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Microbial Biofilms-Aided Resistance and Remedies to Overcome It
Published in Bakrudeen Ali Ahmed Abdul, Microbial Biofilms, 2020
Fatty acids such as oleic acids prevent biofilm formation of S. aureus by limiting bacterial adhesion. Another fatty acid, cis-2-decenoic acid, represses and disperses biofilms of P. aeruginosa, E. coli, K. pneumoniae, P. mirabilis, S. pyogenes, B. subtilis, S. aureus, and the yeast C. albicans. Nitric oxide (NO) is an important biological messenger. It is a signal for lifestyle switching and biofilm dispersion, NO binding to HNOX, a protein harboring heme nitric oxide/oxygen-binding domain inhibits cyclic-di-GMP production which causes biofilm dispersal (Rabin et al. 2015).
Surfactants of microbial origin as antibiofilm agents
Published in International Journal of Environmental Health Research, 2021
Katarzyna Paraszkiewicz, Magdalena Moryl, Grażyna Płaza, Diksha Bhagat, Surekha K. Satpute, Przemysław Bernat
Dispersion is hypothesized to be an active form of bacterial escape (Davies 2011). Bacteria receive signals, which are transmitted through the biofilm and cause physiological changes facilitating cells release from the biofilm structure. Bacteria in biofilm can produce e.g. matrix-degrading enzymes, hydrolases, lyases, which affect the biofilm structure and allow for easy detachment of cells. There are two types of dispersion. Native dispersion occurs in the terminal stages of biofilm development and environmentally induced dispersion is observed when signals are derived from environment (Petrova and Sauer 2016). Fatty acid signaling molecules e.g. cis-2-decenoic acid (cis-DA) are responsible for native dispersion, which has been detected in P. aeruginosa (Davies and Marques 2009). Environmentally induced dispersion occurs as a result of starvation, lack of carbon sources, oxidative stress and host factors activity (Petrova and Sauer 2016). There is a hypothesis that biosurfactants (e.g. rhamnolipids) could be involved in the maintenance of the biofilm matrix structure. They enhance, probably in combination with enzymes, the degradation of extracellular polymers and facilitate the dispersal of sessile cells (Davey et al. 2003; Boles et al. 2005; Davies 2011). Dispersal can occur via the separation of single cells or sloughing of large pieces of biofilm (Purevdorj-Gage et al. 2005). Both motile cells and aggregates can initiate a biofilm in new ecological niches (Kragh et al. 2016). Cells which escape from biofilm are distinct from planktonic and sessile cells. They represent a different gene and protein expression pattern and pathogenicity (e.g. high virulence against macrophages) and release enzymes degrading the biofilm matrix.
Principles for quorum sensing-based exogeneous denitrifier enhancement of nitrogen removal in biofilm: a review
Published in Critical Reviews in Environmental Science and Technology, 2023
Ying-nan Zhu, Jinfeng Wang, Qiuju Liu, Ying Jin, Lili Ding, Hongqiang Ren
Furthermore, Tan et al. (2015) found a significant shift in dominant bacteria from potential signal quenchers (QQ) to producers (QS) during the transition from flocs to granules, suggesting microbial composition and associated signals play roles in coordinating community behavior. The cis-2-decenoic acid (cis-DA) regulates inter-specie, intra-species communication, while cis-11-methyl-2-dodecenoic acid may contribute to biofilm dispersion (Rumbaugh & Sauer, 2020).