[Adenine effect on the biosynthesis of 5'-inosinic acid by the mutant Brevibacterium ammoniagenes 225-5]. / Vliianie adenina na biosintez 5'-inozinovoi kisloty mutantom Brevibacterium ammoniagenes 225-5.

The effect of a temperature rise from 28 to 37 degrees C on the biosynthesis of 5'-inosine acid (IMP) by the mutant Brevibacterium ammoniagenes 225-5 was studied. The inhibitory effect of increased temperature on the IMP biosynthesis was dependent on the adenine concentration. The study of IMP synthesis on the media with different adenine concentrations showed that adenine controlled not only the synthesis of purines de novo but also, to a larger extent, so-called salvage IMP synthesis from hypoxanthine. The effect of increased temperature was identical to that of excessive adenine. Temperature rise as well as increase in adenine concentration intensified metabolic processes (increased the level of glucose consumption and the rate of nucleic acid synthesis) and restored in part cell permeability. This was indicated by the release of protein and ribose-5-phosphate into the culture fluid, and by the change in cell morphology. An optimal adenine concentration may be altered either way in response to the changes in other fermentation conditions, i.e. inoculum amount, aeration, and addition of histidine.

[Effect of medium components on the metabolism of Brevibacterium ammoniagenes-producer of 5'-inosinic acid]. / Vliianie komponentov sredy na metabolizm kul'tury Brevibacterium ammoniagenes-produtsenta 5'-inozinovoi kisloty.

The effect of different carbon and nitrogen sources on the biosynthesis of 5'-inosinic acid (5'-IMP) by the culture Brevibacterium ammoniagenes 225-5 was studied. With respect to the yield of 5'-IMP, glucose was found to be the best carbon source and urea--the best nitrogen source. The proper ratio of concentrations of carbon and nitrogen sources in the nutrient medium was very important for a high 5'-IMP accumulation. The study of the effect of phosphate and magnesium concentrations on 5'-IMP biosynthesis demonstrated that their high concentrations were needed for intensive 5'-IMP salvage-synthesis from hypoxanthine and that they did not influence the de novo synthesis of hypoxanthine.

[Study of aeration and temperature effects on the biosynthesis of 5'-inosine acid by the Brevibacterium ammoniagenes mutant]. / Izuchenie vliianiia aeratsii i temperatury kyl'tivirovaniia na biosintez 5'-inozinovoi kisloty mutantom Brevibacterium ammoniagenes.

The biosynthesis of 5'-inosine acid (5'-IMP) by the culture Brevibacterium ammoniagenes 225--5 was studied under different aeration conditions. Intensive aeration (Kv = 3.6 g O2/l.hr) was found to be necessary for an active build-up of 5'-IMP. Reduced aeration (Kv = 3.6 g O2/l.hr) caused a decrease in the 5'-IMP yield, a simultaneous increase in the hypoxanthine concentration, a reduction of cell productivity and a decrease in the glucose transformation to 5'-IMP. The temperature of 28 degrees was shown to be optimal for the biosynthesis of 5'-IMP. The total build-up of purine derivatives (5'-IMP and hypoxanthine) decreased, if the first stage (the stage of hypoxanthine accumulation) or the entire fermentation took place at 37 degrees. The temperature rise from 28 to 37 degrees at the second stage of fermentation (the stage of 5'-IMP accumulation) resulted in a temporal increase in the 5'-IMP synthesis followed by its inhibition. The most intensive synthesis of 5'-IMP in the supernatant occurred at 37 degrees and pH 7.0-8.0. A short-term heating of the culture liquid (3 hrs at 37 degrees after 72 hrs fermentation) increased the yield of 5'-IMP during heating and, to the greatest extent, bu the end of fermentation.

[Effect of addition of bases and amino acids on inosine biosynthesis by mutants of Bacillus subtilis]. / Vliianie dobavok osnovanii i aminokislot na biosintez inozina mutantami Bacillus subtilis

The relationship between the inosine biosynthesis by the Bacillus subtilis mutants VNII-genetika-265 and VNII-genetika-21 and the concentrations of adenine, guanine, uracile and amino acids was investigated. Adenine and guanine in high concentrations inhibited the inosine biosynthesis in both mutants. The mutant Gene-21 showed an increased requirement for adenine as compared with the mutant Gene-265. In the presence of uracile the pattern of the relationship between the inosine growth and biosynthesis and adenine in the mutane Gene-265 was similar to that in the mutant Gene-21. Excessive concentrations of histidine and tyrosine inhibited the inosine biosynthesis.

[Study of inosine transformation into 5'-inosinic acid by the culture of Pseudomonas trifoli]. / Issledovanie transformatsii inozina v 5'-inozinovuiu kislotu kul'turoi Pseudomonas trifolii

The transformation of inosine into 5'-inosine acid by Pseudomonas trifolii cells was studied. The synthesis of 5'-inosine acid can be performed by both live intact and dry cells. The effectiveness of inosine phosphorylation depends on the ratio of the inosine and phosphate donor concentrations and the amount of cells. The temperature and pH effect on activity of nucleoside phosphotransferase, phosphomonoesterase and 5'-nucleotidase has been studied. The influence of surface active substances and metal ions on the synthesis of 5'-inosine acid has been investigated. Optimal conditions for the inosine transformation by the above culture have been established.