[Screening of α-L-Rhamnosidases and Peptidases among Actinobacterium and Bacilli].

Purpose: To carry out screening of peptidases and α-L-rhamnosidases producers among actinobacterium and bacilli. Methods: The biochemical methods of α-L-rhamnosidase, elastase, caseinolytic, fibrinolytic and collagenase activity determination have been used. Results: Among 31 strains of actinobacterium and 24 strains of bacilli it was not exhibited any enzyme with elactolytic activity, while a number of actinobacterium strains displayed high collagenase activity. As to bacilli, elastolytic activity was observed only in five strains, however its level is not an interest for future investigations. Bacillus subtilis 121 and 108 exerted enough high activity (0.100 and 0.092 U/mg of protein respectively). Conclusion: The most effective producer of collagenase and α-L-rhamnosidase is actinobacterium strain 6/5 isolated from nettle zhisosphere,while peptidase with fibrinolytic activity - B. subtilis 121 and 108. We believe these strains may be perspective for further researches.

[Transmembrane potential and ATP-ase activity of the plasma membrane of bacteria exposed to heavy metals]. / Transmembrannyi potentsial i ATP-aznaia aktivnost' plazmaticheskoi membrany bakterii pri vozdeistvii tiazhelykh metallov.

Effect of heavy metals (gold, zinc and cadmium) on the ATPase activity and transmembrane potential (delta psi) as integral index of bacterial cells membrane processes intensity has been studied. It was shown that studied membrane systems of bacteria are very sensitive to the action of heavy metals and they can serve as indicators of resistance of bacterial cultures.

[Bacterial cell membrane ATPase in assessing heavy metal toxicity]. / ATFaza plazmaticheskikh membran bakterii v otsenke toksichnosti tiazhelykh metallov.

Sensitivity of membrane ATPase to heavy metals was studied in bacterial stains Bacillus cereus ATCC 14579, Bacillus cereus B4368, and Alcaligenes eutrophus CH34 was studied. The inhibition effects of metals on membrane ATPase ranged in the same order (Au > Cu > Zn > Co > Mn) as their effects on the growth of cultures. It is suggested that membrane ATPase is one of the targets for the action of heavy metal ions within the microbial cell and, therefore, its activity may serve as an indicator of their toxicity.