Hydrolytic and depolymerising enzyme activity of Prevotella intermedia and Prevotella nigrescens.

OBJECTIVE

Prevotella intermedia has been reported to be associated with periodontal disease whilst P. nigrescens has predominantly been isolated from more specific conditions and healthy sites. The aim of the present study was to compare the enzyme activity of these species.

MATERIALS AND METHODS

Nine strains of P. intermedia and 12 strains of P. nigrescens were studied. Lipolytic, saccharolytic, nucleolytic and proteolytic activity was determined by traditional microbiological and chromogenic substrate methods.

RESULTS

All strains hydrolysed gelatine, casein, DNA and RNA. Lipase activity was produced by all strains except P. nigrescens ATCC 33563T. Lipolytic activity of P. nigrescens strains decreased as the environmental glucose concentration was increased. Only two strains, both P. intermedia, hydrolysed benzyl-arg-rho-nitroanilide. All strains hydrolysed alkaline rho-nitrophenolphosphate (except P. intermedia DAL100), produced glycylprolyl dipeptidase activity and demonstrated elastase-like activity. All but three strains (2 P. intermedia and I P. nigrescens) hydrolysed suc-ala-ala-pro-phe-rho-nitroanilide. Overall, no qualitatively analysed enzyme activity was exclusive to all strains of either species. Quantitatively analysed activity exhibited a high degree of variability both within and between species.

CONCLUSIONS

P. intermedia and P. nigrescens degrade natural and synthetic substrates, but intra- and interspecies activity is variable.