Rhamnolipids and lactonic sophorolipids: natural antimicrobial surfactants for oral hygiene

Abstract

The findings indicate the potential value of biosurfactants for both oral hygiene and the pharmaceutical industries since there is a serious need to reduce the reliance on synthetic antimicrobials and antibiotics.

Antibacterial Activities of Sophorolipids and Nisin and Their Combination against Foodborne Pathogen Staphylococcus aureus

“…MIC of SLs was 32 µg mL −1 , and MIC of nisin was 0.5 µg mL −1 that was much lower than that of SLs (Table 1 and Figure 1). A much higher MIC (400 µg mL −1 ) of SLs was reported in suppressing S. aureus ATCC 29737 by Joshi-Navare [27] and S. aureus ATCC 14576 by Elshikh et al [28] The differences may be due to different test strains or SLs types, or different methods since culture plate method and microdilution method were used in studies of Joshi-Navare and Elshikh et al It has been reported that there were different activities of antibacterial compounds between in vitro and in vivo studies; for instance, the dosage in vivo could be much greater than the in vitro MICs obtained, and so is the SLs. [29] We studied the application of SLs in fresh milk and found good effects for milk preservation at the concentration of 500 µg mL −1 (data not shown).…”

“…MIC of SLs was 32 µg mL −1 , and MIC of nisin was 0.5 µg mL −1 that was much lower than that of SLs (Table and Figure ). A much higher MIC (400 µg mL −1 ) of SLs was reported in suppressing S. aureus ATCC 29737 by Joshi‐Navare and S. aureus ATCC 14576 by Elshikh et al . The differences may be due to different test strains or SLs types, or different methods since culture plate method and microdilution method were used in studies of Joshi‐Navare and Elshikh et al.…”

“…Furthermore, SL‐tetracycline and SL‐cefaclor combinations showed synergism against S. aureus and E. coli , respectively . Combining lactonic SLs with antimicrobial agents, such as chlorhexidine, sodium lauryl sulfate, tetracycline HCl, and ciprofloxacin, resulted in significant reduction of MIC values against pathogens important for oral hygiene . Olanya et al .…”

“…[27] Combining lactonic SLs with antimicrobial agents, such as chlorhexidine, sodium lauryl sulfate, tetracycline HCl, and ciprofloxacin, resulted in significant reduction of MIC values against pathogens important for oral hygiene. [28] Olanya et al [11] reported that combinations of SL and nisin-based sanitizer showed synergistic effect on E. coli O157:H7, but not L. monocytogenes and S. enterica. In the study of Olanya et al, the sanitizer used was not highly pure nisin but nisin-based including nisin, organic acids, and other ingredients with a low pH of 3.0 that may be detrimental to bacterial cells.…”

Microbial biosurfactants: current trends and applications in agricultural and biomedical industries

“…The evidence of the efficacy of different biosurfactants from different micro-organism in differing contexts remains a challenge. There is good evidence of the effectiveness of biosurfactants in terms of antimicrobial activity and there is increasing evidence of the benefits of biosurfactants in terms of wound healing, dermatological applications and oral care (Elshikh et al 2017b). There is promising work in the area of drug delivery but in the area of cancer treatment where biosurfactants might prove most efficacious there remains much conflicting data.…”