Showing papers on "Biofilm matrix published in 1995"
TL;DR: Genetic evidence now supports the idea that surface proximity promotes the induction of new metabolic capabilities in microorganisms, however the environmental signal responsible for this is not agreed and it is proposed that restricted diffusion at a surface plays a role in the process.
Abstract: The initial event in biofilm formation on marine surfaces is the adsorption of an organic layer. This is followed usually by microorganisms and more developed forms, but there appears to be no obligatory order in this succession. The influence of the substratum chemistry on the rate and the extent of adhesion of microorganisms is still not fully agreed because many types of organisms in differing physiological states have been used, making consensus difficult. Sometimes the surface chemistry of the substratum was not established, which further clouds the picture. Genetic evidence now supports the idea that surface proximity promotes the induction of new metabolic capabilities in microorganisms, however the environmental signal responsible for this is not agreed. We propose that restricted diffusion at a surface plays a role in the process. Support for the hypothesis that the biofilm matrix polymers are not the adhesives involved in the initial attachment of cells to surfaces is growing. Diatom adhesion is a more complicated process than that for bacteria and requires glycoprotein and protein synthesis as well as metabolic energy, i.e. it is not a passive process. Bacteria can utilize surface-bound substrates and it is possible that diatoms attached to sediment grains can exploit their attached existence also by moving along concentration gradients of dissolved organic substances in adjacent pore waters. Practical interest in the adhesion of marine microorganisms derives from their role in the degradation of man-made structures. A film of organisms only a few microns in thickness causes the hydrodynamic drag on a ship to increase considerably. Investigations of the means by which marine microorganisms adhere to surfaces have been taking place for more that 50 yr, yet we still do not understand completely the mechanisms involved.
332 citations
TL;DR: In this paper, an aerobic biofilm was characterized using confocal scanning laser microscopy (CSLM), O2 micro-electrodes, particle tracking and microinjection of fluorescent dyes.
164 citations
TL;DR: It is demonstrated that biofilm exopolymers can facilitate storage of nutrients for subsequent mineralization during periods of carbon limitation and decreased fluorescence in the absence of an exogenous carbon source resulted from degradation of adsorbed diclofop and its breakdown products by the biofilm bacteria.
Abstract: Continuous-flow cell systems were used to cultivate a degradative biofilm community with the herbicide diclofop methyl as the sole carbon and energy source. The aromatic character of this compound and its breakdown products enabled direct visualization of their accumulation in the biofilm matrix. This accumulation could be inhibited by addition of a more labile carbon source to the culture medium or by inhibition of cell activity. The fluorescence of diclofop-grown biofilms remained constant after 14 to 21 days but decreased with time when diclofop was omitted from the irrigation solution. However, this decrease was inhibited by cyanide, indicating either utilization or release of accumulated diclofop when the cells were viable. Subsequent experiments with [(sup14)C]diclofop also indicated that decreased fluorescence in the absence of an exogenous carbon source resulted from degradation of adsorbed diclofop and its breakdown products by the biofilm bacteria. These results demonstrate that biofilm exopolymers can facilitate storage of nutrients for subsequent mineralization during periods of carbon limitation.
106 citations