Acid–base properties of cyanobacterial surfaces I: Influences of growth phase and nitrogen metabolism on cell surface reactivity

Cell surface acid-base properties of the cyanobacterium Synechococcus : Influences of nitrogen source, growth phase and N:P ratios

“…These findings correlate well with those of Lalonde et al (2008a) who similarly observed variability in site distribution of the filamentous, nitrogen fixing cyanobacterium Anabaena sp. PCC strain 7120 when grown under different nitrogen assimilation pathways.…”

“…Similar trends were observed by Haas (2004) for Shewanella putrefaciens, Bruinsma et al (2001) for Pseudomonas aeruginosa and Ede et al (2004) for Bacillus stearothermophilus. It is possible that ligand concentrations are increased during the exponential growth phase to facilitate the acquisition of nutrients, and are decreased for stationary and death phase cells to minimize interactions with toxic metabolites, or by the fact the cells are no longer metabolically active (Lalonde et al, 2008a). Another possibility is that bacteria will tend to initiate the production of reserve polymers, such as polysaccharides, polyphosphate and nutrient acquisition proteins, at longer incubation times and under nutrient limiting conditions (Borrok et al, 2004;Haas, 2004;Madigan et al, 2008), but continuous nutrient deprivation will tend to limit the number and size of bacteria cells.…”

“…Confidence is generally poor between the reference condition and varying N:P ratios (both increase and decrease), with amine groups being the most is possible to retain soluble cytosolic contents and evaluate the biomass as a whole for differences in proton reactivity attributable to metabolic pathway. Further to determine whether the differences in reactivity attributed here to growth conditions might be reflected in the cytoplasmic contents (i.e., in the intracellular pools of organic and inorganic compounds; Lalonde et al, 2008a). Heat-killed preparations likely differ in terms of factors such as surface area and soluble biomass components, and these changes would then have contributed excess charge relative to the other titrations presented (Lalonde et al, 2008a, b).…”

“…Previous investigations revealed that the composition of the culture media, temperature, metabolic pathway, growth phase and pH strongly affected the structural and elemental composition of the bacterial cell wall (Cox et al, 1999;Borrok et al, 2004;Haas, 2004;Hong and Brown, 2006;Yang et al, 2006). These may impart the cell surface with differing surface chemistry and charge characteristics, which could then influence the microorganism's hydrophobic and hydrophilic properties, adhesive capacities, and further affect the transport and bioremediation of contaminants (e.g., trace metals and organic pollutants) in the subsurface (Fein et al, 1997;Lalonde et al, 2008a;Castro et al, 2010). Growth phase may also impact cell wall composition and ultimately metal uptake by microorganisms.…”

“…The situation becomes more complex with the consideration of facultative metabolic pathways. For bacteria that are capable of switching amongst multiple metabolic pathways, the presence or absence of specific nutrients may dictate the expression of nutrient specific chelation agents and membrane transport proteins (Wandersman and Delepelaire, 2004;Lalonde et al, 2008a;Swanner et al, 2015).…”