Biochemical characteristics of culture isolated from soda lake Nukhe-Nur (Barguzin depression, the Republic of Buryatia)

As a part of the study, we have isolated two alkalihalophilic bacterial cultures from the bottom sediments of the Nukhe-Nur soda lake. Based on the analysis of the 16S rRNA gene sequence, the cultures have been assigned to Alkalimonas and Paenibacillus genera. The article analyzes the extracellular peptidase activity of the strains. It is shown that secretable peptidases of the NN22n culture have narrow substrate specificity, while the peptidase of the NN22s culture has narrow substrate specificity and hydrolyzes proteins and para-nitroanilide substrates, exhibiting maximum activity in hydrolysis of L-leucyl-n-nitroanilide (LpNa), the NN22n culture produces both endopeptidases and exopeptidases, while the NN22s culture produces only exopeptidases, which indicates the specificity of a particular bacterial species and its ability to hydrolyze the same protein substrate by different enzymatic mechanisms.