Taxonomic status of the agent of cereals pale-green dwarf and proposition of founding in the class of Mollicutes, of the order III Acholeplasmatales, family I Acholeplasmataceae, genus II Pluraplasma gen. nov., and its first species Pluraplasma granulum sp. nov.

The paper includes the data concerning the taxonomic status of the agent of cereals pale-green dwarf (ACPGD) which has been defined as the phytopathogenic variant of the mollicute Acholeplasma laidlawii and called A. laidlawii var. granulum. Since besides phytopathogenicity ACPGD has such fundamental differences from A.laidlawii as: a very large genome of 2200 thousand pairs of nucleotides (t.p.n.) to 2310 t.p.n. that practically equals a sum of genomes of A. laidlawii (1600 t.p.n.) and phytoplasmas (710 t.p.n.); two forms of DNA-dependent RNA-polymerase (one form functions in A. laidlawii); a capacity to form extracellular fructosobisphos-phatase which looks like its hypothetical phylogenetic precursor a bacteria Bacillus subtilis; availability of numerous fermentative activities which are absent in acholeplasmas; peculiar relation to sterols availability in nutrient media that is not characteristic of all the known acholeplasmas; extremely rich, as to quantity and quality, composition of antigens to react almost homologously with antibodies to representatives of Acholeplasma genus and separate species of Mycoplasma genus; great similarity (above 88 %) of sequences of 16S rRNA of ACPGD and representatives of Phytoplasma genus and other properties described in the paper, so it is concluded, that proceeding from its characteristics, ACPGD cannot be referred to either of the existing genera of the Mollicules class, because according to all its features this mollicute is a transition form of the microorganism, it is the hitherto unknown chain between these genera of mollicutes and sporiferous bacteria, ACPGD is a probable representative of mollicute precursor with genome of about 1600 t.p.n. and, first of all, of genera Acholeplasma and Phytoplasma which arised as a result of the evolutionary splitting of its genome. On this basis, it is recommended to found for ACPGD in the Mollicutes class, order III Acholeplasmatales, family I Acholeplasmataceae, a new genus II Pluraplasma gen. nov. and its first species Pluraplasma granulum sp. nov., the strain 118 being its typical representative.

[On the nature of the pathogen of pale-green dwarfism in cereals].

The paper presents more precise data concerning optimal temperature demands to growth of white-yellow dwarfness of cereals (WYDC) identified before as Acholeplasma laidlawii var. granulum, its relation to sterols and genome properties was determined using pulse-electrophoresis. It was established that the agent strains 84 and 118, characterized by phytopathogenicity, grew most intensively at 32 degrees C; they behaved as mesoplasmas but, as it had been found, they were capable to synthesis of carotenoids and displayed close serologic affinity for A. laidlawii PG8. That is, the above strains are typical acholeplasmas capable to live in leafhoppers which carry a disease and in cereals plants and cause a disease with typical symptoms of "yellows" in the latter. Molecular weight of the strain 84 genome was 2200 t.p.n. (GC = 33 mol %); in strains 118 it was 2310 t.p.n. (GC = 34.2 mol %). Allowing for the fact that molecular weight of genome of A. laidlavii var. granulum is almost by 1/3 (1600 + 710 t.p.n.) more than that of A. laidlawii PG8 genome, the authors think that the agent of WYDC is the evolution precursor (or one of precursors) which initiated the Acholeplasma and Phytoplasma genera as a results of splitting of their genomes.

[The binding and absorption by mollicute cells of antisignature analogs of oligodeoxyribonucleotides]. / Sviazyvanie i pogloshchenie kletkami mollikutov antisignaturnykh analogov oligodezoksiribonukleotidov.

Processes of absorption and uptake of phosphorothioate, phosphorodithioate and methylphosphonate analogs of oligodeoxynucleotides which are complementary to "signature" 16S rRNA sequences by cells of Acholeplasma laidlawii PG-8. Mycoplasma fermentans PG-18 and Mycoplasma pneumoniae FH have been investigated. Distinctions in efficiency of absorption by given cells of phosphorothioate and methylphosphonate analogs of oligonucleotides are found out. So, the level of thioates sorption by the cells of A. laidlawii PG-8 exceeded a share of methylphosphonates binding with these cells 5 times as high. A fact of significant accumulation of thio- and dithioate analogs of oligonucleotides by the mollicute cells is established. The intracellular concentration of these compounds in all investigated microorganisms exceeded extracellular one 10(4)-10(5) time. On the basis of obtained experimental data the assumption is made on existence in mollicute cells of two various mechanisms of uptake of analogs of oligonucleotides bearing a negative charge in sugar-phosphate backbone and nonionic oligonucleotide analogs.

[The inhibition of translation in vivo in Mollicutes by thiophosphate analogs of oligodeoxyribonucleotides]. / Ingibirovanie transliatsii in vivo u mollikutov tiofosfatnymi analogami oligodezoksiribonukleotidov.

It is shown that the concentration of "antisignature" phosphorothioate analogs of oligodeoxynucleotides, complementary to the region of 165 rRNA Acholeplasma laidlawii PG-8 and Mycoplasma fermentans PG-18 responsible tor binding with ribosomal protein S4 being 0.5--1 microM synthesis of proteins in vivo decreases to 70%. A model of mechanisms is suggested to block oligonucleotides of the process of in vivo translation in mollicutes by "antisignature" phosphorothioate analogs. The advantages of the use of antisense oligonucleotides complementary to functionally significant plots of 16S rRNA to inhibit the in vivo translation are discussed in comparison with oligonucleotides, 5-nontranslated regions of mRNA serving a target for them.

[The sorption of antisense oligodeoxyribonucleotides by Mycoplasma cells]. / Issledovanie sorbtsii antismyslovykh oligodeoksiribonukleotidov kletkami mikoplazm.

The paper deals with kinetics of binding of antisense oligodesoxyribonucleotides, complementary to certain sequences 16 S RNA of mollicutes, by the cells of three representatives of class Mollicutes: Acholeplasma laidlawii PG-8. Mycoplasma pneumoniae FH and M. fermentans PG-18. It is shown that binding of antisense oligonucleotides by the mollicute cells depends on temperature and age of cultures. The highest level of sorption of labelled antisense oligodesoxyribonucleotides by the cells of mycoplasmas corresponded to the phase of logarithmic growth of each of the studied mollicute strains. The lengthening of nucleotide chain from 5 to 15 nucleotide bases did not result in the decrease of sorption of the studied oligodesoxyribonucleotides by the mollicute cells.

ABO system of blood groups in people and their resistance to certain infectious diseases (prognosis).

Natural resistance to many infectious disease which to certain extent depends on the blood group of a person is inherent in people. As is known, human erythrocytes possess the surface antigens A, B, AB that determine the groups of blood. Blood group O erythrocytes do not possess these antigens but blood serum of such people have antibodies to A and B antigens. In people with blood group A there are antibodies to antigen B and vice versa. Human blood of AB group does not contain antibodies to erythrocyte antigens of other blood groups. This determines natural resistance of people to many infectious diseases whose agents have antigens on the surface of their cells that are similar to antigens of one or another group of blood. Thus antigens similar to those of blood group A erythrocytes are localized on the agents' cells, such agents are neutralized by natural antibodies of blood groups O and B. When antigens similar to those of blood group B erythrocytes are localized on the agents' cells, that is the obstacle for them when affecting people with blood group A and B whose serum includes a lot of antibodies to these antigens. Only people with blood group AB are most sensitive to infectious diseases which agents carry antigens A, B or both A and B on their cells, since blood of such people does not contain the corresponding natural antibodies. To illustrate the above said the author gives a prognosis of possible affection of people by most pathogenic mycoplasmas whose cells possess antigens similar to those of erythrocytes of one or another blood group.

Molecular biological bases of resistance to HIV/AIDS (the hypothesis with elements of the theory).

Proceeding from the structure and function of the shell glycoprotein gp120 of the human immunodeficiency virus (HIV) and receptor glycoprotein CD4 on target cells for this virus, the author assumes that in nature there is genetically determined human resistance to the HIV infection and AIDS. This resistance manifests itself indirectly via products of the glycosylation system and via the composition and order of amino-acid residues in receptor CD4 sites responsible for interaction between the receptor and glycoprotein gp120. The author thinks that people in whom the glycosylation system determines either B(III) or AB(IV) blood groups are potential subjects of the HIV infection. But development of AIDS necessitates some conditions more, one of them is susceptibility of the human organism to be infected with mollicute Mycoplasma fermentans. This mycoplasma is able to recognize terminal NeuAc alpha 2-3 Gal in the composition of oligosaccharides of gp120, which permits it to adhere HIV virions on itself and then to transport them directly to the cells expressing receptor CD4 and having oligosaccharides of the same terminal structure. Oligosaccharides of glycocalyx of the mycoplasma protect it from the action of the human immune system and the mycoplasma, having "transported" HIV virions to target cells combines with membranes of the latter, stimulates formation by them of interleukin-1 and tumour necrosis factor, the known effectors of this virus reproduction. On the basis of all these factors the author identifies four types of human resistance to HIV/AIDS.

[The ability of the oligodeoxyribonucleotides complementary to the 3'-terminal segment of 16s-rRNA in Mollicutes to suppress translation in their ribosomes in an in-vitro system]. / Sposobnost' oligodezoksiribonukleotidov, komplementarnykh 3'-kontsevomu uchastku 16S-rRNA mollikutov, podavliat' transliatsiiu na ikh ribosomakh v sisteme in vitro]

Effect of oligodesoxyribonucleotide, complementary to 3'-end sequence (3'-UCUUUCCUCCAC) of 16S-rRNA of mollicutes, and its phenasine derivatives on the process of translation of mollicute has been studied in the system of in vitro translation, created on the basis of ribosomes of Acholeplasma laidlawii var. granulum str. 118 and germ extracts of the wheat and optimized in respect of the temperature (23 degrees C), translation time (70 min), concentration of potassium and magnesium ions (150 and 5 mM, respectively). It is shown that acholeplasma ribosomes are most efficiently inhibited (60%) under their interaction with oligonucleotide containing one phenasine insert on the 3'-end, nonmodified oligonucleotide exerted a bit less inhibiting effect (58%). Oligonucleotide containing intercalating inserts in 3'- and 5'-positions manifested the least inhibiting effect (35%). It is noted that the efficiency translation inhibition by synthetic oligonucleotides is conditioned by nuclease activity of the system and by the length of the section of active binding of oligonucleotide with the sequence target on rRNA. It is supposed that oligonucleotides complementary to certain unique rRNA sequences can become promising highly specific drugs for prophylaxis and treatment of mycoplasmoses.

Possible monosaccharide composition of glycopolymers located on the external side of membranes of cells of some mollicutes.

Monosaccharide composition of glycopolymers of five mollicutes (Mycoplasma pneumoniae FH, M. hominis PG 21, M. fermentans PG 18, Acholeplasma laidlawii PG 8 and A. laidlawii var. granulum 118) integrated with their membrane has been studied by means of nine plant lectins with certain carbohydrate specificity labelled with colloid gold. Monosaccharide composition of glycopolymers depends both on the mollicute species and on its capacity to evoke diseases in different microorganisms. Thus genetically relative A. laidlawii PG 8 (saprophytic microorganism) and A. laidlawii var. granulum 118 (an agent of pale-green dwarfness of cereals) have the ratio between N-acetyl-D. galactosamine and N-acetyl-D-glucosamine 2:1 and 1:2, respectively. Large amounts of such exotic sugar as L-fucose have been found in M. hominis PG 21, M. fermentans PG 18 and A. laidlawii PG 8. L-fucose plays the basic role in disguising cells of these mollicutes in human organism (as O(H)-group blood erythrocytes), which permits these mollicutes disseminating through the whole organism. The composition of extracellular glycopolymers of mollicutes is discussed to reveal their role in the processes of adhesion and specialization (organotropism) of these microorganisms in populating the corresponding organs and tissues of macroorganisms.

[Mono- and polyvalent synthetic sialosides as inhibitors of Mycoplasma pneumoniae adhesiveness]. / Mono- i polivalentnye sinteticheskie sialozidy kak ingibitory adgezivnosti Mycoplasma pneumoniae.

Nine mono- and polyvalent sialosides as substances inhibiting adhesive properties of mycoplasma Mycoplasma pneumoniae--the agent of human atypical pneumonia have been studied in the reaction of hemagglutination (RHA) using solid-phase variant of ELISA-test ("sandwich"--variant), which is based on the competition for specific binding in RHA between the studied syalosides and sialylglycoproteins of fetuin conjugate with horseradish peroxidase. Of seven polymers--P alpha.12.ONa(N1), P alpha.12.EA(N2), P alpha.12.NH2(N3), P alpha.12.AES.10.ONa(N4), P alpha.12.Hg.20.ONa(N6), P20.SLea.NH2(N7), as well as monomer alpha-Bn Neu5Ac and fucoidan the polymers 5, 2, 4 and 7 in concentrations as to the content of sialic acid 1.0; 1.3; 1.35 and 10.0 M, respectively, most efficiently (up to 98%) inhibited the adhesiveness of M. pneumoniae. Polymeric sialosides 3, 6 and 1 proved less active and, the concentration of sialic acid in the composition of their molecules being 10.0 microM, inhibited adhesiveness of M. pneumoniae by approximately 77, 75 and 62.5%, respectively. Antiadhesive activity of fucoidan and monomer proved too low under concentration of these substances as to the content of sialic acid in them 25 microM: they decreased the ability to adhesion in M. pneumoniae by 33 and 56%, respectively. This proved that polyvalent sialosides 2, 4, 5 and 7 are promising for creation of drugs for treatment and prophylaxis of human pneumonias of mycoplasmal etiology on principally new basis with regard for the properties of the disease agent.

[The inhibition of Mycoplasma pneumoniae adhesion in a fetuin test system by synthetic analogs and polymeric forms of neuraminic acid]. / Ingibirovanie adgezii Mycoplasma pneumoniae v fetuinovoi test-sisteme sinteticheskimi analogami i polimernymi formami neiraminovoi kisloty.

Eight glycosides and structural analogues of neuraminic acid as well as eight polymeric forms of N-acetyl neuraminic acid have been studied for their inhibitory effect on adhesion of Mycoplasma pneumoniae. Maximum inhibiting effect among low-molecular compounds was manifested by 2-->3 sialyllactose which, being used in concentrations 5.0 and 10.0 micrograms/ml, inhibited adhesion of mycoplasmas by 76 and 87%, respectively. These indices for other derivatives in the above mentioned concentrations were as follows (%): 2-->6 sialyllactose, 31 and 74%; alpha-Me-glycoside NeuAc, 75 and 85%; alpha-Bn-glycoside-N-trifluoruracetyl NeuAc, 30 and 63%; alpha-Bn-glycoside NeuAc, 32 and 59%; alpha-Bn-glycoside-4-epi-NeuAc, 20 and 27%; beta-Bn-glycoside NeuAc, 2-4%; beta-me-glycoside NeuAc, 4-5%. The maximum inhibiting effect (50% inhibition at concentration 2.5 mumol) among polymeric forms was exerted by the conjugate alpha-benzeneglycoside with polyacrylic acid containing 12 mol% of NeuAc. Conjugates with 8, 16 and 20 mol% of NeuAc possessed a bit less activity. The 50% concentration for them was 5.3, 3.1 and 8.3 mumol, respectively. Polymeric forms on the basis of polyacrylamide proved less active.

[Oligodeoxyribonucleotides complementary to sections of the mollicute ribosomal operon as transcription inhibitors in vitro]. / Oligodezoksiribonukleotidy, komplementarnye uchastkam ribosomal'nogo operona mollikutov, kak ingibitory transkriptsii in vitro.

Antisense oligodeoxyribonucleotides have been studied for their effect on the transcription in vitro in mollicutes. A synthetic fragment of DNA [symbol: see text] complementary to that part of DNA which codes the 1510-1521 area of the 3'-terminal sequence 16S-pRNA of all mollicutes was used in the study as well as its modifications by imidasophenasine derivatives: [symbol: see text], [symbol: see text] [symbol: see text]. Maximal inhibition of the mollicute transcription in vitro was observed with 100 nM oligonucleotide concentration. Lower or higher concentrations were less effective. Transcription initiated by RNA-polymerase of M. fermentans PG-18 (a mollicute strain referring to AIDS disease) proved to be the most sensitive to the effect of modified oligonucleotide: it was inhibited by 75-80%. It is concluded that modified oligonucleotides exert a dual effect on transcription: firstly, they participate in nonspecific interaction with RNA-polymerase which induces insignificant inhibition of transcription and, secondly, they complementary interact with homologous sections of one-stranded DNA-matrix and block the RNA synthesis. Binding of modified oligonucleotides with DNA is rather strong.

[The physicochemical properties of the DNAse of Mycoplasma fermentans PG-18]. / Fiziko-khimicheskie svoistva DNK-azy Mycoplasma fermentans PG-18.

Physical and chemical properties, as well as polypeptide structure of DNAse from Mycoplasma fermentans PG-18, have been determined. The enzyme in a native form exists probably as a decamere (10X34 kD) and manifests maximal activity at weak alkaline pH range. The temperature optimum of the enzyme is --37 degrees C. DNAse appears to be Mg2+-dependent and has its maximal activity at 10 mM MgCl2. EDTA completely inhibits DNAse activity. The given DNAse has been determined to cleave a phosphodiether bond in 3'-position of deoxyribose and to have both exo- and endonuclease activity, since it has hydrolized both native linear doublestranded DNA and closed-circle plasmid DNA.

[Inhibitors of nucleic acid synthesis as a means of identifying the forms of DNA-dependent DNA polymerases in Acholeplasma laidlawii PG-8 and of determining their functions]. / Ingibitory sinteza nukleinovykh kislot kak sredstvo identifikatsii form DNK-zavisimykh DNK-polimeraz Acholeplasma laidlawii PG-8 i opredeleniia ikh funktsii.

Antibiotics, inhibitors of nucleic acids' synthesis from the group of chromomycins (olivomycin of sodium salt), anthracyclines (carminomycin and doxorubicin) and streptonigrin (bruneomycin) have been studied for their effect on DNA synthesis in vitro performed by DNA polymerases (1st and 2nd forms) of Acholeplasma laidlawii PG-8. It has been stated that olivomycin inhibits the function of both the first and second forms of DNA polymerases in proportion to an increase of the antibiotic concentration in the medium. Carminomycin in the concentration of about 1 microgram/ml almost completely inhibited the activity of both DNA polymerases. However, doxorubicin also belonging to the group of anthracyclins completely inhibited the activity of the first form of DNA polymerase in the concentration of 1 microgram/ml and practically has no effect in the concentration up to 100 micrograms/ml on the activity of the second form possessing 3'-->5'-function. Streptonigrin also proved to be suitable for differentiate the forms of DNA polymerases and to determine their functions. The first form of DNA polymerase with 5'-->3'-polymerase and exonuclease functions was not sensitive by this antibiotic in the concentration of 1000 micrograms/ml, while the activity of the second form of DNA polymerase with 3'-->5'-exonuclease functions was fully inhibited by this concentration of the antibiotic in the medium. The combination of doxorhubicin and streptonigrin in the medium can be used to determine the form of DNA polymerases and to identify their 5'-->3'- or 3'-->5'-exonuclease function and for selectivity inhibition of the function of one or another DNA polymerase in the medium.

[The inhibitory action of 6-azacytidine on Mollicutes and its proposed mechanism]. / Ingibitornoe deistvie 6-azatsitidina na mollikuty i ego predpolagaemyi mekhanizm.

6-Azacytidine (6-AC) is shown to have an inhibitory effect on the Mollicutes of the different systematic position. The growth of type strains of Mollicutes (Acholeplasma laidlawii PG-8, Mycoplasma pneumoniae FH and M. fermentans PG-18) completely ceased in the nutrient medium at concentration of the above substance in it within the range of 125-250 micrograms/ml. 50% inhibiting concentration of 6-AC equaled: for M. fermentans PG-8: 23.43 micrograms/ml; M. pneumoniae FN: 46.8 micrograms/ml; Acholeplasma laidlawii PG-8: 62.5 micrograms/ml. 6-AC concentration 5 micrograms/ml decreased the process of DNA-dependent DNA synthesis in the in vitro system more than by 60%. 6-AC exerted less effect on the DNA-dependent RNA synthesis in the in vitro system: at different concentrations of 6-AC (up to 400 micrograms/ml) RNA synthesis decreased only by 20%. Translation on ribosomes of Mollicutes in the in vitro system completely ceased at 6-AC concentration 100 micrograms/ml. The results obtained indicate that for 6-AC in cells of Mollicutes and, possibly, for other microorganisms there are two targets: ribosomes and DNA-dependent DNA-polymerase. Total effect of blocking of the translation and replication processes by 6-azacytidine causes death of Mollicutes. Since 6-AC has no harmful effect on the human cells, it can be used as an efficient method for treatment of respiratory and urogenital diseases induced by Mollicutes.

[The kinetic and functional characteristics of DNA-dependent DNA-polymerases in Acholeplasma laidlawii PG-8]. / Izuchenie kineticheskikh i funktsional'nykh kharakteristik DNK-zavisimykh DNK-polimeraz Acholeplasma laidlawii PG-8.

The kinetic and functional characteristics of I and II forms of DNA-dependent DNA-polymerases of Acholeplasma laidlawii PG-8 have been studied. It is stated that I form of DNA polymerase possesses 5'-3'-exonuclease activity and is a typical replicase; II form of DNA-polymerase possesses both 5'-3'-polymerase and 3'-5'-exonuclease activity and is, evidently, a reparase. Both forms of enzyme give preference to poly(U)- and poly(A)-matrices having extremely high activity on these polymers. The enzymatic reactions realized by both forms of DNA-polymerases are described by the first-order equation. The calculated Michaelis-Menten constants equaled 180 and 250 microM for I and II forms of polymerases, respectively. It indicates that affinity to substrate in II form of polymerase is one-third higher than in I form of enzyme.

[The isolation and purification of a nonspecific DNAse from Mycoplasma fermentans PG-18]. / Vydelenie i ochistka nespetsificheskoi DNK-azy Mycoplasma fermentans PG-18.

Nonspecific endogenic DNAase has been isolated from biomass of Mycoplasma fermentans PG-18 cells and purified to the homogeneous state. The scheme of isolation consists of purification stages on columns with phosphocellulose, DNA-cepharose CL-8B and phenylcepharose. DNAase was not bound to phosphocellulose, its volume was equal to zero. Then this DNAase was passed through column with DEA-cepharose CL-6B (elution by gradient KCl from 0.1 to 1.8M): enzyme was eluted at KCl concentration in the eluting buffer from 0.1 to 1.2 M. The enzyme was purified to the homogeneous state on column with phenylcepharose (elution by linear gradient of ethylene glycol from 30 to 80%): enzyme was eluted at the concentration of ethylene glycol in the eluting buffer from 43 to 80%. According to data obtained using gel-electrophoresis, under the denaturing conditions molecular mass of enzyme in acrylamide gel was 34 kDa.

[The isolation of ribosomes from Acholeplasma and the study of their physicochemical characteristics]. / Poluchenie ribosom akholeplazm i issledovanie ikh fiziko-khimicheskikh kharakteristik.

Ribosomes are produced from Acholeplasma laidlawii PG-8 and A. laidlawii var. granulum str. 118. It is proved as possible to use the standard method of differential centrifugation for isolation of mollicute ribosomes. The physico-chemical properties of acholesplasma ribosomes are studied. The protein content for A. laidlawii PG-8 amounted to 39.6%, rRNA content--60.4% and for A. laidlawii var. granulum--39.1 and 60.8%, respectively. The RNA: protein ratio equals 1.5:1, the ratio of optic density indicates at 260 and 280 nm--2, that is peculiar to treated preparations of ribosomes. Sedimentation coefficient of acholeplasma ribosomes is 70S. The produced preparations of acholeplasma ribosomes can be used subsequently for creating the system of translation in vitro to study the biosynthesis processes of mollicute protein.

[The effect of physicochemical factors on the activity of DNA-dependent DNA polymerases in Acholeplasma laidlawii PG-8]. / Vliianie nekotorykh fiziko-khimicheskikh faktorov na aktivnost' DNK-zavisimykh DNK-polimeraz Acholeplasma laidlawii PG-8.

The biological and physico-chemical properties of DNA-dependent DNA-polymerases of Acholeplasma laidlawii PG-8 have been studied. The optimal parameters of maximal enzymatic activity are determined. It is stated that N-ethylmaleimide in concentration of 1 mM activated DNA-polymerase I by 52%, whereas DNA-polymerase II with reagent concentration of 0.5 mM demonstrated the peak of activity exceeding the control only by 10%. Spermidine in concentration of 1.5 mM for the first form of DNA-polymerase and 0.15 mM-for the second one increased the ability of both forms of polymerases to synthesize DNA by 10%. Aphidicolin added to the reaction medium up to concentration of 10 mg/ml decreased activity of forms I and II of enzymes by 83 and 68%, respectively. The presence of 0.6 mM of EDTA in the medium also negatively affected the activity of polymerases inhibiting it by 83% in form I and by 77%-in form II.