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Programmable nucleases are the most important tool for manipulating the genes and genomes of both prokaryotes and eukaryotes. Since the end of the 20th century, many approaches were developed for specific modification of the genome. The review briefly considers the advantages and disadvantages of the main genetic editors known to date. The main attention is paid to programmable nucleases from the family of prokaryotic Argonaute proteins. Argonaute proteins can recognize and cleave DNA sequences using small complementary guide molecules and play an important role in protecting prokaryotic cells from invading DNA. Argonaute proteins have already found applications in biotechnology for targeted cleavage and detection of nucleic acids and can potentially be used for genome editing.

Lipid-1a-phosphatase LpxE cleaves the phosphate group in the first position of lipid A of lipopolysaccharide in Gram-negative bacteria, which reduces toxicity and reactogenicity of bacterial endotoxin while maintaining its immunogenicity. Treatment with these enzymes in preparations of recombinant proteins obtained in bacterial producers, for example, in E. coli, may find application in the purification techniques of various pharmaceutical substances, primarily various protein components of vaccines. This work is devoted to the creation of an efficient method for obtaining an F. tularensis LpxE soluble protein in a heterologous expression system based on E. coli. Optimization of the bacterial production of LpxE enzyme is achieved by creating a SUMO-LpxE chimeric protein in which the SUMO polypeptide acts as a folding catalyst and an affinity target carrier for purifying the expression product. An additional increase in the level of synthesis of LpxE and reduction of its toxicity for a bacterial strain is achieved against the background of superproduction of bacterial periplasmic chaperones encoded by an auxiliary low copy plasmid. Subsequent chromatographic purification of the target recombinant protein involves the use of affinity metal chelate chromatography and a SUMO protease cleavage step of the SUMO peptide carrying the His6 N-terminal peptide with the reduction of natural primary structure of the enzyme. The developed method makes it possible to obtain a highly purified active enzyme LpxE F. tularensis with a yield of 0.26 g/L of bacterial culture without fermentation.

1. The size of the austenite grain of 20Kh steel depends after TCT on the cooling rate from the temperature of the upper cycle (tu.li). 2. TCT with slow heating (vk=5–10 K/min) and cooling from tu.li at rates 10–100 K/min makes possible the reduction of austenite grains from No. 4 to No. 11-12.

1. The strength of low carbon steel after hardening with accelerated heating depends on the degree of precipitation hardening of the austenite inherited by the martensite. 2. A different degree of precipitation hardening of austenite leads to a difference in the mechanism of the process of its recrystallization, and this determines the growth of the austenite grain: a) the α→γ-transformation is concluded by refining of the austenite grain; on the curve of the change of grain size of austenite in dependence on the temperature we find one minimum connected with the recrystallization of austenite (quenching temperature 950°C, heating rate vf=10 deg/sec, initial processing is normalization); b) the α→γ-transformation is concluded by refining of the austenite grain; on the curve of the temperature dependence of the grain size of austenite we find two minima connected with the recrystallization of the austenite (quenching temperature 930 and 1000°C, vf=10 deg/sec, initial treatment is cold working with a degree e=50%).

1. In the process of rapid heating (vφ=14 deg/sec) of annealed steel 40Kh the original austenite grains (grade 9) are refined twice — at the end of the α→γ transformation at 860° (to grade 10) and at 950° (to grade 13). 2. On the basis of the data obtained, we propose that nucleation and growth of austenite grains may occur by means of the α→γ transformation with formation of finer austenite grains than the original grains and additional refining at a higher temperature, evidently due to recrystallization. 3. It is recommended that the data obtained on austenite grain refining as the result of accelerated heating be used in selecting induction hardening conditions for steel in the high-strength condition.

1. The newly devised method of thermal cycling including heating at the rate of 5 deg/min to Tu.Zm (5–10°C higher than Acs) with subsequent slow cooling to 5–10°C below Ar1 makes it possible within three to five cycles to refine the austenite grain of steel 20Kh to No. 11; this increases impact toughness after final cooling in air to a value 1.5–2.5 times as high as after normalization and thermal cycling with accelerated heating. 2. In the fine austenitic grain, obtained in thermal cycling with slow heating and cooling, phase strain-hardening does not occur, and in consequence, after final cooling in water or oil from the upper limit of the cycle, the impact toughness of steel 20Kh increases more than 3 times while strength and ductility are high compared with thermal cycling with accelerated heating in which the phase strain-hardening of the austenite is retained.

1. A heat treatment for 85 spring steel (harden or normalize from 1000°C, reharden with heating to 840–870°C at a rate of 5 deg/sec, and temper at 250°C) has been developed making it possible with an elongation of 8% to increase the tensile and yield strengths of 85 steel by more than 50% in comparison with the standard heat treatment. 2. The increase in strength properties was caused by homogenization of the austenite in the first heating for hardening and grain refinement as a result of recrystallization of the austenite in the second heating for hardening.