Characterization of a bacteriocin produced by Prevotella nigrescens ATCC 25261

Abstract

Aims: To characterize the antimicrobial activity produced by Prevotella nigrescens ATCC 25261, and to evaluate its safety on cultured gingival fibroblasts. Methods and Results: An antimicrobial activity was obtained from purifying the culture supernatant of Pr. nigrescens ATCC 25261. Purification of the active compound was achieved with ammonium sulphate precipitation followed by anion-exchange and gel filtration chromatography. As revealed by SDS-PAGE, the active fraction was relatively homogeneous, showing a protein with an approximate molecular weight of 41 kDa. The antimicrobial compound, named nigrescin, exhibited a bactericidal mode of action against Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and Actinomyces spp. Nigrescin was stable in a pH range between 6AE5 and 9AE5, at 100°C for 10 min, and resistant to lyophilization. But its activity was lost after proteinase K treatment. Despite at very high concentrations beyond the minimum inhibitory concentration (MIC), nigrescin was not toxic to the gingival fibroblasts. Conclusion: Nigrescin is a novel bacteriocin produced by Pr. nigrescens ATCC 25261. It exhibits antimicrobial activity against species that are implicated in periodontal diseases. The absence of toxicity on the gingival fibroblasts suggests the possibility in using of nigrescin for an application in periodontal treatment. Significance and Impact of the Study: Novel evidence on nigrescin would make Pr. nigrescens ATCC 25261 attractive in biotechnological applications as an antimicrobial agent in clinical dentistry.

Isolation and Characterization of a Bacteriocin-Like Substance Produced by Geobacillus toebii Strain HBB-247

“…2). Similar results have been reported for other bacteriocins with high ([10 kDa) molecular weight, thermoleovorins [7], thermophilin ST-1 [18], nigrecin [21], cerein 8A [22], lactosporin [23].…”

Interspecies Interactions within Oral Microbial Communities

“…Although there have been a few reports regarding the existence of bacteriocins which are active against gram-negative anaerobes (84,143), none that are active against suspected periodontopathogens have yet been identified. If such bacteriocins with efficacy against these organisms can be identified, it may be possible to genetically engineer GRAS organisms to actively produce such bacteriocins for incorporation into dietary supplements as a means of controlling periodontitis.…”

“…Subsequently, the same group isolated and identified the genetic determinant for nigrescin, a 41-kDa novel bacteriocin which is produced by P. nigrescens and displays a bactericidal effect against P. gingivalis, P. intermedia, T. forsythia, and Actinomyces spp. (84).…”

The Role of Oral Pathobionts in Dysbiosis during Periodontitis Development

“…Bacteriocins from different bacteria possess different specificity against oral pathobionts. For example, bacteriocin from Prevotella nigrescens is bactericidal against P. gingivalis, but bacteriocin from P. intermedia is not (Takada et al, 1991;Kaewsrichan et al, 2004). Further analysis is required for the role of bacteriocins in the regulation of intra-species interactions and dysbiosis in the oral cavity to be understood.…”