Influence of extracellular polymeric substances on microbial activity and cell hydrophobicity in biofilms

Abstract

BACKGROUND: Over the last few decades, the emphasis in studies on extracellular polymeric substances (EPS) has been on the extraction and quantitative analysis methods relating to activated sludge. However, little is currently known about the relationship between EPS and microbial activity and cell hydrophobicity in heterogeneous biofilms. This paper aims to reveal the relationship between them.

Association of Quantum Dot Nanoparticles with Pseudomonas aeruginosa Biofilm

“…Once in proximity of the biofilm, observed differences in QD colocalization with the biofilm matrix materials included higher overlap coefficients with protein matrix components. Upon introduction of QD ENPs to the biofilm system, differential deposition was expected due to known differences in surface chemistry for biofilm components (Gao, 2008). However, the role of constituent biofilm matrix materials in QD deposition had not been previously measured.…”

“…The observation of a greater QD ENPs association with protein components of the biofilm may aid in both nanomaterial manufacturing waste stream treatment procedures as well as predictive models for environmental transport. Some biofilms used to purify waste streams produce protein‐to‐polysaccharide ratios of 2/1 depending on the bacterial species and location in the filter (Gao, 2008). Engineered nanoparticle deposition and removal may be enhanced with higher protein‐to‐polysaccharide ratios than those commonly found in biofilters, and waste stream treatment processes can be designed to utilize this removal mechanism.…”

“…Serving primarily as a survival niche for these microbes (Hall‐Stoodley et al, 2004), biofilms are composed of bacterial cells surrounded by extracellular polymeric substances (EPS), which include proteins, DNA, and polysaccharides (Sutherland, 2001). Extracellular polymeric substance components dictate the overall surface chemistry (surface charge and hydrophobicity) of the biofilm (Gao, 2008) and play very specific roles in overall biofilm function. For example, protein and divalent metal ions may facilitate biofilm structural changes and stabilize biofilm formation (Baum et al, 2009), while polysaccharides form the scaffolding that provides microcolonies with the ability to disperse and form based on environmental signals (Ma et al, 2009).…”

Biofilm Fixed Film Systems

“…The monosaccharide composition of EPS analyzed using high performance liquid chromatography (HPLC) shown that the EPS was enriched in galactose and glucose, with less amounts of mannose, rhamnose, fructose and arabinose. The EPS content and components were found to vary with depth in an aerobic biofilter (Gao et al, 2008). Protein was the main component of the EPS at all depth and the ratio of protein to polysaccharides was lower in the lower media near the inlet.…”

Bioremediation of petroleum wastewater by hyper-phenol tolerant Bacillus cereus: Preliminary studies with laboratory-scale batch process

“…[13][14][15][16] Fourier transform infrared (FTIR) spectra of cell membranes isolated from control bacteria and those employed in bioremediation of wastewater samples showed several absorption peaks indicating various functional groups (Fig. 3).…”