выделение

Проведены сравнительные исследования липополисахаридов
(ЛПС) азотфиксирующих ризобактерий штамма Azospirillum
brasilense Sp7 и его спонтанного мутанта Sp7.K2, у которого в
результате изменений плазмидного состава наблюдалось преоб-
ладание R-форм ЛПС. Выявлены различия в химическом составе
и электрофоретическом профиле исследуемых препаратов ЛПС.
Показано, что для получения ЛПС A. brasilense Sp7.K2 с целью
проведения его дальнейших структурных исследований пред-

Isolated exopolysaccharide Streptococcus thermophilus. The conditions for the cultivation of bacteria for the maximum yield of the exopolysaccharide were selected. The bacterial culture of S. thermophilus was incubated for 48 hours in a liquid nutrient medium A. Welman at 38 °C, 180 rpm. on a thermostated shaker-incubator. As a source of carbon were used: sucrose, lactose and glucose. For the production of exopolysaccharide, the best source of carbon was sucrose. Isolation of the exopolysaccharide was carried out according to the J. Cerning method in our modification.

The comparison and assessment of the efficiency of using the precipitation of sparingly soluble metal hydroxides and fluorides for the extraction and pre-concentration of samarium isotopes from the solution simulating acidic leachate of the soil were made. It was shown that the precipitation of samarium isotopes was achieved quantitatively at the pH of about 7 and the co-precipitation of alkaline and alkaline earth elements did not exceed 20%.