Biochemistry in the laboratory of Enzymology, which was headed since 1966 by corresponding member of Russian Academy of Sciences, Professor W.L. Kretovich. These studies were continued in labs of Nitrogen Metabolism and Protein Biosynthesis in Plants, Biochemistry of Nitrate Assimilation, and Biochemistry of Symbiotic Nitrogen Fixation established in later 1980s. Laboratory of Biochemistry of Nitrogen Fixation in present state was organized in 2002. Prof. A.F. Topunov became head of the lab. Now 10 people are permanent employees of the lab, including 1 person with D.Sc. and 7 with PhD degrees. 5 post-graduate students are working in the lab.

Head of Group :

Alexey F. Topunov,
   He entered the Institute in 1976 as student preparing his Master work. In 1981 he received his PhD and in 1996 his DSc degrees. In 1993-94 Dr. Topunov worked as Invited Scientist in the Institute of Bioorganic Chemistry of Polish Academy of Sciences in Poznan, and in 1993-94 as Invited Professor in Queen’s University in Kingston (Canada). He was chief of many Russian and International scientific projects. Dr. Topunov is author of more than 130 scientific papers. He was awarded with Bronze Medal of the Exhibition of USSR Economic Achievements.
   Dr. Topunov is active in pedagogies. He is Professor of Moscow State University of Food Industry and head of joint Scientific-Teaching Center “Biochemistry and Biotechnology”. He is responsible for work with young scientists in Bach Institute of Biochemistry. Dr. Topunov is author of several textbooks for students.
e-mail: topunov AT inbi.ras.ru, 

Primary fields of activity for laboratory are studying biochemistry and energetics of symbiotic and free-living nitrogen-fixing organisms, including influence of environmental factors on organisms with different genomes. Lab is also interested in such aspects of nitrogen metabolism as connection between nitrogen fixation and nitrate reduction and metabolism of active nitrogen species. The main directions of studies are:
Peculiarities of oxygen metabolism in nitrogen-fixing nodules of legume plants and functioning of leghemoglobin – hemoglobin of legumes. Effect of stress factors on symbiotic nitrogen-fixing system of legumes. Use of knowledge of specificity of legume metabolism for selection and breeding of legume plants in different climate and soil conditions.
Regulation of metabolism of free-living nitrogen-fixing bacteria Azotobacter, including synthesis of polyhydroxybutyric acid. Elaboration and modification of production technology of biocompatible polymer - polyhydroxybutyrate and its practical use.

Enzyme metleghemoglobin reductase reducing leghemoglobin was for the first time isolated from legume nodules and studied. Scheme of leghemoglobin functioning used for description of regulation of conditions in nodules was proposed. Expression of lupine leghemoglobin gene in E. coli was done, functionally active leghemoglobin was obtained (with Institute of Bioorganic Chemistry, Poznan, Poland). Action of oxygen and nitrogen active species on myoglobin and leghemoglobin was studied. It was shown that iron-dinitrozyl complexes could reduce oxoferryl forms of these proteins. One of functions of such complexes in nodules can be detoxication of oxoferryl forms of leghemoglobin forming at oxidative stress conditions.
Influence of mutations in pea symbiotic genes on biochemical properties of nodules was studied (with Institute of Agricultural Microbiology, Saint-Petersburg). Pea gene Sym31 was identificated as the first known symbiotic gene simultaneously controlling differentiation of symbiotic compartments and nitrate-dependent regulation of nodule formation. Homology of several symbiotic genes of pea and Lotus was shown.
Studies of protein composition of seeds of some legume plants for their more active use in food industry as food additives and for protein composites was made.
Influence of different factors on synthesis of polyhydroxybutyrate by nitrogen-fixing microorganisms was studied. Strains were isolated and optimal conditions for their growing and production of pure polymer were selected. Experimental-industrial rules for obtaining biodegradable polyhydroxubutyrate plastic for technical use after its synthesis by Azotobacte bacteria were worked out. Technology of covering implant nets by polyhydroxubutyrate for obtaining their bio- and hemocompatibility, elastic properties and stability against infection was elaborated. Medico-technical requirements for synthetic surgical implant nets covered by polyhydroxubutyrate were worked out.

In the laboratory:
method for isolation metleghemoglobin reductase forms and leghemoglobin components from legume nodules was elaborated (Shleev et al. // Appl. Biochem. Microbiol. (Moscow, Engl. Ed.) 2001. V. 37. N 2. P. 195-200);
bioelectrochemical cell allowing simultaneous spectrophotometric control of the analyte was designed (Shleev et al. // Appl. Biochem. Microbiol. (Moscow, Engl. Ed.) 2000. V. 36. N 3. P. 306-309).

Patented: method for producing the pure polyhydroxybutyrate of definite molecular weight (Rus. Patent N 2201453, 18 October 2001) using its effective microbiological synthesis by Azotobacter chroococcum strain (Rus. Patent N 2194759, 18 October 2001).

Russian and Foreign Partners. Several scientific institutions in Russia and abroad are partners of the laboratory. They are Semyonov Institute of Chemical Physics, Shubnikov Institute of Crystallography, Institute of Cytology and Genetics (Novosibirsk), Bakulev Scientific Center of Heart-Vessel Surgery, Institute of Agricultural Microbiology (Saint-Petersburg), All-Russia Cardiological Research Center, Institute of Experimental Botany (Minsk, Belarus), Institute of Botany (Baku, Azerbaijan), Institute of Bioorganic Chemistry (Poznan, Poland), John Innes Center of Plant Genetics (Norwich, England), Aarhus University (Denmark), Queen’s University (Kingston, Canada), Haryana Agricultural University (Hisar, India).
Laboratory also has permanent contacts with several Moscow and regional Universities. They are: Lomonosov Moscow State University, Moscow State University of Food Industry, Moscow Pedagogical State University, Moscow Academy of Fine Chemical Technology, Bryansk State Pedagogical University, Bryansk Agricultural Academy, Kokshetau University (Kazakhstan). Students take educational practice and make their Bachelor and Master works in the lab. Many of them later became post-graduate students and employees of Bach Institute of Biochemistry. In 1998-99 student of Lomonosov Moscow State University F.N. Rozov preparing his Masters work in the lab was a winner of the Program “Soros Students”.

The main realized projects:
Projects of Russian Science Ministry Programs.
Program “Biotechnology of Russia”: project N 4, “Elaboration and creation of experimental-industrial production of polyhydroxybutyrate - ecologically pure biodegradable plastic”, 1997-2002 (Head Dr. G.A. Bonartseva).
Program “Phytobiotechnology”: “Studies of oxygen metabolism regulation in nodules of legume plants”, 1998 (Head Dr. A.F. Topunov).
Program “Elaboration of technology for producing surgical implants and threads using biocompatible and biodegradable polymer”, 2002-2004 (Head Dr. G.A. Bonartseva).
Russian Foundation for Basic Research grants.
N 96-04-50379, “Study of regulation of oxygen conditions in legume nodules and role of leghemoglobin in this process”, 1996-1997 (Head Dr. A.F. Topunov).
N 99-04-48640, “Study of mechanisms of regulation of oxygen conditions in nitrogen-fixing legume nodules”, 1999-2001 (Head Dr. A.F. Topunov).
N 01-04-06432, grant for young scientists, 2001 (Head N.E. Petrova).
N 03-04-49074, “Influence of oxidative and nitrate stresses on nitrogen-fixing nodules of legume plants”, 2003-2005 (Head Dr. A.F. Topunov).
INTAS grant. N 01-2322, "Cloning and analysis of key legume symbiotic genes with the use of synteny between pea (Pisum sativum L.) and Lotus japonicus (Regel.) K. Larsen genomes", 2002-2005 (Team leader Dr. A.F. Topunov).
International Program “Interbioazot-2000”. “Role of leghemoglobin in symbiotic nitrogen-fixing system of legume plants”, 1987-1996 (Head Dr. A.F. Topunov).
“Influence of different factors on synthesis of polyhydroxybutyrate by nitrogen-fixing microorganisms”, 1991-1996 (Head Dr. G.A. Bonartseva).
Running projects:
Мegaproject of Russian Science Ministry. Project N 18, 2005-2006 (Team leader Dr. G.A. Bonartseva).
Joint project of Russian and Byelorussian Foundations for Basic Research. N 06-04-81054, “Molecular mechanisms of formation of lupine resistance to anthracnose”, 2006-2007 (Head Dr. A.F. Topunov).
Program of Russian Education Ministry. Project N 2.2.1.1.8916, “Extending and development of joint scientific-teaching center of Moscow State University of Food Industry and Bach Institute of Biochemistry for training high-quality specialists in different fields of biotechnology”, 2006-2007 (Head of scientific part Dr. A.F. Topunov).

Last review: 17 June, 2006

© A.N.Bach Institute of Biochemistry of the R.A.S., 2001-2007