The antibacterial activity of rhamnolipid biosurfactant is pH dependent

Autor(es)

Ferreira, Jakeline de Freitas ^[1] ; Vieira, Estevao Alan ^[1] ; Nitschke, Marcia ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, IQSC, Dept Fis Quim, Av Trabalhador Sao Carlense 400, Caixa Postal 780, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Food Research International; v. 116, p. 737-744, FEB 2019.
• Citações Web of Science: 3

Resumo

Rhamnolipid (RL) biosurfactants have been studied as agents to control the growth of food pathogens however, to be successful applied as antimicrobial agent in food, is important to determine the effect of environmental conditions on RL activity. Once pH is a determinant factor to the development of microorganisms in food, we investigated the antimicrobial activity of RL under different pH values. The antimicrobial activity of RL against the Gram-positive pathogens L monocytogenes, B. cereus and S. aureus was pH dependent and favored at more acidic conditions while the Gram-negative Salmonella enterica and E. coli (EHEC) showed resistance at all pH levels studied. Bacillus cereus was the most sensitive bacteria showing MIC of 19.5 mu g/mL and eradication of the population was observed after 30 min with 39.1 mu g/mL of RL. The sensitivity to RL was associated with reduction on cell surface hydrophobicity and cytoplasmic membrane damage. Scanning Electron Microscopy images evidenced the cell damage promoted by RL on sensitive strains. The pH is an important factor to be considered on developing RL-based strategies to the control of food pathogens. (AU)

• Processo FAPESP: 15/22414-7 - Atividade antibiofilme e antimicrobiana de ramnolipídeos frente a bactérias de importância alimentar
• Beneficiário: Marcia Nitschke
• Modalidade de apoio: Auxílio à Pesquisa - Regular